Differential effect of short- and long-term lithium treatment on m-CPP-induced neuroendocrine changes in rats.
Intravenous administration of the serotonergic agent m-chlorophenylpiperazine (m-CPP) to rats produced increases in plasma prolactin and corticosterone and a decrease in plasma growth hormone concentrations. Short-term (2-4 days) and long-term (21-23 days) lithium treatment did not affect baseline levels of prolactin, corticosterone or growth hormone. Long-term lithium treatment accentuated m-CPP's effect on plasma prolactin and corticosterone but not on growth hormone levels. On the other hand, short-term lithium treatment attenuated m-CPP's effect on plasma corticosterone but not on plasma prolactin or growth hormone levels. These findings demonstrate a differential effect of the duration of lithium treatment on m-CPP-induced neuroendocrine changes. One possible explanation for this differential effect may be that different 5-HT receptor subtypes are involved in mediating different neuroendocrine functions and, furthermore, these different 5-HT receptor subtypes may be affected differentially following lithium treatment. Alternatively, lithium-induced changes in other neurotransmitter systems may be responsible for this differential effect.
Aulakh
C S
CS
Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, Md. 20892.
Hill
J L
JL
Murphy
D L
DL
D000818:Animals; D003345:Corticosterone / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D008094:Lithium / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D009490:Neurosecretory Systems / Q000187:drug effects*; D010879:Piperazines / Q000494:pharmacology*; D011388:Prolactin / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013997:Time Factors
D010879:Piperazines; D017366:Serotonin Receptor Agonists; D011388:Prolactin; D013006:Growth Hormone; D008094:Lithium; C015068:1-(3-chlorophenyl)piperazine; D003345:Corticosterone