Effects of neuromedin-N on the pituitary-adrenocortical axis of dexamethasone-suppressed rats.
Neuromedin-N (NMN) (6 micrograms/100 g body weight for 2 d) partially reversed the dexamethasone (Dx)-induced inhibition of ACTH release and the consequent adrenal atrophy and decrease in glucocorticoid (corticosterone) plasma concentration in rats. Dx administration did not alter the level of circulating mineralocorticoid (aldosterone), but NMN (2 or 6 micrograms/100 g body weight for 2 d) significantly increased it. These findings suggest that the mechanism underlying the glucocorticoid (but not the mineralocorticoid) secretagogue action of NMN involves the stimulation of hypophyseal ACTH release. The hypothesis is advanced that the potent mineralocorticoid secretagogue effect of NMN may be mediated either by a direct action on zona glomerulosa cells or by the enhanced release of other regulatory peptides exerting aldosterone stimulating effect.
Department of Histology and Embryology (School of Medicine), University of Poznan, Poland.
L K
LK
Malendowicz
G G
GG
Nussdorfer
A
A
Markowska
K W
KW
Nowak
L
L
Torlinski
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000450:Aldosterone / Q000097:blood; D000818:Animals; D003907:Dexamethasone / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D005260:Female; D005934:Glucagon / Q000097:blood; D009496:Neurotensin / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000494:pharmacology*; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D011188:Potassium / Q000097:blood; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000097:blood
D010446:Peptide Fragments; C042090:neuromedin N; D009496:Neurotensin; D000450:Aldosterone; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D005934:Glucagon; D012964:Sodium; D011188:Potassium