Central sympathetic control of spinal endothelin release in the rat.
Endothelin and its receptors have been identified in the spinal cord. Intrathecal administration of endothelin-3 produces hypotension in anesthetized rats. The present study was designed to identify whether endothelin-3 is released upon changes in sympathetic nervous activity. Endothelin-3-like immunoreactivity in spinal superfusates was directly correlated with resting arterial pressure. Endothelin-3 levels were enhanced by hypothalamic stimulation and by hemorrhage-induced hypotension and reduced by nitroprusside-induced hypotension. These findings suggest that sympathetic activation enhances endothelin-3 release but that nitroprusside may act directly to suppress release. We propose that endothelin-3 plays a role in spinal regulation of sympathetic outflow.
Knuepfer
M M
MM
Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, MO 63104.
O'Brien
D
D
Hoang
D
D
Gan
Q
Q
Song
C
C
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004558:Electric Stimulation; D016232:Endothelins / Q000378:metabolism*; D007031:Hypothalamus / Q000502:physiology; D007278:Injections, Spinal; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000502:physiology*
D016232:Endothelins; D009599:Nitroprusside; D010656:Phenylephrine