Hypophysiotropic hormones meaning?
List out the hormones and their function?
_The hypophysiotropic hormones are secreted by the anterior pituitary; they act as signals to the gland, causing it to secrete its hormones
*TRH: release TSH and prolactin
*GnRH: release LH and
FSH
*CRH: release ACTH
*GHRH: release GH
*Somatostatin:
inhibit GH and TSH
*Dopamine: inhibit prolactin
What are regulatory hormones? (from what gland?)
The three hypothalamic regulatory hormones are
_thyrotrophin-releasing hormone (TRH)
_luteinizing hormone/follicle-stimulating hormone-releasing hormone (LH/FSH-RH)
_growth hormone-release inhibiting hormone (GH-RIH)
Anterior pituitary hormones? (name, target gland, feedback hormone**?
Adrenocorticotrophic hormone (ACTH) -> adrenal cortex
**cortisol
Thyroid-stimulating hormone (TSH) -> thyroid
gland
**T4/T3 negative feedback
Luteinizing hormone (LH) -> testicle (make testosterone);
ovaries (estrogen, progesterone)
**Androgens
exert negative feedback GnRH, FSH, and LH
Follicle-stimulating hormone (FSH) ->testis,
ovary
**inhibin, estradiol -> negative
feedback: inhibit FSH and LH
Prolactin (PRL) -> breast
**Dopamine
Growth hormone (GH) -> multiple
targets
**IGF-1 (Insulin-like Growth Factor-1)
Which ones are dimeric glycoprotein? Which ones are single peptide?
_glycoprotein: LH, FSH, TSH
_ACTH, GH, PRL: single peptide
GH stimulators?
_Sleep, exercise, stress; hypoglycemia
_Amino acid, sex steroids, alpha-agonist (NE), beta blocker (propranolol)
GH inhibitors?
_Glucose loading, stress, insulin deficiency, thyroxine deficiency
_alpha-blocker (phentolamine), beta-agonist (EPI)
Normal ranges of GH?
_GH: 0.01-1 (males), 0.01-3.5 (females)
First test for testing method for GH?
Describe the 75g glucose tolerance test for GH? (timeframes to measure, results for normal individuals, how about patients with acromegaly?
IGF-1 is the first test for assessing deficiency or excess growth during childhood
_30, 60, 90, 120 mins after glucose ingestion; undetectable in normal; GH fail to suppress (or elevated) in acromegaly patients
Gold standard for GH deficiency test?
other tests (more comfortable for patients)?
_insulin induced hypoglycemia
_infusion GHRH, L-arginine, oral levodopa
Results of GH excess or pituitary tumor? (think GH as insulin antagonist)
What happen when GH producing tumor before and after puberty?
GH excess has cosecretion with what other hormone?
_Symptoms: glucose intolerance, diabetes, HTN, muscle+bone weakness; hypermetabolic (sweating, heat intolerance)
_Before: gigantism
_After: acromegaly (bony, soft-tissue overgrowth)
_Cosecretion with PRL
Definitive test for GH excess?
_GH not suppressed with glucose loading
3 classes of agents for GH suppression?
_SS analog, dopaminergic agonist (both receptor binding and produce response), GH receptor antagonist (only binding receptor)
Symptoms of GH deficiency syndrome?
_withdrawal, fatigue, loss of motivation, osteoporosis
Treatment for GH deficient?
_GH replacement therapy, with recombinant human GH (expensive)
Difference between a tropic and a direct effector hormone?
Which type PRL belongs to?
_Direct hormones affect different target tissues and no single endocrine end organ (tropic hormones need to involve other endocrine glands)
_PRL is a direct effector hormone
Causes of hypopituitarism?
_Tumor (pituitary, parapituitary, hypothalamic)
_Trauma, infection, infarction, infiltrative disease
_Radiation therapy/surgery, immunologic
_Familial, idiopathic
Treatment of panhypopituitarism:
_Thyroxine, glucocorticoids, sex steroids
PRL inhibitor?
stimulator?
_Dopamine
_stimulator is TRH, estrogens
Cause of PRL excess?
Consequence of PRL excess?
_Tumor or trauma in pituitary stalk
_hypogonadism (suppression of GnRH or inhibit gonadotropin at the gonad) -> can cause osteoporosis
Most common type of functional pituitary tumor?
Symptoms?
_prolactinoma
_Female (amenorrhea, infertility, galactorrhea), men (headache, vision problems, ED)