Effect of galanin on basal and stimulated secretion of prolactin, gonadotropins, thyrotropin, adrenocorticotropin and cortisol in humans.
Galanin enhances both baseline and growth hormone-releasing hormone (GHRH)-induced GH secretion both in animals and in man. Although galanin has a clear influence on the secretion of other anterior pituitary hormones in animals, in man it increases prolactin (PRL) slightly but does not affect spontaneous thyrotropin (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH) or adrenocorticotropin (ACTH) secretion. The aim of our study was to verify the effect of galanin on basal and releasing hormone-stimulated release of gonadotropins, PRL, TSH, ACTH and cortisol secretion. As GH release has been shown to be inhibited by corticotropin-releasing hormone (CRH), we also studied the effect of CRH on galanin-stimulated GH increase. The effect of porcine galanin (15 micrograms/kg iv infused in 60 min) alone and in combination with thyrotropin-releasing hormone (TRH, 200 micrograms iv bolus), CRH (100 micrograms iv bolus) and gonadotropin-releasing hormone (GnRH, 100 micrograms iv bolus) on GH, PRL, TSH, ACTH, cortisol, FSH and LH secretion in seven normal young women (aged 25-30 years) was studied. Galanin infusion caused an increase in serum GH levels (p < 0.02) but failed to modify significantly the spontaneous PRL, LH, FSH, TSH, ACTH and cortisol secretion. The combined administration of TRH, GnRH and CRH caused a significant increase in PRL (p < 0.02), LH (p < 0.02), FSH (p < 0.02), TSH (p < 0.02), ACTH (p < 0.02) and cortisol (p < 0.05), but not in GH levels.(ABSTRACT TRUNCATED AT 250 WORDS)
Arvat
E
E
Department of Pathophysiology, Ospedale Molinette, Turin, Italy.
Gianotti
L
L
Ramunni
J
J
Grottoli
S
S
Brossa
P C
PC
Bertagna
A
A
Camanni
F
F
Ghigo
E
E
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000328:Adult; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D019004:Galanin / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D006065:Gonadotropins, Pituitary / Q000378:metabolism*; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism*; D013972:Thyrotropin / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
D006065:Gonadotropins, Pituitary; D007987:Gonadotropin-Releasing Hormone; D013973:Thyrotropin-Releasing Hormone; D019004:Galanin; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013006:Growth Hormone; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone