Involvement of beta-adrenergic systems in the antagonizing effect of paeoniflorin on the scopolamine-induced deficit in radial maze performance in rats.
Paeoniflorin, a major constituent of peony root, has been demonstrated to attenuate the radial maze performance deficit produced by scopolamine. In the present study, to investigate the possible involvement of beta-adrenergic systems in the paeoniflorin antagonism of the scopolamine deficit, the effects of two beta-adrenoceptor antagonists, propranolol and atenolol, on the paeoniflorin effect were examined in male Wistar rats. Paeoniflorin (1 mg/kg, p.o.) significantly attenuated the scopolamine HBr (0.3 mg/kg, i.p.)-induced deficit in the choice accuracy in radial maze performance without changing the running time prolonged by scopolamine. Neither D,L-propranolol HCl, a lipophilic beta-antagonist, at 3 mg/kg, i.p. nor atenolol, a hydrophilic beta 1-antagonist that is known to hardly ever cross the blood-brain barrier, at 1 mg/kg, i.p. impaired maze performance by itself or aggravated the scopolamine-induced deficit in radial maze performance. Both antagonists, however, completely blocked the antagonizing effect of paeoniflorin on the scopolamine deficit. These data suggest that the beta-adrenergic systems, especially peripheral beta 1-adrenergic systems, are involved in the antagonizing effect of paeoniflorin on the scopolamine deficit in radial maze performance in rats.
Ohta
H
H
Section of Pharmacology, Research Institute for Wakan-Yaku, Toyama, Japan.
Matsumoto
K
K
Watanabe
H
H
Shimizu
M
M
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001262:Atenolol / Q000494:pharmacology; D001565:Benzoates; D001952:Bridged-Ring Compounds; D005960:Glucosides / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects; D039821:Monoterpenes; D011433:Propranolol / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism*; D018342:Receptors, Adrenergic, beta-1 / Q000187:drug effects; D012601:Scopolamine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D006027:Glycosides
D000894:Anti-Inflammatory Agents, Non-Steroidal; D001262:Atenolol; D001565:Benzoates; D001952:Bridged-Ring Compounds; D005960:Glucosides; D039821:Monoterpenes; D011433:Propranolol; D011943:Receptors, Adrenergic, beta; D018342:Receptors, Adrenergic, beta-1; D012601:Scopolamine; C015423:peoniflorin; D006027:Glycosides