Possible involvement of K(ATP) channel activation in depressor responses to vasoactive neuropeptides in rats.
I.v. bolus injections of vasoactive intestinal polypeptide (VIP) (0.3 or 1 microg/kg), calcitonin gene-related peptide (CGRP) (0.3 microg/kg) or substance P (0.1 microg/kg) to anesthetized rats reduced blood pressure, accompanied by slight increases in heart rate. Cromakalim (0.3 microg/kg/min) infused i.v. significantly potentiated the depressor responses to VIP and CGRP, but not those to substance P and acetylcholine (ACh) (0.1 microg/kg). Glibenclamide (20 mg/kg, i.v.) significantly inhibited not only the depressor responses to VIP and CGRP, but also the augmentation of the effects of the two agents by cromakalim. These results suggest that the depressor responses to VIP and CGRP are mediated in part through K(ATP) channel activation.
Saito
K
K
Central Research Laboratories, Chugai Pharmaceutical Co., Ltd., Tokyo, Japan.
Sakai
K
K
D018528:ATP-Binding Cassette Transporters; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D019806:Cromakalim / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D054086:KATP Channels; D008297:Male; D015221:Potassium Channels / Q000819:agonists*; D024661:Potassium Channels, Inwardly Rectifying; D051381:Rats; D017207:Rats, Sprague-Dawley; D013373:Substance P / Q000494:pharmacology*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D018528:ATP-Binding Cassette Transporters; D054086:KATP Channels; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; C092520:uK-ATP-1 potassium channel; D019806:Cromakalim; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D015740:Calcitonin Gene-Related Peptide; D000109:Acetylcholine; D005905:Glyburide