Multiple roles of nucleus reticularis gigantocellularis in physiologic and pharmacologic regulation of cardiovascular functions.
This communication summarizes results from our laboratory during the past few years indicating that the nucleus reticularis gigantocellularis (NRGC) in the medulla oblongata plays an active role in the physiologic and pharmacologic regulation of cardiovascular functions. Apart from directly eliciting hypotension and cardioinhibition, the NRGC also assumes a modulatory role on the baroreceptor reflexes. Some gigantocellular reticular neurons exhibit electrophysiologic properties of cardiovascular neurons (neurons that alter their discharge frequencies in response to arterial pressure fluctuations), while others manifest cardiac rhythm-related activities. Pharmacologically, this reticular nucleus may be engaged by the centrally-acting antihypertensive agent, clonidine (Catapres, Boehringer Ingelheim), to produce hypotension and bradycardia. It may also participate in the cardiovascular suppressive effects of morphine and endogenous opioid peptides.
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D002320:Cardiovascular Physiological Phenomena; D002319:Cardiovascular System / Q000187:drug effects / Q000294:innervation; D002415:Cats; D003000:Clonidine / Q000494:pharmacology; D004594:Electrophysiology; D007022:Hypotension / Q000503:physiopathology; D008526:Medulla Oblongata / Q000166:cytology / Q000502:physiology*; D009020:Morphine / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology; D009474:Neurons / Q000502:physiology; D011311:Pressoreceptors / Q000502:physiology; D051381:Rats; D012018:Reflex / Q000502:physiology
D000959:Antihypertensive Agents; D009294:Narcotics; D009020:Morphine; D003000:Clonidine