Insulin is a two chain polypeptide having 51 amino acids and molecular weight about 6000.
It has two amino acid chains called α and β chains, which are linked by disulfide bridges. The α-chain of insulin contains 21 amino acids and β-chain contains 30 amino acids.
It is primary hormone which is responsible for controlling the storage and utilization of cellular nutrients.
biological Insulin, synthesis, factors affecting synthesis, primary structure of insulin, different insulin preparations, mechanism of action of Insulin and pathway, physiological & biochemical effect of Insulin, Disorders related with insulin production, treatment strategy, Drugs Used to treat Diabetes Mellitus
biological Insulin, synthesis, factors affecting synthesis, primary structure of insulin, different insulin preparations, mechanism of action of Insulin and pathway, physiological & biochemical effect of Insulin, Disorders related with insulin production, treatment strategy, Drugs Used to treat Diabetes Mellitus
Definition of hormones
Pancreas
Intro of insulin
Chemistry
Biosynthesis
Action of insulin
Metabolic effect on insulin
Factors effect insulin secretion
Disorders related to insulin hormone
Treatment
Brand name of insulin in market
Insulin is a peptide hormone produced by beta cells of the pancreatic islets, and it is considered to be the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of, especially, glucose from the blood into fat, liver and skeletal muscle cells.
Insulin is a peptide hormone, produced by beta cells of the pancreas, and is central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, skeletal muscles, and fat tissue to absorb glucose from the blood. In the liver and skeletal muscles, glucose is stored as glycogen, and in fat cells (adipocytes) it is stored as triglycerides.
A TRIANGULAR GLAND, WHICH HAS BOTH EXOCRINE AND ENDOCRINE CELLS, LOCATED BEHIND THE STOMACHACINAR CELLS PRODUCE AN ENZYME-RICH JUICE USED FOR DIGESTION (EXOCRINE PRODUCT)PANCREATIC ISLETS (ISLETS OF LANGERHANS) PRODUCE HORMONES INVOLVED IN REGULATING FUEL STORAGE AND USE.
Definition of hormones
Pancreas
Intro of insulin
Chemistry
Biosynthesis
Action of insulin
Metabolic effect on insulin
Factors effect insulin secretion
Disorders related to insulin hormone
Treatment
Brand name of insulin in market
Insulin is a peptide hormone produced by beta cells of the pancreatic islets, and it is considered to be the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of, especially, glucose from the blood into fat, liver and skeletal muscle cells.
Insulin is a peptide hormone, produced by beta cells of the pancreas, and is central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, skeletal muscles, and fat tissue to absorb glucose from the blood. In the liver and skeletal muscles, glucose is stored as glycogen, and in fat cells (adipocytes) it is stored as triglycerides.
A TRIANGULAR GLAND, WHICH HAS BOTH EXOCRINE AND ENDOCRINE CELLS, LOCATED BEHIND THE STOMACHACINAR CELLS PRODUCE AN ENZYME-RICH JUICE USED FOR DIGESTION (EXOCRINE PRODUCT)PANCREATIC ISLETS (ISLETS OF LANGERHANS) PRODUCE HORMONES INVOLVED IN REGULATING FUEL STORAGE AND USE.
Pancreatic hormone - Endocrinology for biochemistryASHA SIVAJI
Pancreatic hormone - In this you will know about synthesis, metabolism, mode of action, biological actions, regulation and disorders related with insulin,Glucagon, Pancreatic somatostatin and pancreatic polypeptide.
Diabetes mellitus (DM):- It is a metabolicdisorder characterized by hyperglycaemia, (fasting plasma glucose ≥ 126 mg/dl and/or ≥ 200 mg/dl 2 hours after 75 g oral glucose),glycosuria, hyperlipidaemia, negative nitrogen balance and sometimes ketonaemia.
Diabetes mellitus, one of the major public health problems worldwide, is a metabolic disorder of multiple etiologies distinguished by a failure of glucose homeostasis with disturbances of carbohydrate, fat and protein metabolism as a result of defects in insulin secretion and/or insulin action.
According to International Diabetes Federation (IDF) report, elevated blood glucose is the third uppermost risk factor for premature mortality, following high blood pressure and tobacco use globally
Cardiovascular diseases, neuropathy, nephropathy, and retinopathy are among the major risks that are associated with diabetes.
These chronic complications may lead to hardening and narrowing of arteries (atherosclerosis) that could advance to stroke, coronary heart disease, and other blood vessel diseases, nerve damage, kidney failure, and blindness with time
Two major types of diabetes mellitus are
1. Insulin-dependent diabetes mellitus (IDDM) / juvenile onset diabetes mellitus
2. Noninsulin-dependent diabetes mellitus (NIDDM) / maturity onset diabetes mellitus
Insulin-dependent diabetes mellitus (IDDM) / juvenile onset diabetes mellitus
There is β cell destruction in pancreatic islets; majority of cases are autoimmune (type 1A) antibodies that destroy β cells are detectable in blood, but some are idiopathic (type 1B)-no βcell antibody is found.
