The document summarizes male gonadal hormones and testosterone synthesis. It discusses how testosterone is produced in the testes by Leydig cells from cholesterol. The key steps involve conversion to pregnenolone and downstream intermediates until formation of testosterone. Testosterone can be further metabolized to the more potent dihydrotestosterone in target tissues like the prostate. Testosterone regulates male sexual development and maintenance of secondary sex characteristics and has important effects on muscle, bone, and brain.
What is sex hormone ?
Sex hormones are synthesized from cholesterol and secreted throughout a person's lifetime
at different levels.
Male gonads (testes) produce sperm.
Female gonads (ovaries) produce egg.
Fusion of egg and sperm occur via fertilization to produce a zygote.
The zygote undergoes division to become an embryo, which eventually becomes a fetus.
Đối với phụ nữ, nội tiết tố nữ được ví như nhựa sống cho cơ thể. Khi tình trạng mất cân bằng nội tiết tố xuất hiện có thể gây ra những ảnh hưởng lớn đối với cơ thể. Để hiểu rõ về nội tiết tố là gì, tác dụng ra sao, nguyên nhân gây mất cân bằng cách điều trị hiệu quả hãy cùng tham khảo bài viết sau.
Nguồn: Trích https://venusglobal.com.vn/noi-tiet-to-nu/
#nội_tiết_tố_nữ
#điều_trị_rối_loạn_nội_tiết_tố_nữ
#thuốc_điều_trị_rối_loạn_nội_tiết_tố_nữ
#cách_điều_trị_rối_loạn_nội_tiết_tố_nữ
#cách_chữa_rối_loạn_nội_tiết_ở_nữ
Medicinal Chemistry of Steroidal Harmons
Classification of Steroidal Harmons
Medicinal Uses
Biosynthesis of Steroidal Harmons
Mechanism of action of Steroidal Harmons
Natural and Synthetic derivatives of Steroidal Harmons and their Inhibitors
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
What is sex hormone ?
Sex hormones are synthesized from cholesterol and secreted throughout a person's lifetime
at different levels.
Male gonads (testes) produce sperm.
Female gonads (ovaries) produce egg.
Fusion of egg and sperm occur via fertilization to produce a zygote.
The zygote undergoes division to become an embryo, which eventually becomes a fetus.
Đối với phụ nữ, nội tiết tố nữ được ví như nhựa sống cho cơ thể. Khi tình trạng mất cân bằng nội tiết tố xuất hiện có thể gây ra những ảnh hưởng lớn đối với cơ thể. Để hiểu rõ về nội tiết tố là gì, tác dụng ra sao, nguyên nhân gây mất cân bằng cách điều trị hiệu quả hãy cùng tham khảo bài viết sau.
Nguồn: Trích https://venusglobal.com.vn/noi-tiet-to-nu/
#nội_tiết_tố_nữ
#điều_trị_rối_loạn_nội_tiết_tố_nữ
#thuốc_điều_trị_rối_loạn_nội_tiết_tố_nữ
#cách_điều_trị_rối_loạn_nội_tiết_tố_nữ
#cách_chữa_rối_loạn_nội_tiết_ở_nữ
Medicinal Chemistry of Steroidal Harmons
Classification of Steroidal Harmons
Medicinal Uses
Biosynthesis of Steroidal Harmons
Mechanism of action of Steroidal Harmons
Natural and Synthetic derivatives of Steroidal Harmons and their Inhibitors
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2. LEARNING OBJECTIVES
Identify the type of hormones involve in testicular steroidogenesis and their
origin
Illustrate the pathway of formation of male sex hormones and factors
controlling them
Discuss mode of action of hormone
Explain the pathological consequences due to biosynthetic defects
3. HORMONES
3
◎ hormone is a substance that is synthesized in one organ and transported by
the circulatory system to act on another tissue
