1 The blood pressure of conscious normotensive, Goldblatt-hypertensive and genetichypertensive 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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.