Facilitation of the flexor reflex in the cat by intrathecal injection of catecholamines.
1. Effects of some alpha- and beta-adrenoceptor stimulants and antagonists were investigated on flexor reflex (FR) in chloralosed cats.2. Noradrenaline (NA) produced facilitation of FR which was dose-dependent and reproducible and was blocked by alpha-adrenoceptor blocking agents.3. Strychnine also produced facilitation of FR but the response was unaffected by alpha-adrenoceptor blocking agents.4. Metaraminol and alpha-methyl-noradrenaline had little effect on FR but blocked the NA response.5. beta-adrenoceptor stimulants and antagonists had neither any effect on FR nor modified the NA response.6. Vasopressin and histamine also failed to modify FR.7. Possibility of alpha-adrenoceptors in the neurones integrating FR is suggested.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000494:pharmacology*; D002415:Cats; D006632:Histamine / Q000494:pharmacology; D007278:Injections, Spinal; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D008680:Metaraminol / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D011955:Receptors, Drug; D012018:Reflex / Q000187:drug effects*; D012584:Sciatic Nerve / Q000187:drug effects; D013331:Strychnine / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D002395:Catecholamines; D011955:Receptors, Drug; D014667:Vasopressins; D008680:Metaraminol; D006632:Histamine; D008012:Lidocaine; D013331:Strychnine; D009638:Norepinephrine