◎ hormones can act on adjacent cells (paracrine action) and on the cell in
which they were synthesized (autocrine action) without entering the
systemic circulation
4. 4
GONADAL HORMONES
- Produced by the human gonads: the testis and ovaries
- The primary hormones produced by these organs include:
Androgens: testosterone
Estrogens
progestins
- Part of the hypothalamic –pituitary-gonadal axis
- Regulated by pituitary hormones: FSH and LH (regulated by your GnRH:
hypothalamus)
5. GONADS
◎ Bifunctional – produce:
1. GERM CELLS, AND
2. SEX HORMONES
◎ OVARIES – produce:
1. Ova, and
2. Estrogen and Progesterone
◎ TESTES – produce:
1. Spermatozoa, and
2. Testosterone
6. 6
Paired, ovoid organs serve dual functions
Production of sperm
Production of reproductive steroid hormones
Functional Anatomy of the Male reproductive tract
Testes are located outside the body encased by a muscular sac
Blood flow and contraction of dartos muscle regulate temperature of
testicles to 2 C below core body temperature, which is vital to sperm
production
THE TESTES
7. 7
◎ Sperm develop within the seminiferous
tubules of the testes
◎ The tubules include 2 primary sex cord-
stromal cells
○ Leydig cells – testosterone
○ Sertoli cells- inner lining of the tubules
10. 10
• Spermatic cord can retract testicles into inguinal canal when
injury is threatened
• Composed of 2 anatomic units:
Seminiferous tubules: contain germ and sertoli cells
Interstitium: leydig cells
11. 11
• Physiology of the testicles
• Spermatogenesis
spermatogonia: stem cells that form
sperm
• Undergo mitosis and meiosis; haploid
cells transform to form mature sperm
• Mature sperm has head, body, and tail
so it can swim
20. Steroid Synthesis - Cholesterol to
Precursors)
A. Cholesterol converted to Pregnenolone
1. Stimulated by ACTH release from
anterior pituitary
2. Key enzyme: Cholesterol Desmolase
(Cholesterol Side chain cleavage
enzyme)
B.Pregnenolone converted to Progesterone
1. Pregnenolone is precursor of all steroids
2. Key enzyme: 3-B-Hydroxysteroid
Dehydrogenase
21. Steroid Synthesis - Cholesterol to Precursors
C. Progesterone converted to 17-a-
hydroxyprogesterone
1. Key enzyme: 17-Hydroxylase
2. 17-a-hydroxyprogesterone is precursor
1. Cortisol Synthesis
2. Aldosterone Synthesis
D. 17-a-hydroxyprogesterone converted
to Androstenedione
1. Key enzyme: 3-B-Hydroxysteroid
Dehydrogenase
2. Androstenedione is sex Hormone precursor
1. Estrone
2. Testosterone
3. Estradiol
22. Sex Hormones from Androstenedione
A. Androstenedione converted to Estrone
Key enzyme: Aromatase
B. Androstenedione converted to Testosterone
Key enzyme: 17 B hydroxysteroid
dehydrogenase
1. Testosterone converted to Estradiol
23. HOW IS TESTOSTERONE SYNTHESIZED?
◎ Synthesized by the LEYDIG CELLS
◎ CHOLESTEROL – immediate precursor
◎ RATE LIMITING STEP – delivery of
cholesterol to mitochondria by the
protein StAR (steroidogenic acute
regulatory protein)
◎ Cytochrome P450 side chain cleavage
(P450scc) enzyme - conversion of
CHOLESTEROL to PREGNENOLONE
24. HOW IS TESTOSTERONE SYNTHESIZED?
The conversion of pregnenolone to testosterone requires 5
enzyme activities contained in 3 proteins:
1. 3β-hydroxysteroid dehydrogenase (3β-OHSD) and Δ5,4-isomerase;
2. 17α-hydroxylase and 17,20-lyase;
3. 17β-hydroxysteroid dehydrogenase (17β-OHSD)
