51-STEROID HORMONE METABOLISM (LECTURE #2 & 3) – Dr. Venk Flashcards
What is the second messenger that stimulates the synthesis and secretion of cortisol?
P-t450 hydroxylase enzymes.
What is the second messenger that stimulates the synthesis and secretion of aldosterone?
Phosphotidylinositol cascade.
Name the second messenger that is produced as a result of atrial natriuretic factor binding to kidney cells.
cGMP is the second messenger.
Guanylate cyclase catalyzes the formation of…
cGMP
Cholesterol esterase catalyzes the formation of…
cholesterol and fatty acids
The hormone that triggers synthesis and secretion of adrenal steroids is…
ACTH
Desmolase (20,22-lyase) catalyzes the formation of
pregnenolone
CYP is defined as _____.
CYP stands for genes that encode for cytochrome P450 hydroxylase enzymes.
The conversion of angiotensin I to angiotensin II is catalyzed by .
angiotensin converting enzyme (ACE)
In congenital adrenal hyperplasia, the enzyme that is deficient is …
CYP21A2 (cytochrome P450 steroid 21-hydroxylase
Adrenal insufficiency causes … disease
Addison’s disease
Name 2 reasons for Cushing’s syndrome.
Prolonged exposure to glucocorticoids caused by usage of anti inflammatory drugs or tumors of adrenal cortex.
Name an adrenal steroid that causes HTN upon its overproduction.
Mineralocorticoids, such as epinephrine, can cause HTN upon excessive secretion.
Name an aldosterone antagonist.
Spironolactone, cGMP, Lisinopril, Enalipril, and Captopril are aldosterone antagonists.
Name 2 competitive inhibitors of ACE.
Captopril, lisinopril and enalapril are competitive inhibitors of ACE.
Pregnancy is maintained by continuous secretion of progesterone, which is stimulated by the hormone …
LH
Describe how apoptosis is stimulated during the ovarian cycle.
Apoptosis is stimulated during ovarian cycle by the removal of the steroids estradiol and progesterone.
Testosterone to estradiol conversion is catalyzed by …
aromatase
Two hormones that stimulate luteolysis are …
oxytocin and PGF2α
Human placenta lacks the hydroxylase enzyme …
CYP17
Testicular feminization is the result of deficiency of …
5α-reductase