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The role of nitric oxide in the regulation of the systemic and pulmonary vasculature of the rattlesnake,Crotalus durissus terrificus.
- Source :
- Journal of Comparative Physiology B: Biochemical, Systemic & Environmental Physiology; Apr2005, Vol. 175 Issue 3, p201-208, 8p
- Publication Year :
- 2005
-
Abstract
- The functional role of nitric oxide (NO) was investigated in the systemic and pulmonary circulations of the South American rattlesnake,Crotalus durissus terrificus. Bolus, intra-arterial injections of the NO donor, sodium nitroprusside (SNP) caused a significant systemic vasodilatation resulting in a reduction in systemic resistance (Rsys). This response was accompanied by a significant decrease in systemic pressure and a rise in systemic blood flow. Pulmonary resistance (Rpul) remained constant while pulmonary pressure (Ppul) and pulmonary blood flow (Qpul) decreased. Injection ofL-Arginine (L-Arg) produced a similar response to SNP in the systemic circulation, inducing an immediate systemic vasodilatation, while Rpul was unaffected. Blockade of NO synthesis via the nitric oxide synthase inhibitor, L-NAME, did not affect haemodynamic variables in the systemic circulation, indicating a small contribution of NO to the basal regulation of systemic vascular resistance. Similarly, Rpul and Qpul remained unchanged, although there was a significant rise in Ppul. Via injection of SNP, this study clearly demonstrates that NO causes a systemic vasodilatation in the rattlesnake, indicating that NO may contribute in the regulation of systemic vascular resistance. In contrast, the pulmonary vasculature seems far less responsive to NO. [ABSTRACT FROM AUTHOR]
- Subjects :
- RATTLESNAKES
NITRIC oxide
BLOOD vessels
CROTALUS
BLOOD circulation
AMINO acids
Subjects
Details
- Language :
- English
- ISSN :
- 01741578
- Volume :
- 175
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Journal of Comparative Physiology B: Biochemical, Systemic & Environmental Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 16635402
- Full Text :
- https://doi.org/10.1007/s00360-005-0476-2