Behavioral and receptor binding studies of phencyclidine (PCP) and lithium interaction in the rat.
Three groups of female Sprague-Dawley rats (n = 4) were conditioned to drink water during a daily 2 hr session. The water was then changed to a solution of 1.0 mg/ml lithium chloride producing average doses between 62.9 and 72.1 mg/kg/day for Groups I and II. These rats were challenged with 4 mg/kg PCP i.p. before and during lithium treatment. Group I was tested for spontaneous locomotor activity in the open field apparatus. Lithium alone did not affect activity. After 1, 2, and 3 weeks of chronic lithium, PCP-induced activity increased 2.1, 1.7, and 2.8 fold, respectively, relative to PCP-induced activity during limited access to water only. Whole brain homogenates from Group II, after one week of chronic lithium, were used for receptor binding experiments using [3H] PCP; Group III served as water controls. The Kd (nM +/- S.E.M.) was not different in untreated (146.39 +/- 18.95) and lithium-treated (181.22 +/- 14.35) rats. The Bmax (pmole/mg protein +/- S.E.M.), however, was increased 48% (p less than 0.01) from 1.50 +/- 0.08 to 2.22 +/- 0.10 after lithium. These preliminary results suggest that chronic administration of lithium modifies the behavioral effects of PCP possibly via alterations at the receptor level.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004347:Drug Interactions; D005260:Female; D007700:Kinetics; D008094:Lithium / Q000097:blood / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D010622:Phencyclidine / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000378:metabolism*; D017478:Receptors, Phencyclidine
D017981:Receptors, Neurotransmitter; D017478:Receptors, Phencyclidine; D008094:Lithium; D010622:Phencyclidine