In vivo and in vitro effects of bradykinin on the release of beta-endorphin-like immunoreactivity.
The effect of bradykinin (BK) on the release of beta-endorphin-like immunoreactivity (beta-EpLI) in rats was studied in vivo and in vitro. Intraperitoneal injection of BK at 5 micrograms/100 g body weight resulted in significant increase in the plasma beta-EpLI level after 15 min. BK at concentrations of 10(-12)-10(-7) M also caused dose-dependent stimulation of beta-EpLI release from dispersed cells of rat anterior pituitary. On gel chromatography, the beta-EpLI released by incubation of the cells with 10(-7) M BK separated into two components, eluted in the same positions as human beta-lipotropin and human beta-endorphin, respectively. BK did not stimulate beta-EpLI release in Ca++-free medium. Addition of 10(-3) M verapamil or 10(-6) M dexamethasone to the incubation medium inhibited BK-induced beta-EpLI release from the cells. Quabain (10(-5) M) also stimulated beta-EpLI release, but its effect was not additive with that of BK. These results indicate that BK stimulates beta-EpLI release and that calcium ion is involved in the mechanism of this effect.
Matsumura
M
M
Ohura
M
M
Shimizu
I
I
Yamonoi
A
A
Iwasaki
A
A
Saito
S
S
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology*; D003907:Dexamethasone / Q000494:pharmacology; D004723:Endorphins / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology; D001615:beta-Endorphin
D004723:Endorphins; D010042:Ouabain; D001615:beta-Endorphin; D003907:Dexamethasone; D014700:Verapamil; D001920:Bradykinin; D002118:Calcium