In the present study, the effects of chronic lithium pre-treatment (30 days) on penile erection (PE) induced by bromocriptine were investigated in rats. Intraperitoneal administration of the dopamine receptor agonist, bromocriptine (4-32 mg/kg) induced PE in a biphasic manner. The maximum response was obtained with 8 mg/kg of bromocriptine and the effect was decreased with increasing doses of the drug from 8 to 32 mg/kg. When animals were pre-treated with different doses of the D-1 dopamine receptor antagonist, SCH 23390, or the D-2 dopamine receptor antagonist, sulpiride, the PE response was decreased. The response induced by bromocriptine (4-32mg/kg) was reduced in animals pre-treated with chronic lithium. SCH 23390 did not produce a larger inhibitory effect on the bromocriptine response in animals pre-treated with chronic lithium, but the inhibitory effect of sulpiride was increased in this condition. It is concluded that chronic lithium treatment may alter the D-1/D-2 receptor activity and inhibit bromocriptine-induced PE.
Berendsen H H G, Broekkamp C L F (1987) Drug-induced penile-erection in rats: indication of serotonin 1B receptor mediation. Eur J Pharmacol135: 279-287
2.
Braun A.R., Chase T.N. (1986) Obligatory D-1/D-2 receptor interaction in the generation of dopamine agonist related behaviors. Eur J Pharmacol131 : 301-306
3.
Cavery P.M., Kao L.C., Zhang T.G., Amdur R.L., Lin D.H., Singh R., Klawans H.L. (1990) Dopaminergic alterations in cotreatments attenuating haloperidol-induced hypersensitivity. Pharmacol Biochem Behav32: 291-300
4.
Costall B., Foryune D.H., Hui S C G, Naylor R.J. (1980) Neuroleptic antagonism of the motor inhibitory effects of apomorphine within the nucleus accumbens: drug interaction at presynaptic receptors. Eur J Pharmacol63: 347-358
5.
Creese I., Leff S.E., Sibleg D.R., Hamblin M.W. (1984) Radioligand binding studies of agonist interactions with dopamine receptors. In Poste G, Crooke S T (eds), Dopamine receptor agonist . Plenum Press, New York, pp. 23-64
6.
Dehpour A.R., Samini M., Sharifzadeh M., Hasan-Mazandarani H. (1995) Effect of chronic lithium pretreatment on apomorphine-induced penile erection. Gen Pharmacol26: 1015-1020
7.
Di Chiara G., Porceddu M.L.,Vargiu L., Argiolas A., Gessa G.L. (1976) Evidence for dopamine receptors mediating sedation in mouse brain. Nature264: 564-567
8.
Dorce V.A., Palermo-Neto J. (1992) Lithium effects on estrogen-induced dopaminergic supersensitivity in rats. Brain Res Bull29: 239-241
9.
Foreman M.M., Hall J.L. (1987) Effects of D-2-dopaminergic receptor stimulation on male rat sexual behavior. J Neural Transm68: 153-170
10.
Gower A.J., Berendsen H H G, Princen M.M., Broekkamp C L E (1984) The yawning-penile erection syndromes as a model for putative dopamine autoreceptor activity. Eur J Pharmacol103: 81-87
11.
Hallcher L.M., Sherman W.R. (1980) The effects of lithium ion and other agents on the activity of myo-inositol-1-phosphatase from bovine brain. J Biol Chem225:10896-10901
12.
Hull E.M., Eaton R.C., Markowski V.P., Moses J., Lumley L.A., Loucks J.A. (1992) Opposite influence of medial preoptic D-1 and D-2 receptors on genital reflexes: implication for copulation. Life Sci51:1705-1713
13.
Hyttel J. (1984) Functional evidence for selective dopamine D-1 receptor blockade by SCH 23390. Neuropharmacology23: 1395-1401
14.
Iorio L.C., Barnett A., Leitz F.H., House V.P., Korduba C.A. (1983) A potential benzazepine antipsychotic with unique interactions on dopaminergic system. J Pharmacol Exp Ther226: 462-468
15.
Jackson D.M., Jenkins O.F., Ross S.B. (1988) The motor effects of bromocriptine—a review . Psychopharmacology95: 433-446
16.
Kanba S., Pfenning M., Richelson E. (1985) Lithium ions inhibit function of low but not high-affinity muscarinic receptor of murine neuroblastoma cells (clone N1E-115). Psychopharmacology86: 413-416
Kendler K.S., Bracha H.S., Davis K.L. (1982) Dopamine autoreceptor and post-synaptic receptor blocking potency of neuroleptics. Eur J Pharmacol79: 217-223
19.
Leff S.E., Creese I. (1985) Interactions of dopaminergic agonists and antagonists with dopaminergic D-3 binding sites in rat striatum. Mol Pharmacol27:184-192
20.
Melis M.R., Argiolas A., Gessa G.L. (1987) Apomorphine-induced penile erection and yawning: site of action in brain. Brain Res415: 98-104
21.
Nahorzki S.R., Ragan C.I., Challiss R A J (1991) Lithium and the phosphoinositide cycle: an example of uncompetitive inhibition and its pharmacological consequence. Trends Pharmacol Sci12: 297-303
22.
Pert A., Rosenblatt J.E., Sivit C., Pert C.B., Bunney W.E. (1978) Longterm treatment with lithium prevents the development of dopamine receptor supersensitivity. Science201:171-173
23.
Saiani L., Trabucchi M., Tonon G.C., Spano P.F. (1979) Bromocriptine and lisuride stimulate the accumulation of cyclic AMP in intact slices but not in homogenates of rat neostriatum. Neurosci Lett14: 31-36
24.
Scatton B., Fage D., Oblin A., Zivkovic B., Arbillas S., Langer S.Z., Bartholini G. (1985) Influence of GABA mimetics and lithium on biochemical manifestations of striatal dopamine target cell hypersensitivityPsychopharmacology2 (Suppl): 39-45
25.
Stoof J.C., Kebabian J.W. (1984) Two dopamine receptors: biochemistry, physiology, pharmacology. Life Sci35: 2281-2296
26.
Valler L., Muca C., Magni M., Albert P., Bunzow J., Meldolesi J., Cirellio O. (1990) Differentiate coupling of dopaminergic D-2 receptors expressed in different cell types. J Biol Chem265: 10320-10326
27.
Wood A.J., Goodwin G.M. (1987) A review of the biochemical and neuropharmacological actions of lithium. Psychol Med77: 579-600
