Effects of ritanserin, a specific serotonin-S2 receptor antagonist, on the release of anterior pituitary hormones during insulin-induced hypoglycemia in normal humans.
The role of serotonin in the insulin hypoglycemia (IH) stimulated secretion of prolactin (PRL), growth hormone (GH), adrenocorticotropin (ACTH) and cortisol (F) was studied in a group of 12 normal subjects during the control period after placebo and a consecutive six-day treatment with 20 mg ritanserin (RIT) per day. RIT failed to affect the baseline levels of all the four hormones as well as the PRL response to IH (p > 0.5). The serum GH response to IH was moderately diminished after RIT, the reduction of integrated trapezoidal area under hormone curves (nAUC) being 50.7% +/- 6.9% (p < 0.005). Furthermore, RIT was found to slightly decrease the plasma ACTH response to IH, the reduction of nAUC being 36.3% +/- 2.6% (p < 0.005). Decrease in the corresponding plasma F response to IH was accompanied by 29.1% +/- 2.4% reduction of nAUC (p < 0.005). According to our results, serotonin-S2 receptors appeared to be moderately involved in IH-induced release of GH, but slightly in that of ACTH, leaving unaffected that of PRL.
Tepavcević
D
D
Department of Internal Medicine, Zagreb University School of Medicine, Croatia.
Giljević
Z
Z
Aganović
I
I
Korsić
M
M
Halimi
S
S
Suchanek
E
E
Jelić
T
T
Kozić
B
B
Plavsić
V
V
D000328:Adult; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D010908:Pituitary Hormones, Anterior / Q000378:metabolism*; D016713:Ritanserin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology*
D007004:Hypoglycemic Agents; D007328:Insulin; D010908:Pituitary Hormones, Anterior; D012702:Serotonin Antagonists; D016713:Ritanserin