25. HOW IS TESTOSTERONE SYNTHESIZED?
2 PATHWAYS:
1. DEHYDROEPIANDROSTERONE PATHWAY
2. PROGESTERONE PATHWAY
31. How is Testosterone metabolized?
1
2
3
4
5
6
7
8
9
1
0
1
9
1
1
1
2
1
3
1
4 1
5
1
6
1
7
1
8
2 pathways:
1. oxidation at 17 position, and
2. reduction of the A ring double bond and the 3
ketone
A
32. How is Testosterone metabolized?
1
2
3
4
5
6
7
8
9
10
19
11
12
13
14
15
16
17
18
◎ First pathway
○ occurs in many tissues (liver)
○ produces less active compounds
33. How is Testosterone metabolized?
1
2
3
4
5
6
7
8
9
10
19
11
12
13
14
15
16
17
18
◎ Second pathway
○ occurs in target tissues
○ less efficient
○ produces the potent metabolite DHT (DIHYDROTESTOSTERONE)
A
34. How is Testosterone metabolized?
◎ Testosterone is as prohormone
◎ It is converted to more potent DHT
A
35. First Pathway Second Pathway
More efficient Less efficient
Produces less potent
metabolite:
17 ketosteroids
Produces potent metabolite:
Dehydrotestosterone (DHT)
Occurs in many tissues like
liver
Occurs in target tissues
37. Dihydrotestosterone (DHT)
◎ The most significant metabolic product of testosterone
◎ Target cells (Highest α reductase activity):
○ Prostate
○ External genitalia
○ Some areas of the skin (genital skin)
38. Dihydrotestosterone (DHT)
◎ Produced ∼400 μg/day
○ compared with 5 mg of testosterone.
○ 50-100 μg – secreted by the testes.
○ The rest – peripherally from testosterone
42. After birth, testes make
only androsterone
(inactive sex hormone)
Ability to produce
testosterone is restored
at puberty and
continues throughout
life
43. REGULATION OF TESTICULAR FUNCTION
Testicular steroidogenesis is
stimulated by lutenizing
hormone and activating adenylyl
cyclase and increasing cAMP
44.
45. Effects of testosterone and other androgens
45
Testosterone and other androgens are responsible for the development of both
primary and secondary male sex characteristics
Stimulates growth of the male reproductive organs
o Enlargement of the penis, testes and scrotum
o Duct and glandular development of the male RS
Stimulates spermatogenesis; without testosterone males become sterile
46. 46
Stimulates the development of secondary sex characteristics
o Androgenic hair (pubic, axillary and facial hairs
o Dermatologic changes :
o skin becomes darker and thicker
o Increase sebum secretion: can lead to acne
o Increase apocrine sweat glands
o Growth of the larynx- deepening of the voice
Musculoskeletal effect:
o Increase bone growth
o Increase muscle mass
o Increase connective tissue
47. Clinical Correlation:
◎ HYPOGONADISM
○ lack of testosterone synthesis
◎ TESTICULAR FEMINIZATION SYNDROME
○ genetically male but lack functional
receptors—feminization of external
genitalia
hormone is a substance that is synthesized in one organ and transported by
the circulatory system to act on another tissue. However, this original
description is too restrictive because hormones can act on adjacent cells
(paracrine action) and on the cell in which they were synthesized
(autocrine action) without entering the systemic circulation
Anatomy of the testis and seminiferous tubules. Note the tubules are created by sertoli cells surrounded by the leydig cells Spermatogenesis takes place within the seminiferous tubules
Spermatogenesis is the process of sperm cell formation, development and maturation
This diagram shows a single seminiferous tubule, and cells in the interstitial tissue outside the tubule. In this connective tissue between the seminiferous tubules there are large cells with eosinophilllic cytoplasm called Leydig cells.
There are also cells called myoid cells surrounding the basement membrane, which are squamous contractile cells, and generate peristaltic waves in the tubules.
