Is compensatory vasoconstrictor tone in the hindquarter vascular region induced by hemorrhage in conscious spontaneously hypertensive rats?
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.
Department of Physiology, Hiroshima University, Faculty of Medicine, Japan. ytera@mcai.med.hiroshima-u.ac.jp
Y
Y
Teranishi
N
N
Iida
N
N
Ishioka
H
H
Sugino
T
T
Amano
D000818:Animals; D001012:Aorta, Abdominal; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D003243:Consciousness; D005730:Ganglionic Blockers / Q000494:pharmacology; D006470:Hemorrhage / Q000503:physiopathology*; D018738:Hexamethonium / Q000494:pharmacology; D006614:Hindlimb / Q000098:blood supply*; D007022:Hypotension / Q000503:physiopathology; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000502:physiology*
D005730:Ganglionic Blockers; D018738:Hexamethonium