Calcitonin

1. APOLLO COLLAGE OF PHARMACY , DURG
ANJORA (2023 -2024)

2. CALCITONIN
 Guided by
MR. Hari Prasad Sonwani
 PRESANTATED BY
Tejashwani sinha, kalpna, Kuldeep sahu, Kavita

3. Introduction
 Calcitonin is a hormone that your thyroid gland makes and releases to help
regulate calcium levels in your blood by decreasing it. Calcitonin opposes the
actions of the parathyroid hormone, which is a hormone that increases your
blood calcium levels.
Defination of calcitonin
 The C-cells in your thyroid (parafollicular cells) make and secrete
calcitonin.

4.  Calcium is one of the most important and common minerals in
your body. Your body stores most of your calcium in your
bones, but you have and need it in your blood as well. The
calcium in your blood has many important roles, including
•Helping your nerves work.
•Helping your blood clot if you’re bleeding.
•Helping your heart work properly.

5. Important of caicitonin regulation
 Calcitonin is a hormone that plays a crucial role in
regulating calcium levels in the body. It helps lower blood
calcium levels by inhibiting bone breakdown and enhancing
calcium excretion by the kidneys. Proper regulation of
calcitonin is essential for maintaining bone health and
preventing conditions like osteoporosis. It also contributes
to overall calcium homeostasis, ensuring optimal nerve and
muscle function. Imbalances in calcitonin regulation can
lead to disorders affecting bone density and calcium
metabolism.

7. Structure of calcitonin
 Calcitonin is a peptide hormone involved in calcium and phosphate
homeostasis. Its structure consists of 32 amino acids, forming a single chain
with a disulfide bridge between two cysteine residues. The molecular structure
includes an N-terminal region, which is the active site responsible for its
physiological effects, and a C-terminal region. Calcitonin is produced by the
parafollicular cells (C cells) of the thyroid gland and functions to reduce blood
calcium levels by inhibiting osteoclast activity in bones.
Moleculer structure of calcitonin

9. Chemical composition of calcitonin
 Calcitonin's chemical composition involves a chain of amino acids linked together by
peptide bonds. The specific sequence of amino acids determines its unique structure
and biological function. The primary structure of calcitonin, representing the linear
arrangement of amino acids, is crucial for its activity in regulating calcium
metabolism.
 The chemical formula for a peptide is often denoted by the sequence of its constituent
amino acids. In the case of calcitonin, the sequence of the 32 amino acids in the
peptide chain forms its chemical composition. Each amino acid has a distinct side
chain, and the overall arrangement contributes to the three-dimensional structure of
the molecu

10. Synthesis of calcitonin
 The synthesis of calcitonin involves the production of the peptide hormone
in living organisms, typically in the thyroid gland. Here's a simplified
overview of the synthesis process:
1. Gene Expression: The genetic information for calcitonin is encoded in DNA.
The gene responsible for calcitonin production is transcribed into messenger
RNA (mRNA).
2. Translation: The mRNA moves to the ribosomes, where it acts as a template
for the synthesis of a chain of amino acids, forming the primary structure of
the calcitonin peptide.

11. 3. Post-translational Modifications: The newly formed peptide may undergo
post-translational modifications. These modifications can include glycosylation
or other chemical alterations, which can impact the stability and activity of
calcitonin.
4. Folding and Maturation: The peptide undergoes proper folding into its three-
dimensional structure. This process may occur in the endoplasmic reticulum
and Golgi apparatus, where additional modifications and maturation steps take
place.
5. Packaging into Vesicles: The mature calcitonin is packaged into vesicles
within the cells of the thyroid gland.

12. 6. Release: Upon stimulation, these vesicles containing
calcitonin fuse with the cell membrane, releasing calcitonin into
the bloodstream.
It's important to note that calcitonin is produced by the
parafollicular cells, also known as C cells, in the thyroid gland.
The release of calcitonin is often stimulated by high levels of
blood calcium, and its primary function is to regulate calcium
and phosphate levels in the body by inhibiting bone resorption
and promoting calcium excretion by the kidney

14. Secretion of calcitonin
.
 The secretion of calcitonin is regulated by the parafollicular cells (also known as C cells) in
the thyroid gland. These cells monitor the levels of calcium in the blood and release
calcitonin in response to elevated calcium levels. Here's a simplified overview of the
secretion process:
1. Detection of High Blood Calcium Levels: When blood calcium levels rise, the
parafollicular cells in the thyroid gland sense this increase.
2. Stimulation of Parafollicular Cells: Elevated blood calcium levels stimulate the
parafollicular cells to produce and release calcitonin.
3. Calcitonin Synthesis: Inside the parafollicular cells, calcitonin is synthesized. This
involves the transcription of the calcitonin gene into messenger RNA (mRNA), translation of
mRNA into a chain of amino acids, and post-translational modifications to form the mature
calcitonin peptide.

15. 4. Packaging into Vesicles: The synthesized and mature calcitonin is packaged
into secretory vesicles within the parafollicular cells.
5. Release of Calcitonin: The secretory vesicles containing calcitonin are
released from the parafollicular cells. This release can be triggered by various
stimuli, including hormonal signals or neural input.
6. Transport in Bloodstream: Calcitonin is released into the bloodstream, where
it can travel to target tissues, primarily the bones and kidneys.
7. Effects on Target Tissues: Calcitonin acts on bone cells (osteoclasts) to inhibit
bone resorption, reducing the breakdown of bone tissue. Additionally, it
enhances the excretion of calcium by the kidneys, further lowering blood
calcium levels.

