Methamphetamine 과 Chlorpromazine 이 白鼠腦의 Norepinephrine 含量에 미치는 影響에 關한 實驗的 硏究

EFFECTS OF METHAMPHETAMIN E AND CHLORPROMAZINE ON THE CONTENTS OF N OREPINEPHRINE IN RAT BRAINS

This experimental study was aimed at the effects of methamphetamine and chlorpromazine on brain norepinephrine levels and their interaction on central norepinephrine in Fischer albino rats. Drugs were injected twice daily by intraperitoneal route to groups of rats weighing 150—250g for 5 days. Groups of rats were 25 control rats, 6 rats treated with methamphetamine in low dose (3. 5mg/kg twice daily ), 6 rats treated with methamphetamine in low dose (7mg/kg twice daily), 13 rats treated with methamphetamine in high dose (10mg/kg twice daily), 15 rats treated with chlorpromazine (8mg/ kg twice daily) and 14 rats treated with combined drugs. The rats were sacrificed by decapitation one hour after last injection and brain levels of norepinephrine were assayed fluorometrically by the method of Bertler, Carlsson and Rosengren. The average value of norepinephrine in controlrats was 0. 235 j«g/l g brain and had no sexual difference. Low doses of methamphetamine had little or no effect on brain norepinephrine levels but norpinephrine level was depleted to 50ᅳ60% of the control level after large dose of methamphetamine for 2days. Generally, rats treated with chlorpromazine did not significantly alter norepinephrine levels. Rats treated with methamphetamine (10 mg/kgtwice daily) and chlorpromazine (8 mg/kg twice daily) had higher norepinephrine level than methamphetamine- treated rats, but lower than chlorpromazine- treated rats. Norepinephrine level was depleted after combined treatment for 4 days and no further depletion after treatment for 5 days. The results were discussed in terms of implication for several mechanisms of methamphetamine interaction with chlorpromazine, primarily mediated by cyclic AMP and calcium ion on release of csntral norepinephrine.