Format

Send to

Choose Destination
See comment in PubMed Commons below

Cardiovascular actions of python bradykinin and substance P in the anesthetized python, Python regius.

Author information

  • 1School of Biological Sciences, University of Birmingham, Edgbaston, United Kingdom.

Abstract

The cardiovascular actions of python bradykinin (BK) and substance P (SP) have been investigated in the anesthetized ball python, Python regius. Bolus intra-arterial injections of python BK (0.03-3 nmol/kg) produced concentration-dependent increases in arterial blood pressure, heart rate (HR), and cardiac output concomitant with small decreases in systemic resistance and stroke volume. Intra-arterial injection of 3 nmol/kg python BK produced a tenfold increase in circulating concentration of norepinephrine, but epinephrine levels did not change. BK-induced tachycardia was attenuated (>90%) by the beta-adrenergic receptor antagonist sotalol, and the hypertensive response was attenuated (>70%) by the alpha-adrenergic receptor antagonist prazosin, indicating that effects of python BK are mediated at least in part by activation of the extensive network of adrenergic neurons present in vascular tissues. Bolus intra-arterial injections of python SP in the range 0. 01-30 pmol/kg produced concentration-dependent decreases in arterial blood pressure and systemic peripheral resistance concomitant with increases in cardiac output and stroke volume but with only minor effects on HR. The data suggest that kinins play a physiologically important role in cardiovascular regulation in the python.

PMID:
10938242
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk