title: Beta-1 adrenoceptor antagonists potentiate the anticonvulsive effect of swim stress in mice.
abstract: To explore the possible involvement of beta adrenoceptor antagonists in the previously observed anticonvulsive effect of swim stress, the mice were, prior to administration of convulsants, pre-treated with propranolol (a non-selective beta adrenoceptor antagonist), betaxolol (a selective beta-1 adrenoreceptor antagonist), or ICI 118,551 (a selective beta-2 adrenoreceptor antagonist). In control unstressed animals, only propranolol [10 mg/kg, intraperitoneally (ip)] produced a significant change. It enhanced the threshold dose of picrotoxin producing tonic hindlimb extension. However, in swim-stressed animals, propranolol enhanced doses of picrotoxin producing tonic hindlimb extension and death, while betaxolol (20 mg/kg, i.p.) enhanced doses of picrotoxin producing running/bouncing clonus, tonic hindlimb extension and death. Pre-treatment with ICI 118,551 (4 mg/kg, i.p.) failed to affect doses of picrotoxin producing convulsions and death. The results demonstrate that blockade of beta-1 adrenoceptors potentiates the anticonvulsant effect of swim stress against convulsions produced by picrotoxin, a noncompetitive GABA(A) receptor antagonist.
authors.affiliation: Laboratory for Molecular Neuropharmacology, Division of Molecular Medicine, Ruder Boskovic Institute, PO Box 180, 10002, Zagreb, Croatia. pericic@rudjer.irb.hr
authors.forename: D
authors.initials: D
authors.lastname: Pericic
authors.forename: M
authors.initials: M
authors.lastname: Jazvinscak
authors.forename: D
authors.initials: D
authors.lastname: Svob
authors.forename: K
authors.initials: K
authors.lastname: Mirkovic
mesh_terms: D058671:Adrenergic beta-1 Receptor Antagonists; D000818:Animals; D015784:Betaxolol / Q000494:pharmacology; D003292:Convulsants; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D010852:Picrotoxin; D011412:Propanolamines / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D018342:Receptors, Adrenergic, beta-1 / Q000502:physiology; D012640:Seizures / Q000139:chemically induced / Q000401:mortality; D013312:Stress, Physiological; D013550:Swimming
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D015784:Betaxolol; D003292:Convulsants; D010852:Picrotoxin; D011412:Propanolamines; D011433:Propranolol; D018342:Receptors, Adrenergic, beta-1; C026777:ICI 118551