2.Noninsulin-dependent diabetes mellitus (NIDDM) / maturity onset diabetes mellitus
Type 2 diabetes mellitus (T2DM) is the most prevalent metabolic disease worldwide.
There is no loss or moderate reduction in β cell mass: insulin in circulation is low. normal or even high. no anti-β -cell antibody is demonstrable: has a high degree of genetic predisposition: generally has a late onset (past middle age). Over 90% cases of diabetes are type 2 DM
Abnormality in gluco-receptor of β cells so that they respond at higher glucose concentration or relative β cell deficiency. In either way. insulin secretion is impaired: may progress to β cells failure.
Reduced sensitivity of peripheral tissues to insulin: reduction in number of insulin receptors, “down regulation” of insulin receptors.
Excess of hyperglycemic hormones (glucagon, ete. ) obesity: ; cause relative insulin deficiency the β cells Tag behind
Insulin history:
Insulin was discovered in 1921 by Banting and Best who demonstrated the hypoglycaemic action of an extract of pancreas prepared after degeneration of the exocrine part due to ligation of pancreatic duct.
It was first obtained in pure crystalline form in 1926 and the chemical structure was fully worked out in 1956 by Sanger.
Insulin is a two chain polypeptide having 51 amino acids and MW about 6000.
The A-chain has 21 while B-chain has 30 amino acids.
Diabetes mellitus (DM):- It is a metabolicdisorder characterized by hyperglycaemia, (fasting plasma glucose ≥ 126 mg/dl and/or ≥ 200 mg/dl 2 hours after 75 g oral glucose),glycosuria, hyperlipidaemia, negative nitrogen balance and sometimes ketonaemia.
Diabetes mellitus, one of the major public health problems worldwide, is a metabolic disorder of multiple etiologies distinguished by a failure of glucose homeostasis with disturbances of carbohydrate, fat and protein metabolism as a result of defects in insulin secretion and/or insulin action.
According to International Diabetes Federation (IDF) report, elevated blood glucose is the third uppermost risk factor for premature mortality, following high blood pressure and tobacco use globally
Cardiovascular diseases, neuropathy, nephropathy, and retinopathy are among the major risks that are associated with diabetes.
These chronic complications may lead to hardening and narrowing of arteries (atherosclerosis) that could advance to stroke, coronary heart disease, and other blood vessel diseases, nerve damage, kidney failure, and blindness with time
Two major types of diabetes mellitus are
1. Insulin-dependent diabetes mellitus (IDDM) / juvenile onset diabetes mellitus
2. Noninsulin-dependent diabetes mellitus (NIDDM) / maturity onset diabetes mellitus
Insulin-dependent diabetes mellitus (IDDM) / juvenile onset diabetes mellitus
There is β cell destruction in pancreatic islets; majority of cases are autoimmune (type 1A) antibodies that destroy β cells are detectable in blood, but some are idiopathic (type 1B)-no βcell antibody is found.
2.Noninsulin-dependent diabetes mellitus (NIDDM) / maturity onset diabetes mellitus
Type 2 diabetes mellitus (T2DM) is the most prevalent metabolic disease worldwide.
There is no loss or moderate reduction in β cell mass: insulin in circulation is low. normal or even high. no anti-β -cell antibody is demonstrable: has a high degree of genetic predisposition: generally has a late onset (past middle age). Over 90% cases of diabetes are type 2 DM
Abnormality in gluco-receptor of β cells so that they respond at higher glucose concentration or relative β cell deficiency. In either way. insulin secretion is impaired: may progress to β cells failure.
Reduced sensitivity of peripheral tissues to insulin: reduction in number of insulin receptors, “down regulation” of insulin receptors.
Insulin history:
Insulin was discovered in 1921 by Banting and Best who demonstrated the hypoglycaemic action of an extract of pancreas prepared after degeneration of the exocrine part due to ligation of pancreatic duct.
It was first obtained in pure crystalline form in 1926 and the chemical structure was fully worked out in 1956 by Sanger.
Insulin is a two chain polypeptide having 51 amino acids and MW about 6000.
The A-chain has 21 while B-chain has 30 amino acids.
Insulin is synthesized in the β cells of pancreatic islets as a single chain peptide Preproinsulin (110 AA) from whic
Diabetes mellitus (DM):- It is a metabolicdisorder characterized by hyperglycaemia, (fasting plasma glucose ≥ 126 mg/dl and/or ≥ 200 mg/dl 2 hours after 75 g oral glucose),glycosuria, hyperlipidaemia, negative nitrogen balance and sometimes ketonaemia.
