title: Effects of clonidine and BS 100-141 on the EEG sleep pattern in rats.
abstract: The effects of the peripheral and central alpha-adrenoceptor stimulant and antihypertensive agents clonidine and BS 100-141 (N-amidino-2[2,6-dichlorophenyl]acetamide - HCl) on EEG sleep patterns in rats and on blood pressure in pithed rats have been investigated. Whereas both compounds abolished paradoxical sleep (PS), clonidine, in contrast to BS 100-141, markedly increased the sleeping time. Both drugs caused a dose-dependent increase in the blood pressure of pithed rats. The pressor action was abolished by the alpha-adrenoceptor blocking agent phentolamine, but was not influenced by reserpine, indicating a direct stimulation of vascular alpha-adrenoceptors by both drugs. It is suggested that sedation or sleep induction by adrenergic drugs cannot be explained exclusively by an action on central alpha-adrenoceptors. Rather, the findings suggest that such an action may be involved in the modulation of PS.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology*; D004569:Electroencephalography; D005260:Female; D006146:Guanidines / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D010648:Phenylacetates / Q000494:pharmacology*; D051381:Rats; D012110:Reserpine / Q000494:pharmacology; D012890:Sleep / Q000187:drug effects* / Q000502:physiology; D013116:Spinal Cord / Q000502:physiology; D014628:Vagotomy
chemical_list: D000316:Adrenergic alpha-Agonists; D000959:Antihypertensive Agents; D006146:Guanidines; D010648:Phenylacetates; D012110:Reserpine; D003000:Clonidine; D010646:Phentolamine