16. 8. Negative Feedback: The reduction in blood calcium levels serves as a
negative feedback mechanism. As calcium levels return to normal, the
stimulus for calcitonin release diminishes, regulating the overall calcium
balance.
This process helps maintain homeostasis by counteracting the effects of
parathyroid hormone (PTH), which raises blood calcium levels. Together,
calcitonin and PTH contribute to the finely tuned regulation of calcium levels
in the body.

17. Function of calcitonin
1. Inhibition of Osteoclast Activity: Calcitonin acts on osteoclasts, which
are cells responsible for breaking down bone tissue. It inhibits osteoclast
activity, reducing bone resorption.
2. Decreased Calcium Release: By suppressing osteoclasts, calcitonin
helps to decrease the release of calcium from bones into the
bloodstream. This is especially important in maintaining appropriate
calcium levels in the blood.
3. Lowered Blood Calcium Levels: The primary effect of calcitonin is to
lower blood calcium levels. It opposes the action of parathyroid hormone
(PTH), which increases blood calcium levels by stimulating osteoclasts.

18. 4. Enhanced Calcium Deposition: Calcitonin promotes the deposition of
calcium and phosphate in the bones, contributing to bone formation
and mineralization.
5. Role in Calcium Homeostasis: Alongside other hormones, such as PTH,
calcitonin plays a crucial role in maintaining calcium homeostasis – the
balance of calcium levels in the body.
6. Limited Impact on Normal Calcium Regulation: While calcitonin is
involved in calcium regulation, its influence is generally considered less
significant compared to PTH. PTH has a more substantial effect on
increasing blood calcium levels.

19. 7. Response to High Blood Calcium Levels: Calcitonin
secretion is triggered when blood calcium levels are
elevated. Its release helps counteract the excess
calcium by promoting its storage in bone tissue.

21. Target tissuses
Calcitonin primarily acts on bone tissue and the kidneys. Its physiological effects
are aimed at regulating calcium homeostasis in the body.
1. Bone Tissue:
- Inhibition of Osteoclast Activity: Calcitonin works to inhibit the activity of
osteoclasts, cells responsible for breaking down bone tissue. By doing so, it helps
prevent the release of calcium from bones into the bloodstream.
- Promotion of Calcium Deposition: Calcitonin promotes the deposition of
calcium into bones. This encourages the storage of calcium within the bone
matrix, contributing to bone density and strength.
2. Kidneys:
- Decreased Calcium Reabsorption: Calcitonin can reduce the reabsorption of
calcium by the kidneys. This results in increased excretion of calcium in the urine,
further aiding in lowering blood calcium levels.

23. Clinical relevance
The clinical relevance of calcitonin lies in its role as a hormone involved in calcium
homeostasis and bone metabolism.
One medical condition related to calcitonin is "medullary thyroid carcinoma"
(MTC). MTC is a rare type of thyroid cancer that originates from the parafollicular
cells, also known as C cells, in the thyroid gland. These are the same cells that
produce calcitonin.
In medullary thyroid carcinoma:
1. Overproduction of Calcitonin: MTC is associated with the excessive production
of calcitonin by the C cells. Elevated levels of calcitonin in the bloodstream can
be a marker used in diagnosing and monitoring the progression of MTC.
2. Tumor Formation: MTC usually presents as a tumor in the thyroid gland, and in
some cases, it may spread to other parts of the body.
3. Genetic Component: In some cases, MTC can be hereditary and associated with
multiple endocrine neoplasia (MEN) syndromes.

24. Research and discovery related
to calcitonin
Research related to calcitonin covers various aspects, including its physiological roles,
clinical applications, and potential therapeutic interventions. Here are a few key areas of
ongoing research related to calcitonin:
1. Osteoporosis Treatment:
- Researchers are exploring the effectiveness of calcitonin and its derivatives in the
treatment of osteoporosis. Investigating their impact on bone metabolism and density is of
interest in developing alternative or complementary therapies.
2. Calcitonin in Cancer Research:
- Studies continue to examine the role of calcitonin in cancers, particularly in medullary
thyroid carcinoma (MTC). Researchers aim to understand the molecular mechanisms
involved in MTC development and identify potential therapeutic targets.
3. Neuroprotective Effects:
- Some research suggests that calcitonin may have neuroprotective effects, potentially
offering benefits in neurodegenerative conditions. Investigations are ongoing to explore its
impact on neuronal health and its potential use in neurological disorders.

25. 4. Calcitonin and Pain Management:
- There is ongoing research into the analgesic (pain-relieving)
properties of calcitonin. Studies explore its role in managing various
types of pain, including chronic pain conditions, and its potential as an
adjunct therapy in pain management.
5. Calcitonin Gene-Related Peptide (CGRP):
- CGRP, a peptide closely related to calcitonin, is a focus of research in
migraine treatment. Investigating the role of CGRP and its receptors in
migraines has led to the development of medications targeting the CGRP
pathway.
6. Biomarker Discovery:
- Researchers are working on identifying additional roles of calcitonin
as a biomarker in various diseases beyond thyroid cancer. Exploring its
significance in other medical conditions may enhance diagnostic
capabilities.

26. conclusion
In conclusion, our exploration of calcitonin reveals its pivotal role in
calcium homeostasis and bone metabolism. While primarily associated
with the thyroid gland, calcitonin's influence extends beyond, impacting
crucial physiological processes.
From its contribution to bone health by inhibiting osteoclast activity to
its significance as a biomarker in medullary thyroid carcinoma, calcitonin
plays a diverse role in maintaining overall well-being. Ongoing research
opens new avenues, such as its potential in osteoporosis treatment,
neuroprotective effects, and pain management.

27. References
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(CT)". Endocrinology: hormonal control of calcium and phosphate. Medical
College of Georgia. Archived from the original on September 5, 2008.
Retrieved 2008-08-07.
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