Diabetes mellitus, one of the major public health problems worldwide, is a metabolic disorder of multiple etiologies distinguished by a failure of glucose homeostasis with disturbances of carbohydrate, fat and protein metabolism as a result of defects in insulin secretion and/or insulin action.
According to International Diabetes Federation (IDF) report, elevated blood glucose is the third uppermost risk factor for premature mortality, following high blood pressure and tobacco use globally
Cardiovascular diseases, neuropathy, nephropathy, and retinopathy are among the major risks that are associated with diabetes.These chronic complications may lead to hardening and narrowing of arteries (atherosclerosis) that could advance to stroke, coronary heart disease, and other blood vessel diseases, nerve damage, kidney failure, and blindness with time
Two major types of diabetes mellitus are
1. Insulin-dependent diabetes mellitus (IDDM) / juvenile onset diabetes mellitus
2. Noninsulin-dependent diabetes mellitus (NIDDM) / maturity onset diabetes mellitus
Insulin-dependent diabetes mellitus (IDDM) / juvenile onset diabetes mellitus
There is β cell destruction in pancreatic islets; majority of cases are autoimmune (type 1A) antibodies that destroy β cells are detectable in blood, but some are idiopathic (type 1B)-no βcell antibody is found.
2.Noninsulin-dependent diabetes mellitus (NIDDM) / maturity onset diabetes mellitus
Type 2 diabetes mellitus (T2DM) is the most prevalent metabolic disease worldwide.
There is no loss or moderate reduction in β cell mass: insulin in circulation is low. normal or even high. no anti-β -cell antibody is demonstrable: has a high degree of genetic predisposition: generally has a late onset (past middle age). Over 90% cases of diabetes are type 2 DM
Abnormality in gluco-receptor of β cells so that they respond at higher glucose concentration or relative β cell deficiency. In either way. insulin secretion is impaired: may progress to β cells failure.
Reduced sensitivity of peripheral tissues to insulin: reduction in number of insulin receptors, “down regulation” of insulin receptors.
Insulin history:
Insulin was discovered in 1921 by Banting and Best who demonstrated the hypoglycaemic action of an extract of pancreas prepared after degeneration of the exocrine part due to ligation of pancreatic duct.
It was first obtained in pure crystalline form in 1926 and the chemical structure was fully worked out in 1956 by Sanger.
Insulin is a two chain polypeptide having 51 amino acids and MW about 6000.
The A-chain has 21 while B-chain has 30 amino acids.
Insulin is synthesized in the β cells of pancreatic islets as a single chain peptide Preproinsulin (110 AA) from which
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
2. INTRODUCTION
• Diabetes mellitus is a metabolic disorder characterised by hyperglycaemia,
glycosuria, hyperlipidaemia, negative nitrogen balance and sometimes
ketonemia.
• Lack of Insulin affects the metabolism of carbohydrate, protein and fat.
• The major types of diabetes mellitus are:-
1) Type I (insulin dependent diabetes mellitus):
It appears when more than 90% of ß cells of pancreas are destroyed by an
autoimmune process.
Autoimmune (type I A) antibodies that destroyed ß cells are detectable in blood,
but some are idiopathic (type I B), no ß cell antibody is found.
There is insulin deficiency and patient are more prone to ketosis.
Insulin is essential for all patients with type I diabetes mellitus.
This type is less common and has a low degree of genetic predisposition.
3. 2) Type II ( Non insulin dependent diabetes mellitus)
Genetic influence is much more powerful in type II diabetes mellitus. It is commonest
form of diabetes.
Overeating, obesity, underactivity and ageing are the main risk factors.
It is associated with increased hepatic production of glucose and resistance of target
tissue to the action of insulin.
• There are four types of cells in islets of Langerhans of pancreas:
• 1) β cells- secrete insulin.
• 2) ⍺ cells- secrete glucagon.
• 3) δ cells- secrete somatostatin.
• 4) follicular cells- secrete pancreatic polypeptide.
4. INSULIN:
Introduction:
Insulin was discovered by Banting and Best.
It is primary hormone which is responsible for controlling the storage and
utilization of cellular nutrients.
Insulin is a two chain polypeptide having 51 amino acids and molecular
weight about 6000.
It has two amino acid chains called α and β chains, which are linked by
disulfide bridges. The α-chain of insulin contains 21 amino acids and β-
chain contains 30 amino acids.
The biological half-life of insulin is 5 minutes.
Insulin activates the transport system and the enzymes involved in the
intra cellular utilization and storage of glucose, amino acids and fatty acids.
