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1. Hormonal Regulation of
Metabolic Processes
Presentation : Bio-chemistry
Kiran (F23-0940)
RuqqiaBibi (F23-0942)
LaibaHameed (F23-0941)
Muhammad Ahmad (F23-0943)

2. oKiran (F23-0940)
Topic :
Introduction to Hormonal Regulation of
Metabolic Processes
Hormones play a crucial role in the regulation of metabolic processes in the
body. These biochemical messengers are produced by various glands and
organs and act on specific target tissues to regulate numerous physiological
activities. The interplay of hormones ensures that the body maintains
homeostasis, responding dynamically to changes in internal and external
environments.

3. Key Hormones and Their Functions in
Metabolic Regulation:
1. Insulin
: Produced by the pancreas, insulin facilitates the uptake of glucose
by cells, promoting glycogen synthesis and inhibiting gluconeogenesis,
thus lowering blood glucose levels.
2. Glucagon
: Also produced by the pancreas, glucagon counteracts insulin by
stimulating glycogen breakdown and gluconeogenesis in the liver, thereby raising blood glucose levels.
3. Thyroid
Hormones (T3 and T4): Secreted by the thyroid gland, these
hormones increase the basal metabolic rate, enhance protein synthesis, and sensitize the body to catecholamines, thereby regulating overall energy expenditure.
4. Cortisol
: Produced by the adrenal cortex, cortisol increases blood glucose
levels through gluconeogenesis and plays a vital role in the metabolism of fats, proteins, and carbohydrates, as well as in the body's stress response.

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4. Cortisol: Produced by the adrenal cortex, cortisol increases blood glucose levels
through gluconeogenesis and plays a vital role in the metabolism of fats, proteins,
and carbohydrates, as well as in the body's stress response.
5. Catecholamines (Epinephrine and Norepinephrine):
Released by the adrenal
medulla, these hormones increase metabolic rate and blood glucose levels by
stimulating glycogenolysis and gluconeogenesis, and mobilizing fatty acids.
6. Growth Hormone (GH)
: Secreted by the pituitary gland, GH promotes growth
and cell reproduction, increases protein synthesis, and mobilizes fatty acids for energy, thus influencing overall metabolic processes.
7. Leptin
: Produced by adipose tissue, leptin regulates energy balance by
inhibiting hunger, thereby controlling food intake and body weight.
8. Ghrelin
: Secreted by the stomach, ghrelin stimulates appetite, increases food
intake, and promotes fat storage, thus playing a significant role in energy balance.

5. References
1. Polonsky, K. S. (2000). "The Beta Cell in Diabetes: Clinical Implications."
Diabetes Care, 23(3), 579-582.
2. Unger, R. H., & Cherrington, A. D. (1981). "Glucagon physiology and
pathophysiology." New England Journal of Medicine, 304(26), 1518-1524.
3. Yen, P. M. (2001). "Physiological and molecular basis of thyroid hormone
action." Physiological Reviews, 81(3),

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7. oRuqqiaBibi (F23-0942)
Topic :
Mechanisms of Hormonal Action
Hormones exert their effects on target cells through various mechanisms, which can be
broadly categorized into two main types based on the nature of the hormone:
peptide/protein hormones and steroid hormones.Here’san overview of these mechanisms
along with key references:
1. Peptide/Protein Hormones Peptide and protein hormones
, which are generally water-
soluble, cannot pass through the lipid bilayer of cell membranes. They exert their effects
through surface receptors on the target cells. The mechanism typically involves the following
steps:
1. Binding to Receptor: The hormone binds to a specific receptor on the cell surface.
2. Activation of Second Messengers: The receptor -hormone complex activates a G-protein,
which in turn activates or inhibits adenylate cyclase, an enzyme that catalyzes the
conversion of ATP to cyclic AMP (cAMP), a second messenger.
3. Signal Transduction Pathways: cAMP activates protein kinase A (PKA) and other
downstream signaling molecules, leading to various cellular responses.
4. Gene Expression: Some peptide hormones can also influence gene expression indirectly by
activating transcription factors. Example: Insulin and its action on glucose uptake.

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References:-Alberts, B., Johnson, A., Lewis, J., et al. (2002). Molecular Biology of the Cell. 4th edition.
New York: Garland Science.-Lodish, H., Berk, A., Kaiser, C. A., et al. (2008). Molecular Cell Biology. 6th
edition. New York: W. H. Freeman.
2. Steroid Hormones Steroid hormones
, being lipid-soluble, can diffuse through the cell membrane and
interact with intracellular receptors. The mechanism involves:
1. Diffusion through Membrane: The steroid hormone diffuses through the plasma membrane into the cell.
2. Binding to Intracellular Receptors: The hormone binds to specific intracellular receptors (usually in the
cytoplasm or nucleus).
3. Hormone- Receptor Complex: The hormone-receptor complex then translocatesto the nucleus, where it
binds to specific DNA sequences, functioning as a transcription factor.
4. Regulation of Gene Expression: This binding alters the transcription of specific genes, leading to
changes in protein synthesis and thus cellular activity.
Example: Cortisol and its role in regulating metabolism.
References
:-O'Malley, B. W., & Means, A. R. (1974). Mechanism of action of the steroid hormones. The New
England Journal of Medicine, 290(23), 1333-1341.- Tsai, M. J., & O'Malley, B. W. (1994). Molecular
mechanisms of action of steroid/thyroid receptor superfamily members. Annual Review of Biochemistry,
63(1), 451-486.

