INTERACTIVE EFFECTS OF DIFFERENT DURATION OF LITHIUM PRETREATMENT WITH AMIKACIN AND GENTAMICIN ONAPOMORPHINE-INDUCED LICKING IN RATS

In this study the hypothesis that aminoglycoside antibiotics and lithium may influence apomorphine-induced licking via their effects on phosphoinositide pathways and calcium stores were investigated in male rats. Subcutaneous administration of apomorphine (0.1,0.25 and 0.5 mg/kg) to rats induced licking in a dose-dependent manner and the maximum response was obtained by the dose of 0.5 mg/kg of the drug. Intracerebroventricular injections of amikacin (5, 25 and 50 ug/rat) and gentamicin (10, 20 and 40 ug/rat) decreased the apomorphine-induced licking significantly. Pretreatment of animals with lithium (600 mg/1) for 7,14 and 21 days increased licking induced by apomorphine. The inhibitory effects of amikacin and high dose of gentamicin were not affected by lithium pretreatment for 14 and 28 days. These findings indicate the possible involvement of phosphoinositide cascade in alterations of apomorphine-induced licking by aminoglycoside antibiotics and lithium in the brain. Also it is suggested that type and dose of aminoglycoside antibiotics and duration of lithium administration probably have different effects on responses mediated by phosphoinositide hydrolysis.