Age-related decrease of neurogenic release of calcitonin gene-related peptide from perivascular nerves in spontaneously hypertensive rats.
Changes in the neurogenic release of calcitonin gene-related peptide (CGRP) by perivascular nerve stimulation (PNS) were investigated in perfused mesenteric vascular beds isolated from spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY). CGRP-like immunoreactivity (CGRP-LI) in the perfusate was examined by radioimmunoassay (RIA) and identified to be CGRP itself by combined analysis with radioimmunoassay and HPLC. In SHR and WKY preparations, PNS (4 and 8 Hz) evoked a frequency-dependent increase of CGRP-LI in the perfusate, which was abolished by 500 nM tetrodotoxin and the removal of Ca2+ from the medium. In young SHR and WKY (8-week-old), there was no significant difference in the release of CGRP-LI induced by PNS, whereas the release in the 15-week-old SHR was significantly less than in the 15-week-old WKY and in 8-week-old SHR. These results suggest that neural release of CGRP from perivascular nerves in mesenteric resistance vessels of SHR decreases with age.
Kawasaki
H
H
Department of Pharmacology, Miyazaki Medical College, Japan.
Takasaki
K
K
D000375:Aging / Q000502:physiology*; D000818:Animals; D001808:Blood Vessels / Q000294:innervation*; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004558:Electric Stimulation; D006973:Hypertension / Q000378:metabolism*; D008297:Male; D009424:Nervous System Physiological Phenomena; D011863:Radioimmunoassay; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D015740:Calcitonin Gene-Related Peptide