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3. Tyrosine Kinase Receptors Some hormones, such as insulin, act through
receptors that have intrinsic tyrosine kinase activity. This mechanism involves:
1. Binding to Receptor: The hormone binds to the extracellular domain of the
receptor.
2. Receptor Dimerization and Autophosphorylation: The receptor undergoes
dimerization and autophosphorylation on tyrosine residues.
3. Activation of Signaling Cascades: This activates various downstream signaling
pathways, such as the PI3K/AKT pathway, leading to diverse biological effects.
Example: Insulin and its role in glucose metabolism.
References
:-Hunter, T. (2000). Signaling—2000 and beyond. Cell, 100(1), 113-
127.-Schlessinger, J. (2000). Cell signaling by receptor tyrosine kinases. Cell,
103(2), 211- 225.

10. Summary: Hormones exert their effects through complex
and varied mechanisms depending on their nature and the
type of receptor they bind to. These mechanisms are crucial
for maintaining homeostasis and regulating numerous
physiologicalprocesses.

11. oLaibaHameed (F23-0941)
Topic :
Integrated Metabolic Control
Metabolic processes in the body are tightly regulated to maintain homeostasis.
Hormones play a crucial role in coordinating these processes to ensure energy
balance and proper function.
Hormonal Regulation: Hormones such as insulin, glucagon, cortisol, and
adrenaline are key players in metabolic regulation.
Insulin, released by the pancreas, promotes glucose uptake by cells and storage as
glycogen in the liver and muscles.
Glucagon, also from the pancreas, stimulates glycogen breakdown into glucose,
raising blood sugar levels when needed.
Integration of Signals: Hormonal signals are integrated with other metabolic cues,
such as nutrient availability and energy expenditure.
For example
, during fasting, low insulin levels signal the body to switch to using
stored fats for energy.

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Coordination and Feedback
Coordination of Metabolic Pathways: Hormones act on multiple tissues to coordinate
metabolic responses.
For instance, adrenaline stimulates lipolysis in adipose tissue while also promoting
glycogen breakdown in the liver.
Feedback Mechanisms: Metabolic control is finely tuned by feedback mechanisms. -
Negative feedback loops help maintain stability, such as insulin feedback inhibiting
further insulin secretion when blood glucose levels are normal.
Dysregulation and Disease: Dysregulation of hormonal control can lead to metabolic
disorders like diabetes mellitus. Understanding integrated metabolic control is crucial
for developing therapies to manage these conditions effectively.
Conclusion: Integrated metabolic control involves a complex interplay of hormones,
nutrient sensing, and feedback mechanisms to maintain energy balance and overall
health. -Further research into these processes is essential for advancing our
understanding and treatment of metabolicdisorders.

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14. oMuhammad Ahmad (F23-0943)
Topic :
Clinical Relevance andApplications
Insulin
is essential in diabetes management, particularly for type 1 diabetes
and advanced type 2 diabetes, to regulate blood sugar levels. It is also used in gestational diabetes and critical care. Insulin pump therapy offers continuous delivery and improved quality of life. Emerging technologies like artificial pancreas systems are set to revolutionize diabetes management by automating insulin delivery, enhancing patientoutcomes.
Glucagon
is vital for treating severe hypoglycemiain diabetics, enhancing
gastrointestinal imaging, testing pancreatic function, treating esophageal
food impaction, and managing overdoses of beta-blockers and calcium
channel blockers. Its diverse applications underscore its clinicalimportance.

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Thyroid hormonesare essential for treating hypothyroidism (with hormone
replacement) and hyperthyroidism (with medications, radioactive iodine, or
surgery). They are crucial in diagnosing thyroid disorders through function
tests, managing thyroid cancer, and in screening newborns and pregnant
women to prevent developmental issues. Their role in metabolism is also
being researched for obesity and weightmanagement.
Cortisol
is essential for diagnosing and treating adrenal insufficiency (e.g.,
Addison's disease) and Cushing's syndrome. It is used in anti-inflammatory and immunosuppressive treatments for conditions like asthma and rheumatoid arthritis and is studied for its role in stress-related psychiatric disorders and chronichealthissues.
Catecholamines
like epinephrineand norepinephrineare vital in emergency
medicine for conditions like cardiac arrest and anaphylaxis, as well as in stabilizing blood pressure during shock. They also aid in respiratory distress relief, diagnosing conditions such as pheochromocytoma, and understanding psychiatric disorders. Overall, they have broad clinical relevance across
multiple medicalspecialties.

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Growth hormone (GH) is vital for growth, metabolism, and bone density, with
clinical applications in addressing growth disorders, metabolic conditions, and
hormonal imbalances. Despite controversies, its therapeutic potential in
chronic diseases and muscle wasting is under investigation, emphasizing its
importance in clinical practiceandresearch.
Leptinregulates appetite and metabolism, aiding in managing obesity-related
disorders and serving as a diagnostic marker. While its therapy shows promise in rare genetic conditions, its effectiveness in common obesity is limited. Ongoing research offers hope for innovative interventions in metabolic disorders, highlighting its clinicalimportance.
Ghrelin
, the “Hunger hormone," is clinically significant across various medical
fields, influencing appetite regulation, metabolic function, and growth hormone secretion. Its relevance spans eating disorders, obesity management, growth issues, gastrointestinal problems, and mental health. Ghrelin shows promise for therapeutic interventions in conditions such as anorexia, obesity, and gastrointestinaldisorders.