The effect of chronic lithium treatment on rat pineal N-acetyltransferase rhythm.
Lithium chloride administration to rats for 5 weeks caused a significant decrease in dark-induced activity of rat pineal N-acetyltransferase (E.C.2.3.1.5.). This effect is not observed after 3 days or 3 weeks of treatment. Furthermore, chronic lithium treatment suppressed the amplitude and may have delayed the peak of the diurnal cycle of N-acetyltransferase activity. In vitro, various concentrations of lithium chloride (2, 4 and 10 microM) did not affect N-acetyltransferase activity. Beta adrenergic receptor binding studies with [3H]dihydroalprenolol indicated a decrease in number of pineal beta adrenergic receptors in rats treated chronically with lithium. These results are consistent with a lithium-induced subsensitivity of pineal beta adrenergic receptors and may explain the effect of lithium on pineal-mediated cyclic behaviors.
D000123:Acetyltransferases / Q000378:metabolism*; D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D004082:Dihydroalprenolol / Q000378:metabolism; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D010870:Pineal Gland / Q000187:drug effects* / Q000201:enzymology; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D012965:Sodium Chloride / Q000494:pharmacology; D013997:Time Factors
D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D012965:Sodium Chloride; D004082:Dihydroalprenolol; D008094:Lithium; D000123:Acetyltransferases