Baroreflex responses of decerebrate rattlesnakes (Crotalus durissus) are comparable to awake animals

Autor(es)

Tavares, Driele ; Matos, Sofia Lopes Basilio da Silva ; Duran, Livia Maria ; Castro, Samanta A. ; Taylor, Edwin William ; Filogonio, Renato ; Fernandes, Marisa Narciso ; Leite, Cleo A. C.

• Tipo de documento: Artigo Científico
• Fonte: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY; v. 273, p. 8-pg., 2022-08-10.

Resumo

A decerebrate rattlesnake, Crotalus durissus, has previously been used as a model Squamate for cardiovascular studies. It enabled instrumentation for concomitant recordings of diverse variables that showed autonomic re-sponses. However, to validate the preparation and its scope for use, it is necessary to assess how close its car-diovascular variables are to non-decerebrate snakes and the effectiveness of its autonomic responses. Similarly, it is important to analyze its recovery profile after instrumentation and observe if it maintains stability throughout the duration of experimental protocol. Here we have objectively assessed these points by comparing decerebrate preparations and non-decerebrate snakes, after the occlusive cannulation of the vertebral artery. We have assessed cardiovascular variables and the baroreflex to analyze the presence, magnitude and stability of complex autonomic-controlled parameters as indicators of autonomic nervous system (ANS) functionality. After instru-mentation, mean heart rates were high but recovered to stable values within 24 h. Mean arterial pressure sta-bilized within 24 h in control snakes and 48 h in decerebrate preparations. After that, both parameters remained stable. The operational gain and effectiveness index of the baroreflex recovered within the first 6 h after instrumentation in both experimental groups. In addition, the baroreflex capacities and its limits were also equivalent between the groups. These experiments demonstrated that decerebrate preparations and inactive, non-decerebrate snakes showed comparable recovery profiles following anesthesia and cannulation, maintained similar values of cardiovascular variables during experimental manipulation and exhibited functional, ANS modulated reflexes. Accordingly, the present results attest the relevance of this decerebrate preparation for studies on cardiovascular modulation. (AU)

• Processo FAPESP: 16/20158-6 - Adaptações morfofuncionais cardiovasculares para a relação alométrica entre pressão arterial e massa em répteis
• Beneficiário: Renato Filogonio
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/05035-0 - Ajustes cardiovasculares em Squamata: validação do modelo da cascavel descerebrada para estudos de mecanismos regulatórios cardiovasculares
• Beneficiário: Cléo Alcantara Costa Leite
• Modalidade de apoio: Auxílio à Pesquisa - Regular