Sympathetic blockade significantly improves cardiovascular alterations immediately after spinal cord injury in rats.
Immediately after an experimental spinal cord injury (SCI) in rats, there is a large fall in mean arterial pressure (MAP) and heart rate (HR), followed by an abrupt increase in MAP. To better understand the mechanism involved in these early cardiovascular alterations, we tested the effect of treatment with ganglionic and sympathetic blockers in anesthetized rats subjected to T-5 SCI. Fall in MAP was partially diminished by propranolol and pentolinium, while increase in MAP was abolished by propranolol and pentolinium. Adrenalectomy did not diminish the fall in MAP and HR, however, the increase in MAP was significantly reduced. Likewise, propranolol and pentolinium completely abolished the effects in HR. These data suggest that the early cardiovascular alterations secondary to SCI results from an increased parasympathetic activity and a sympathetic withdrawal.
Bravo
G
G
Departamento Farmacobiología, CINVESTAV, IPN, Calzada de los Tenorios 235, Col. Granjas Coapa, 14330 Mexico D.F., Mexico. gbravof@prodigy.net.mx
Hong
E
E
Rojas
G
G
Guízar-Sahagún
G
G
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001340:Autonomic Nerve Block; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects*; D005730:Ganglionic Blockers / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D008297:Male; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D010425:Pentolinium Tartrate / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology*
D000319:Adrenergic beta-Antagonists; D005730:Ganglionic Blockers; D010425:Pentolinium Tartrate; D011433:Propranolol