Page 76 - Physiology and Pathophysiology MNU 2024-2025 نظرى
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Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)
Biochemical classification of Hormones
1- Steroid hormones 2- Protein/peptide hormones
Synthesis from cholesterol on demand derived from amino acids
lipid soluble water soluble
a. cross cell membranes a. unable to cross the cell membranes
readily & bind to intracellular bind to receptors on the
receptors membrane surface
b. Insoluble in blood b. circulate in the blood in unbound
transported in the blood form have short half-lives.
bound to proteins have
character long half-lives.
c. not preformed & stored for c. Preformed & stored for future use
future use within the in membrane-bound secretory
endocrine gland Because granules When needed, they are
they could diffuse out of the released by exocytosis.
cells and physiological
regulation of their release
would not be possible
d. Absorbed easily by the d. cannot be administered orally
gastrointestinal tract so, because they would be digested in
administered orally. the gastrointestinal tract. Instead,
1- Administered by injection (e.g.,
insulin).
Synthetic 2- Because small peptides are able to
forms cross through mucus membranes,
they may be given sublingually or
intranasally.
For example, Miacalcin (synthetic
form of calcitonin, prepared as
nasal spray).
adrenal cortex, testes, ovaries, Hypothalamus, pituitary gland, thyroid
production
and placenta gland, parathyroid glands & pancreas
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