Prolonged kallikrein inhibition does not affect the basal growth and secretory capacity of rat adrenal cortex, but enhances mineralo- and glucocorticoid response to ACTH and handling stress.
The effects on the pituitary-adrenocortical functions of the prolonged (7-day) blockade of endogenous bradykinin (BK) synthesis, obtained by the administration of the kallikrein inhibitor (K-I) cyclohexylacetyl-Phe-Arg-Ser-Val-Gln amide, were investigated in the rat. K-I treatment did not cause significant changes in the (i) body and adrenal weights; (ii) basal plasma levels of ACTH, aldosterone and corticosterone; and (iii) average volume of adrenocortical cells and their basal secretory capacity. Conversely, K-I administration induced a significant magnification of the in vivo mineralo- and glucocorticoid responses to the intraperitoneal (i.p.) bolus injection of ACTH. Moreover, K-I-treated rats, but not control ones, displayed a moderate and short-term adrenal secretory response to the mild stress evoked by the placebo i.p. injection. Collectively, these findings rule out the possibility that endogenous BK plays a relevant role in the control of adrenocortical function under basal conditions. However, they suggest that endogenous BK may be involved in quenching exceedingly high adrenocortical responses to ACTH and stresses.
Rebuffat
P
P
Department of Human Anatomy and Physiology, University of Padua, Italy.
Neri
G
G
Bahçelioglu
M
M
Malendowicz
L K
LK
Nussdorfer
G G
GG
D000302:Adrenal Cortex / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage / Q000378:metabolism*; D000450:Aldosterone / Q000097:blood*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001920:Bradykinin / Q000378:metabolism*; D003345:Corticosterone / Q000097:blood*; D005938:Glucocorticoids / Q000097:blood; D006801:Humans; D007610:Kallikreins / Q000037:antagonists & inhibitors*; D008901:Mineralocorticoids / Q000097:blood; D009842:Oligopeptides / Q000008:administration & dosage / Q000378:metabolism*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D015842:Serine Proteinase Inhibitors / Q000008:administration & dosage / Q000378:metabolism*; D013997:Time Factors
D005938:Glucocorticoids; D008901:Mineralocorticoids; D009842:Oligopeptides; D015842:Serine Proteinase Inhibitors; C062276:KKI 7; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D007610:Kallikreins; D001920:Bradykinin; D003345:Corticosterone