Autonomic control of cardiovascular adjustments associated with orthostasis in the scansorial snakeBoa constrictor
| Autor: | Luiz Henrique Florindo, Victor Hugo da Silva Braga, Vinicius Araújo Armelin, Augusto Shinya Abe, Ariela Maltarolo Crestani, Igor Noll Guagnoni |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Tachycardia medicine.medical_specialty Physiology 030310 physiology Aquatic Science 010603 evolutionary biology 01 natural sciences 03 medical and health sciences Orthostatic vital signs Internal medicine Heart rate medicine Prazosin Molecular Biology Ecology Evolution Behavior and Systematics 0303 health sciences biology business.industry biology.organism_classification Blood pressure Insect Science Cardiology Animal Science and Zoology Boa constrictor Orthostatic tachycardia medicine.symptom business Vasoconstriction medicine.drug |
| Zdroj: | Journal of Experimental Biology. |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.197848 |
| Popis: | Orthostatic hypotension is a phenomenon triggered by a change in the position or posture of an animal, from a horizontal to a vertical head-up orientation, characterised by a blood pooling in the lower body and a reduction in central and cranial arterial blood pressure ( P A ). This hypotension elicits systemic vasoconstriction and tachycardia, which generally reduce blood pooling and increase P A . Little is known about the mediation and importance of such cardiovascular adjustments that counteract the haemodynamic effects of orthostasis in ectothermic vertebrates, and some discrepancies exist in the information available on this subject. Thus, we sought to expand our knowledge on this issue by investigating it in a more elaborate way, through an in vivo pharmacological approach considering temporal circulatory changes during head-up body inclinations in unanaesthetised Boa constrictor . To do so, we analysed temporal changes in P A , heart rate ( f H ) and cardiac autonomic tone associated with 30 and 60 deg inclinations, before and after muscarinic blockade with atropine, double blockade with atropine and propranolol, and α 1 -adrenergic receptor blockade with prazosin. Additionally, the animals9 f H variability was analysed. The results revealed that, in B. constrictor : (1) the orthostatic tachycardia is initially mediated by a decrease in cholinergic tone followed by an increase in adrenergic tone, a pattern that may be evolutionarily conserved in vertebrates; (2) the orthostatic tachycardia is important for avoiding an intense decrease in P A at the beginning of body inclinations; and (3) α 1 -adrenergic orthostatic vasomotor responses are important for the maintenance of P A at satisfactory values during long-term inclinations. |
| Databáze: | OpenAIRE |
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