Calcitonin gene-related peptide does not interact with sympathetic activity in myocardial ischemia.
The aim of the present study was to assess whether calcitonin gene-related peptide (CGRP) modulates exocytotic norepinephrine release in ischemic myocardium. In isolated rat hearts subjected to 30 min of low flow ischemia, CGRP release increased 2.8-fold whereas stimulation-induced norepinephrine release decreased 4.1-fold. Pretreatment of rats with capsaicin almost completely depleted cardiac CGRP stores; however, suppression of norepinephrine release by 30 min of low flow ischemia was not affected. At normal flow, exogenous CGRP (5 micromol l-1) had no effect on norepinephrine release. These findings suggest that CGRP release from sensory neurons does not interact with the cardiac sympathetic system during myocardial ischemia.
Burgdorf
Christof
C
Medizinische Klinik II, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany. chbrg@compuserve.de
Dendorfer
Andreas
A
Kurz
Thomas
T
Richardt
Gert
G
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism / Q000502:physiology*; D002211:Capsaicin / Q000494:pharmacology; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D017202:Myocardial Ischemia / Q000188:drug therapy*; D015428:Myocardial Reperfusion Injury / Q000473:pathology; D009206:Myocardium / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D018377:Neurotransmitter Agents; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000378:metabolism; D013997:Time Factors
D018377:Neurotransmitter Agents; D018015:Receptors, Calcitonin Gene-Related Peptide; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin; D009638:Norepinephrine