Capsaicin-sensitive nerves influence the release of atrial natriuretic factor by atrial stretch in the rat.
Although many factors may modulate the release of atrial natriuretic factor (ANF), the primary mechanism has been demonstrated to be atrial stretch. Recent studies have led to the suggestion that the peptidergic innervation of the heart, through the release of peptides, may be involved in the control of ANF secretion. We have examined the influence of chronic capsaicin treatment on three models of atrial stretch that release ANF. This treatment inhibited ANF released through in vivo blood volume expansion and through balloon inflation in the right atrium of in vitro isolated perfused hearts. Immunohistochemical and electron microscopical analysis confirmed the absence of innervation of the heart by calcitonin gene related peptide and substance P immunoreactive nerve fibres and apparent lack of effect on atrial granules in capsaicin treated rats. We conclude that capsaicin-sensitive cardiac innervation is a component modulating the release of ANF, stimulated by atrial stretch in the rat.
Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
A J
AJ
Rankin
T M
TM
Scott
D000818:Animals; D016275:Atrial Function; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D001810:Blood Volume; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D006325:Heart Atria / Q000187:drug effects; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D009412:Nerve Fibers / Q000187:drug effects / Q000378:metabolism; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D013314:Stress, Mechanical; D013373:Substance P / Q000378:metabolism
C472610:atrial natriuretic peptide, rat; D013373:Substance P; D009320:Atrial Natriuretic Factor; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin