Effects of neurotensin and bombesin on the secretory and proliferative activity of regenerating rat adrenal cortex.
Neurotensin (NT) and bombesin (BM)-like peptides are known to be involved in the regulation of the rat hypothalamo-pituitary-adrenal axis. By using selective NT- and BM-receptor antagonists (NT-A and BM-A, respectively) we investigated whether endogenous NT and BM-like peptides play a role in the control of rat adrenal secretion and growth during enucleation-induced regeneration. At day 5 of regeneration, NT-A did not affect the plasma concentrations of aldosteronc (PAC) and corticosterone (PBC), but at day 8, it raised both PAC and PBC over the respective baseline value; the simultaneous administration of NT abolished this effect of NT-A. BM-A did not alter PAC and PBC at day 5 of regeneration, while at day 8 it enhanced PBC, an effect reversed by BM. NT-A did not alter mitotic index, and BM-A lowered it at both day 5 and day 8 of regeneration, an effect suppressed by the simultaneous administration of BM. Collectively, these findings allow us to draw the following conclusions: 1) endogenous NT and BM-like peptides influence adrenocortical regeneration in rats; 2) NT exerts a tonic inhibitory action on both aldosterone and corticosterone secretion, without affecting cell-proliferation rate; and 3) BM-like peptides exert a tonic suppressive effect on corticosterone production, coupled with a clear-cut stimulating effect on cell proliferation.
Hochol
A
A
Department of Histology and Embryology, School of Medicine, Poznan, Poland.
Markowska
A
A
Meneghelli
V
V
Jedrzejczak
N
N
Majchrzak
M
M
Nowak
M
M
Nussdorfer
G G
GG
Malendowicz
L K
LK
D000302:Adrenal Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D000450:Aldosterone / Q000097:blood; D000818:Animals; D001839:Bombesin / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D002455:Cell Division / Q000187:drug effects; D003345:Corticosterone / Q000097:blood; D005260:Female; D009496:Neurotensin / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology*
C051813:bombesin, Tyr(4), Phe(12)-; D009496:Neurotensin; D000450:Aldosterone; C024309:neurotensin, Trp(11)-; D001839:Bombesin; D003345:Corticosterone