Effects of neuromedin U-8 on the rat pituitary-adrenocortical axis.
A single subcutaneous injection of 6 micrograms/100 g body wt. of neuromedin U-8 (NMU8) resulted in a transient increase in ACTH blood concentration (between 3 and 12 h) and a sustained (24 h) elevation of plasma corticosterone (B) concentration (PBC). After a 2-day subcutaneous administration of NMU8 (2 or 6 micrograms/100 g/day) blood ACTH level remained unchanged, but PBC was notably raised. Adrenal glands were atrophic, due to a marked loss of parenchymal cells, but in spite of this their basal in vitro output of B did not differ from that of control glands. These findings indicate that NMU8 stimulates pituitary-adrenocortical axis in rats. Furthermore, they suggest that, in addition to the enhancement in ACTH release, other mechanism(s) must be involved in the adrenocortical secretagogue effect of NMU8.
Malendowicz
L K
LK
Department of Histology and Embryology (School of Medicine), University of Poznan, Poland.
Nussdorfer
G G
GG
Nowak
K W
KW
Mazzocchi
G
G
D000311:Adrenal Glands / Q000187:drug effects / Q000473:pathology; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D001284:Atrophy; D002452:Cell Count / Q000187:drug effects; D003345:Corticosterone / Q000378:metabolism*; D005260:Female; D007279:Injections, Subcutaneous; D009479:Neuropeptides / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D010902:Pituitary Gland / Q000187:drug effects / Q000473:pathology; D010913:Pituitary-Adrenal System / Q000187:drug effects* / Q000378:metabolism; D051381:Rats
D009479:Neuropeptides; D000324:Adrenocorticotropic Hormone; C046270:neuromedin U 8; D003345:Corticosterone