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.
Teranishi
Y
Y
Department of Physiology, Hiroshima University, Faculty of Medicine, Japan. ytera@mcai.med.hiroshima-u.ac.jp
Iida
N
N
Ishioka
N
N
Sugino
H
H
Amano
T
T
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