Pit. and GH

Question 1

6 ant. pit hormones and their targets

Answer 1

1. FSH - ovaries/testes
2. LH - ovaries/testes
3. ACTH - adrenals
4. TSH - thyroid
5. Prolactin - mammaries
6. GH - liver

Question 2

what stims and inhibs GH

Answer 2

stim - GHRH

inhib - somatostatin

Question 3

2 patterns in which ant. pit hormones are released

Answer 3

1. pulsatile

2. circadian

Question 4

4 factors that increase GH secretion

Answer 4

1. deficiency in energy substrate (hypoglycemia, exercise, fasting, glocagon injection)
2. increases in circ. AAs
3. Sleep onset
4. hormones and drugs

Question 5

2 types of drugs to increase GH

Answer 5

1. L-dopa and a-andrenergic agonists

2. est and adrogens before epiphysial closure

Question 6

6 factors that decrease GH secretion

Answer 6

1. REM sleep
2. glucose
3. cortisol
4. free fatty acids
5. medroxyprogesterone
6. GH and EGF-I (negative feedback)

Question 7

what type of protein is GH

Answer 7

protein

Question 8

how much GH is bound in plasma and sig.

Answer 8

50% - protects from rapid degradation

Question 9

what is the pathway responsible for GH signaling

Answer 9

JAK-Stat

Question 10

what does GH stimulate

Answer 10

release of IGF-1 in liver

Question 11

what other receptors can IGF-1 bind to?

Answer 11

mostly it’s own, but also insulin and IGF-2

Question 12

what are 4 main effects of GH release

Answer 12

1. bone growth
2. protein syntesis
3. hyperglycemia
4. lipolysis

Question 13

how does GH affect bone growth

Answer 13

increase in the numer of chondrocytes at the epiphyseal plate

Question 14

when are 2 main growth periods in children

Answer 14

1. 1-2

2. puberty

Question 15

what is acromegaly

Answer 15

too much GH in adulthood

Question 16

what are possible effects of acromegaly

Answer 16

1. diabetes: insulin insensitivity
2. lower glucose uptake
3. bitememporal hemianopia
4. bone changes