title: Cyclic nucleotides and central cardiovascular control in the conscious cat.
abstract: When infused into the third ventricle of the brain of the conscious cat, the phosphodiesterase inhibitors, papaverine and aminophylline, increased blood pressure and heart rate whilst the phosphodiesterase stimulator, imidazole-4'-acetic acid, decreased blood pressure. Administered intravenously, these compounds caused the opposite effects indicating that the responses after third-ventricular administration were centrally mediated. Infused of dibutyryl cyclic 3',5'-AMP into the third ventricle increased blood pressure and heart rate, whereas dibutyryl cyclic 3',5'-GMP had little effect and antagonised and pressor response to dibutyryl cyclic 3',5'-AMP. ATP, 5'-AMP and adenosine induced similar changes to dibutyryl cyclic 3',5'-AMP, although the pressor responses to these compounds were of different onset and/or duration. When administered into the third ventricle both alpha- and beta-adrenoceptor blocking agents reduced the pressor response caused caused by the phosphodiesterase inhibitor, papaverine, given by the same route. These results demonstrate a central effect of adenosine and adenosine nucleotides to raise blood pressure. The possibility of a specific role for cyclic 3',5'-AMP in the central control of blood pressure is discussed.
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001921:Brain / Q000502:physiology*; D003994:Bucladesine / Q000494:pharmacology; D002415:Cats; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004347:Drug Interactions; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D007275:Injections, Intravenous; D007276:Injections, Intraventricular; D008297:Male; D009712:Nucleotides, Cyclic / Q000502:physiology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D009712:Nucleotides, Cyclic; D010726:Phosphodiesterase Inhibitors; D003995:Dibutyryl Cyclic GMP; D003994:Bucladesine