Insulin inhibit catabolic processes such as breakdown of glycogen, fat and
protein.
Deficiency of effective insulin in the body cause diabetes mellitus, which
alter the metabolism of lipids, carbohydrate and proteins.
5. Structure:
fig: Insulin molecule
Insulin molecule is consist of two peptide chains, A chain and B chain, which are
connected by disulphide bond. The chain A is composed of 21 amino acid residues starting from Gly
and end to Asn. It has one intrachain disulphide bond in between 6th and 11th molecule of chain.
The chain B has 30 amino acid residue starting from Phe & end on Thr. The molecule weight is
about 6000.
The crystal structure also reveals that the two chains of the hormones from a highly
ordered structure with several ⍺- helical regions in both the chains. The carboxyl terminal portion of the
B chain and the amino and carboxyl terminal residue of the A chain from the surface of the molecules which
interact with the receptor.
6. • The insulin receptor is a large transmembrane glycoprotein composed of two ⍺
subunits and two β subunits. The subunits are linked by disulphide bonds to form β-⍺-⍺-β
hetro-tetramer.
Biosynthesis of insulin:
• Insulin is produced by the β- cells of the islets of Langerhans of pancreas.
• The gene for this protein synthesis is located on chromosome 11.
• The synthesis of insulin involves two precursors namely preproinsulin with 108 amino acid
and proinsulin with 86 amino acid. They are sequentially degraded to form the active
hormone insulin and a connecting peptide ( c- peptide).
• Insulin and c- peptide are produced in equimolar concentration.
• C- peptide has no biological activities but its estimation in the plasma serves as a useful
index for the endogenous production of the insulin.
• In the β cells, Insulin and also proinsulin combines with zinc to form complexes. In this
form insulin is stored in the granules of the cytosol, which is released in response to
various stimuli by exocytosis.
• Insulin circulates in blood as a free monomer.
7. Regulation of insulin secretion:
• About 40-50 units of insulin (1- 2 mg) is secreted daily by human pancreas.
• The normal insulin concentration in plasma is 20-30 μU/ml.
• The important factors that influence the release of insulin from the β cells of pancreas are-
1) Factors stimulating insulin secretion:
a) Glucose: A rise in blood glucose level is a signal for insulin secretion.
b) Amino acids: protein rich meal cause transient rise in plasma amino acid
concentration. Argenine and leucine are potent stimulator of insulin release.
C) GI hormones: secretin, gastrin, pancreozymin enhance the secretion of insulin.
2) Factors inhibit insulin secretion:
Epinephrine is the most potent inhibitor of insulin release.
In emergency situations like stress, extreme exercise and trauma, the nervous system
stimulate adrenal medulla to release epinephrine. Epinephrine supress insulin release
and promotes energy metabolism by mobilizing energy yielding compounds glucose from
liver and fatty acid from adipose tissue.
8. Degradation of Insulin:
• Insulin has a normal half life of 4 to 5 min. A protease enzyme, insulinase (mainly
found in liver and kidney) degrades insulin.
Mechanism of action of insulin:
Insulin binds to specific plasma membrane receptors present on the target
tissue, such as muscle and adipose. There are 3 distinct mechanism of insulin action:
1) The induction of transmembrane signals:
The insulin receptor is synthesized as a single polypeptide and cleaved to ⍺ and
β subunits. The insulin receptor has a half life of 6- 12 hours. As the hormone insulin binds to
the receptor, a conformational change is induced in ⍺ subunits. This result in generation of
signals which are transduce to β subunit. As a result the insulin binding activates tyrosine kinase
activity. This cause the autophosphorylation of tyrosine residue on β subunit. Tyrosine kinase
also phosphorylate insulin receptor substrate, this promotes activation of other protein kinase
and phosphatase, finally leading to biological actions.
9. 2) Insulin mediated glucose transport:
The binding of insulin to insulin receptor signals, the translocation of vesicles containing
glucose transporters from intracellular pool to the plasma membrane.
Official Drugs:
1. Insulin (I.P., B.P.)-
- Obtained from beef or pork pancreases and purified.
- White or almost white powder.
- Insoluble in water practically.
- Kept in air tight container, protect form light & stored at cold temperature.
2. Insulin Injection-
- Available as sterile, acidified or neutral solution of bovine, porcine or human insulin in
water for injection containing 40, 80, 100 or 500 USP insulin units per ml.
- It is colourless, free from turbidity and foreign matter.
10. 3. Lipro / human insulin-
-It is a human insulin analogue of rDNA origin synthesis from a
special non-pathogenic strain of E. coli genetically altered by addition of the
gene for insulin lispro; Lys (B28), pro (B29)
-It is a very rapid acting insulin, injected just prior to a meal.