Hronično unošenje hlorpromazina izaziva inhibiciju intracelularne biohemijske aktivnosti moždanog tkiva miša

Abstract

Chlorpromazine (CPZ), an antipsychotic drug, was found to inhibit intracellular carboxylesterases (CarbEs). As intracellular target carboxylesterases we used alpha-naphthyl acetate esterase (alpha-NA), naphthol AS-D chloroacetate esterase (AS-D) and alpha-naphthyl butyrate esterase (alpha-NB) in mouse polymorphonuclear neutrophils (PMN), hepatocytes (HC) and neuronal brain cells (NC). The impact of CPZ on the cells ranged from no effect to death, with intermediary effects of decreased CarbEs activities without either morphological changes or structural changes. The results of our study indicate that intracellular CarbEs activity inhibition by CPZ was dose-dependent, though the drug concentration required to bring about 50% inhibition of the initial activity (ID-50) varied between the mouse cell types, under the same experimental conditions. CarbEs activity was decreased or completely inhibited at CPZ concentrations ranging from 0.5 to 5.0 mg/ml (1.4 to 14.08 mmol/l). The impact maximum concentration of CPZ 5 mg/ml (14.08 mmol/l) on mouse brain cells resulted in 46.58% inhibition for AS-D, 54.26% for α-NA and 99.52% for α-NB. Our studies established a clear relationship between the increasing concentrations of CPZ and the extent of inhibition of the intracellular esterases of mice. Correlation of the inhibitory effects in all the cell types was demonstrated. The polymorphonuclear neutrophils - leukocytes were the most sensitive (ID-50 = 0.42 mg CPZ/ml) and the hepatocytes most resistant to the CPZ effect (ID-50 = 2.45 mg CPZ/ml). Since leukocytes are human cells much more readily available than hepatocytes or neuronal cells, we presume that CarbEs in peripheral blood leukocytes could be used as markers for the indication of intracellular biochemical damage of hepatocytes and neuronal brain cells by CPZ.

Hlorpromazin (CPZ) je neuroleptik koji se koristi za dugotrajni tretman najtežih psihijatrijskih bolesti. Osnovni mehanizam dejstva CPZ je blokada D2 receptora ali se malo zna o efektima CPZ na intracelularnu biohemijsku aktivnost moždanog tkiva. U ovom radu ispitivan je uticaj CPZ-a na intracelularne karboksilesteraze (EC 3.1.1.1.), kao marker biohemijske aktivnosti. Primenom osetljive in vitro metode - MIMDECI detektovane su rane intracelularne biohemijske promene u morfološki očuvanim ćelijama, indukovane primenom CPZ-a. MIMDECI je tehnologija koja koristi dva markera (za enzimsku aktivnost i morfologiju ćelija) i meri delovanje leka na enzim pre pojave nespecifičnog oštećenja ćelija. Intracelularna biohemijska aktivnost praćena je pomoću alfa-naftil acetat karboksilesteraze, naftol AS-D hloroacetat karboksilesteraze i alfa-naftil butarat karboksilesteraze. Karboksilesteraze su citoplazmatski konstituenti mnogih tipova ćelija, tako da su paralelno praćeni efekti CPZ-a u polimorfonuklearima periferne krvi, hepatocitima i nervnim ćelijama mozga sivog miša, u in vitro uslovima. Naši rezultati ukazuju da CPZ inhibira karboksilesteraze u sva tri tipa ćelija i da stepen inhibicije zavisi od vremena aplikacije i primenjene koncentracije. Intraceiularna kar boksiiesterazna aktivnost je smanjena ili potpuno inhibirana primenom CPZ-a u rastućim koncentracijama od 0.5 - 5.0 mg/ml. Korelacijom inhibitornog efekta u sva tri tipa ćelija ustanovili smo da su polimorfonuklearni leukociti periferne krvi najosetljiviji na dejstvo CPZ-a (ID50 = 0.42 mg/ml) dok su hepatociti najrezistentniji (ID50 = 2.45 mg/ml).