Cardiovascular effects of histamine in three widely diverse species of reptiles

Autor(es)

Skovgaard, Nini ^{[1, 2]} ; Abe, Augusto S. ^[1] ; Taylor, Edwin W. ^{[1, 3]} ; Wang, Tobias ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] UNESP, Ctr Aquicultura, Dept Zool, Rio Claro - Brazil

^[2] Aarhus Univ, Dept Biosci, Zoophysiol, C-F Mollers Alle 3, Bldg 1131, DK-8000 Aarhus C - Denmark

^[3] Univ Birmingham, Sch Biosci, Birmingham, W Midlands - England

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL; v. 188, n. 1, p. 153-162, JAN 2018.
• Citações Web of Science: 3

Resumo

The cardiovascular system of vertebrates is regulated by a vast number of regulatory factors, including histamine. In pythons, histamine induces a strong tachycardia and dilates the systemic vasculature, which resembles the cardiovascular response to the elevated metabolic rate during digestion. In fact, there is an important role of increased histaminergic tone on the heart during the initial 24 h of digestion in pythons. Whilst the cardiovascular effects of histamine are well studied in pythons, little is known about the effects in other groups of reptiles. The histaminergic effects on the heart vary among species and histamine may exert either pressor and depressor effects by causing either constrictive or dilatory vascular responses. Here, we investigated the cardiovascular effects of histamine in three species of reptiles with very different cardiovascular and pulmonary morphologies. Experiments were performed on both anesthetized and recovered animals. We show a species-dependent effect of histamine on the systemic vasculature with dilation in rattlesnakes and constriction in turtles and caimans but no effect on the pulmonary circulation. The histamine-induced dilation in rattlesnakes was mediated through an activation of H-2-receptors, whereas the histamine-induced constriction in caimans was mediated through both adrenergic signaling and H-1-receptors activation. In all three species, histamine-induced tachycardia by direct stimulation of histaminergic receptors as well as an indirect activation of adrenoreceptors. This finding highlights a more complex mechanism underlying the action of histamine than previously recognized in reptiles. (AU)

• Processo FAPESP: 12/06938-8 - Desenvolvimento do controle neural no sistema cardiovascular de répteis
• Beneficiário: Augusto Shinya Abe
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional