Effect of haloperidol on adrenal ornithine decarboxylase activity of the rat.
The administration of the dopamine antagonist haloperidol (HLP) to rats produced a temporary increase in adrenomedullary and cortical ornithine decarboxylase (ODC) activity. The time-course of stimulation of ODC activity by HLP showed different patterns in both structures. Medullary ODC activity was highest at 2.5 h, decreasing at later times; cortical ODC activity was not affected by the drug at 2.5 h, but then increased up to at least 6.5 h. The medullary increase observed at 2.5 h was dose-related and could be prevented by splanchnicotomy. Hypophysectomized rats, on the contrary, showed an enhanced response to HLP. The results suggest that haloperidol-induced increase of adrenomedullary ODC activity is caused by a reflex increase in preganglionic nerve activity, and that the pituitary gland can modulate this response. Cortical ODC response to HLP, as previously demonstrated, is mediated entirely by the hypophysis.
D000302:Adrenal Cortex / Q000201:enzymology; D000311:Adrenal Glands / Q000187:drug effects*; D000313:Adrenal Medulla / Q000201:enzymology; D000818:Animals; D002262:Carboxy-Lyases / Q000378:metabolism*; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D010902:Pituitary Gland / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013153:Splanchnic Nerves / Q000502:physiology
D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; D006220:Haloperidol