Hypothalamic and Pituitary Pharm Flashcards
Describe the control of anterior pituitary hormone release
- Release of hypothalamic hormones (releasing factors) under CNS control via neurotransmitters (NE, DA, GABA, 5HT, ACh)
- Release of anterior pituitary hormones (trophic hormones) is controlled by hypothalamic hormones (either releasing or inhibiting factors) that are synthesized in and released from peptidergic neurons. They are then delivered via portal circulation to the pituitary gland for release into the systemic circulation where they act on endocrine glands to regulate production of hormones that perform ultimate regulatory functions
Describe the control of anterior pituitary hormone release
- released of hypothalamic HR under CNS control via neurotransmitters (DA, NE, GABA, 5HT, ACh)
- Release of ant. pit. HR is controlled by HYPOTHALAMIC HRs
Describe what anterior and posterior pit. hormones act on
Ant: ON ENDOCRINE glands to regulate production of hormones that perform ultimate regulatory fxn
Post: act DIRECTLY ON TARGET TISSUES to perform regulatory fxns
Another name for GH
Somatropin
What is the PK of GH including form, peak level time, and duration of action
Form: SC or IM
Peak levels: 2-4 hrs
Active level persist 36 hrs
GH release is increased by:
- GHRH**
- Hypoglycemia
- DA, I-DOPA
- Exercise
- Arginine (and Ghrelin)
GH produces __ and __ effects including:
Anabolic and metabolic effects
- Positive nitrogen balance
- Stimulate lipolysis
- Increase FFA and blood glucose*
At pharmacologic doses GH works indirectly to stimulate synthesis of ___ promoting ___ and __
Insulin-like growth factors (IGF-1, IGF-2 in growth plate cartilage and liver)
linear and skeletal muscle growth
Uses of GH (aka Somatropin)
- Replacement therapy in children w/ deficiency
- Poor growth due to Turner Syndrome, Prader-Willi Syndrome, CRI
- GH def. in adults
- Wasting and cachexia in AIDS pt
- Short bowel syndrome dependent on TPN
- idiopathic short stature is controversial
How is GH administered for GH deficiency in children
- SC daily injections at bedtime
2. 3x a week IM
recombinant IGF-1 (Mecasermin) creates concern for
hypoglycemia, so carb intake prior to injection
What are illicit uses of GH
- athletes to increase muscle mass and improve performance (lack control studies)
- healthy elderly for anti-aging
GH side effects when misued in atheletes
- acromegaly
- arthropathy
- visceromegaly
- extremity enlargement
A 3-year-old boy with failure to thrive and metabolic disturbances was found to have an inactivating mutation in the gene that encodes the growth hormone receptor. Which of the following drugs is most likely to improve his metabolic function and promote growth? A. Dopamine B. Bromocriptine C. Mecasermin D. Octreotide E. Somatropin
C. Mecasermin
A 3-year-old girl was referred to the genetic counselor by her pediatrician. She presents with short stature (3 standard deviations below norm) and appears to have loose skin on her neck. Cytogenetic testing reveals an XO karyotype (e.g., Turners syndrome). Which of the following drugs will allow her to achieve a higher adult height?
A. Growth hormone releasing hormone (GHRH)
B. Somatropin
C. Insulin-like growth factor
D. Somatostatin
E. Bromocriptine
B. Somatropin
What are SE of GH used in healthy elderly for anti-aging
- Edema
- Joint pain
- muscle pain
- carpal tunnel syndrome
- skin numbness and tingling
- increase growth of premalignant cells
Describe effects of Somatotstatin
- Inhibits release of GR via GPCR coupled to Gi/o
- Decrease secrtion of gastric enzymes and acid
- decrease GI motility
- decrease release of serotonin and gastroenteropancreatic peptides
- Reduce insulin and glucagon release
- interferes w/ TRH ability to release TSH