All of the gonadal hormones are steroids produced from cholesterol via a series of enzymatic steps
Steroidogenesis process by which some cells can manufacture steroids such as aldosterone, estradiol, testosterone from the parent steroid known as cholesterol. Cholesterol has variety of functions like stabilizing cell membranes over a wide range of temperatures and it is also used in manufacture of bile acids for emulsification of fats… and the most impt function of cholesterol is the conversion of all these steroids shown in this diagram
Yellow – progestagensblue- androgens
Pink – estrogens
Green glucocorticoids
Purple- mineralocorticods: aldosteronered: mitochondrial enzymesgreen: microsomal enzymes : embedded in the membrane of SER
Side chain cleavage enzyme (also known as cholesterol desmolase) is a cytochrome P450 enzyme encoded by the CYP11A1 gene located at chromosome 15q23-q24. This enzyme converts cholesterol to pregnenolone
Testicular androgens are synthesized in the interstitial tissue by the Leydig cells.
The immediate precursor of the gonadal steroids, as for the adrenal steroids, is cholesterol.
The rate-limiting step, as in the adrenal, is delivery of cholesterol to the inner membrane of the mitochondria by the transport protein
StAR. Once in the proper location, cholesterol is acted upon by the side chain cleavage enzyme P450scc. The conversion of cholesterol to pregnenolone is identical in adrenal, ovary, and testis. In the latter two tissues, however, the reaction is promoted by LH rather than ACTH.
The conversion of pregnenolone to testosterone requires the action of five enzyme activities contained in three proteins: (1) 3β-hydroxysteroid dehydrogenase (3β-OHSD) and Δ5,4-isomerase; (2) 17α-hydroxylase and 17,20-lyase; and (3) 17β-hydroxysteroid dehydrogenase (17β-OHSD).
This sequence, referred to as the progesterone (or Δ4) pathway, is shown on the right side of Figure 41–5. Pregnenolone can also be converted to testosterone by the dehydroepiandrosterone (or Δ5) pathway, which is illustrated on the left side of Figure 41–5. The Δ5 route appears to be most used in human testes.
The gonadal hormones particularly the testosterone are lipophilic, so they must be protein bound to travel in the blood. In general, they are bound to SHBG 40%
Testosterone is metabolized by two pathways. One involves oxidation at the 17 position, and the other involves reduction of the A ring double bond and the 3-ketone.
oxidation at 17 position
Metabolism by the second pathway, which is less efficient, occurs primarily in target tissues (Prostate, External genitalia, Some areas of the skin
produces the potent metabolite DHT.
reduction of the A ring double bond and the 3 ketone.
DHT: Dihydrotestosterone
Testosterone can thus be considered a prohormone since it is converted into a much more potent compound (DHT) and since most of this conversion occurs outside the testes.
2 pathways:
oxidation at 17 position, and
reduction of the A ring double bond and the 3 ketone
The most significant metabolic product of testosterone is DHT, since in many tissues, including prostate, external genitalia, and some areas of the skin, this is the active form of the hormone.
The plasma content of DHT in the adult male is about one-tenth that of testosterone, and ∼400 μg of DHT is produced daily as compared with about 5 mg of testosterone. About 50 to 100 μg of DHT are secreted by the testes. The rest is produced peripherally from testosterone in a reaction catalyzed by the NADPH-dependent 5α-reductase (Figure 41–6).
Some estradiol is formed from the peripheral aromatization of testosterone, particularly in males.
This is the hypothalamic-Pituitary-testicular axisPreoptic neurons in the hypothalamus secretes GnRHGnRH stimulates the anterior pituitary to release LH and FSHLH and FSH stimulate cells in the testes: LH primarily affects the testicular Leydig cells – stimulates the production of testosteroneFSH primarily affects the testicular Sertoli cells which stimulates spermatogenesis and synthesizes regulatory peptides (including inhibin) and various growth factorsFeedback and regulation of the HPT axisTestosterone inhibits secretion of GNRH, FSH and LHInhibin selectively inhibits FSH