title: Hypotensive and vasodilator actions of SK&F 24260, a new dihydropyridine derivative.
abstract: 1 The blood pressure of conscious normotensive, Goldblatt-hypertensive and genetic-hypertensive rats and normotensive dogs was lowered by SK&F 24260 (1,4-dihydro-2,6-dimethyl-4-(2-trifluormethylphenyl)-3,5-pyridinedicarboxylic acid diethyl ester).2 Tachycardia always accompanied the hypotension. In rats propranolol abolished the tachycardia but in dogs there was only a small reduction in the heart rate response.3 In conscious dogs there was an increase in left ventricular output and a marked fall in total peripheral resistance.4 SK&F 24260 dilated resistance vessels in rat hindquarters. Dilatation was caused by doses of SK&F 24260 some 50 times smaller than those of hydrallazine.5 In preparations of cat skeletal muscle and intestinal vascular beds SK&F 24260 selectively dilated resistance vessels in preference to capacitance vessels and resembled hydrallazine rather than papaverine which has no such selectivity.6 Pre-capillary sphincter vessels were also dilated by SK&F 24260. Changes in fluid equilibrium caused by SK&F 24260 were consistent with selective dilatation of resistance vessels.
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D002415:Cats; D003998:Dicarboxylic Acids / Q000494:pharmacology; D004095:Dihydropyridines; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006614:Hindlimb / Q000098:blood supply; D006845:Hydrocarbons, Fluorinated / Q000494:pharmacology; D008297:Male; D008643:Mesentery / Q000098:blood supply; D009132:Muscles / Q000098:blood supply; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D000959:Antihypertensive Agents; D003998:Dicarboxylic Acids; D004095:Dihydropyridines; D006845:Hydrocarbons, Fluorinated; D011725:Pyridines; D014665:Vasodilator Agents; C001040:1,4-dihydro- 2,6-dimethyl-4-(2-(trifluoromethyl)phenyl)-3,5- pyridinedicarboxylic acid diethyl ester