Cardiovascular effects of injection of argipressin into lateral septal nuclei in rats.
Abstract
"AIM:
To determine whether argipressin (Arg) plays a role in central neural control of cardiovascular function by acting on the lateral septal nuclei (LSN).
METHODS:
Measuring mean arterial blood pressure (MAP) and heart rate (HR) responses followed microinjection of Arg into the LSN of rats anesthetized with urethane.
RESULTS:
Arg (100, 200, and 400 ng) injected into the LSN produced a dose-dependent hypertension and tachycardia. Maximal changes of MAP were 0.9 +/- 0.6, 2.3 +/- 1.3, 4.0 +/- 1.4 kPa, respectively; maximal changes of HR were 12 +/- 27, 50 +/- 33, and 89 +/- 27 bpm, respectively. Pretreatment of the LSN with a vasopressin 1 type antagonist d (CH2)5Tyr(Me) Arg abolished the MAP and HR responses produced by injection of Arg. Peripheral alpha-adrenergic blockade with phentolamine blocked the hypertension responses to injection of Arg into the LSN.
CONCLUSION:
Arg acts in the region of the LSN to exert a central action on the cardiovascular system that is mediates by stimulation of sympathetic outflow.
"
Keywords:
To determine whether argipressin (Arg) plays a role in central neural control of cardiovascular function by acting on the lateral septal nuclei (LSN).
METHODS:
Measuring mean arterial blood pressure (MAP) and heart rate (HR) responses followed microinjection of Arg into the LSN of rats anesthetized with urethane.
RESULTS:
Arg (100, 200, and 400 ng) injected into the LSN produced a dose-dependent hypertension and tachycardia. Maximal changes of MAP were 0.9 +/- 0.6, 2.3 +/- 1.3, 4.0 +/- 1.4 kPa, respectively; maximal changes of HR were 12 +/- 27, 50 +/- 33, and 89 +/- 27 bpm, respectively. Pretreatment of the LSN with a vasopressin 1 type antagonist d (CH2)5Tyr(Me) Arg abolished the MAP and HR responses produced by injection of Arg. Peripheral alpha-adrenergic blockade with phentolamine blocked the hypertension responses to injection of Arg into the LSN.
CONCLUSION:
Arg acts in the region of the LSN to exert a central action on the cardiovascular system that is mediates by stimulation of sympathetic outflow.
"