Aulakh C S, Zohar J, Wozniak K M, Hill J L, Murphy D L
Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, MD 20892.
Eur J Pharmacol. 1988 Jun 10;150(3):239-46. doi: 10.1016/0014-2999(88)90004-0.
Intravenous administration of the 5-HT1B agonist, m-chlorophenylpiperazine (m-CPP) to rats produced increases in plasma prolactin (peak effect at 15 min), corticosterone (peak effect at 30 min) and a decrease in plasma growth hormone (peak effect at 15 min) concentrations. Short-term or long-term clorgyline treatment did not affect baseline levels of prolactin, corticosterone or growth hormone. Short-term clorgyline treatment attenuated m-CPP's effect on corticosterone but not on prolactin or growth hormone. On the other hand, long-term clorgyline treatment attenuated m-CPP's effect on prolactin but not on corticosterone or growth hormone. These findings are compatible with development of functional subsensitivity of 5-HT1B receptors mediating prolactin release following long-term clorgyline treatment. Attenuation of m-CPP's effect on corticosterone following short-term clorgyline treatment suggests either early adaptational changes in a 5-HT receptor subtype mediating corticosterone release, or clorgyline-induced increases in other neurotransmitters such as norepinephrine which may be responsible for attenuating m-CPP's effect on corticosterone.
