Is compensatory vasoconstrictor tone in the hindquarter vascular region induced by hemorrhage in conscious spontaneously hypertensive rats?

Jpn J Pharmacol. 2001 Jan;85(1):109-13. doi: 10.1254/jjp.85.109.

Abstract

We investigated whether a compensatory vasoconstrictor action would be induced by a hypotensive intervention in the hindquarter vascular region of conscious spontaneously hypertensive rats (SHRs). Mean arterial pressure and hindquarter blood flow were recorded. After hemorrhage (withdrawing blood, 0.3 ml/100 g body weight), hindquarter resistance (HQR) was increased significantly. The decrease in HQR induced by the administration of a ganglionic blocker (C6; 25 mg/kg, i.v.) was significantly greater in SHRs with hemorrhage than in those without hemorrhage. The present results suggest that a detectable hindquarter compensator tone occurs due to hemorrhage in SHRs, although an abnormal substantial vasoconstrictor tone already exists in the hindquarters.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Aorta, Abdominal
  • Blood Flow Velocity
  • Blood Pressure / physiology
  • Consciousness
  • Ganglionic Blockers / pharmacology
  • Hemorrhage / physiopathology*
  • Hexamethonium / pharmacology
  • Hindlimb / blood supply*
  • Hypotension / physiopathology
  • Male
  • Rats
  • Rats, Inbred SHR
  • Rats, Wistar
  • Regional Blood Flow / physiology
  • Vascular Resistance / drug effects
  • Vascular Resistance / physiology*
  • Vasoconstriction / physiology*

Substances

  • Ganglionic Blockers
  • Hexamethonium