title: Central hypotensive action of bridge analogues of clonidine.
abstract: The experimental compounds St-1913, St-1966 and St-1967 in which the bridging nitrogen atom, as found in clonidine, has been replaced by a methylene (--CH2--) function, an oxygen or a sulphur atom, respectively, have been investigated with respect to their acute hypotensive effects in anaesthetized cats. Attention was paid to a possible contribution of the central nervous system to the hypotensive action of the drugs by means of vertebral arterial infusions. Although less active than clonidine, St-1913 and St-1967 are centrally acting hypotensive drugs. Central alpha-adrenoceptors are presumably involved in a similar manner as in the mechanism of clonidine. The hypotensive potency of St-1966 was much lower compared to the aforementioned drugs. A central origin for its depressor effects could be established. However, central alpha-adrenoceptors probably do not participate. In spite of its structural similarity with clonidine the mechanism of action of St-1966 appears to be different.
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents; D002415:Cats; D002490:Central Nervous System / Q000187:drug effects*; D003000:Clonidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D003000:Clonidine