IMMUNOHISTOCHEMICAL LOCALIZATION OF CYTOCHROME-P450 ENZYMES 2C AND 4AIN THE NORMAL RAT-BRAIN

Objective To localize cytochrome P450 enzymes 4A and 2C in central ner vous cells of normal male rats. Methods Eight drug/alcohol untreated n ormal male rats (150-200 g of body weight) were treated by the optimiz ed perfusion technique, then brain tissues were postfixed, paraffin-em bedded and cut into series sections, which were labeled by the improve d strept-avidin-biotin complex DAB-nickel enhancer (SABC-DAB-Ni) immun ohistochemistry and hematoxylin & eosin (H & E) stain techniques. Resu lts The immunohistochemical results indicated that P450 2C-11 enzyme w as localized in diverse numbers of neurons as well as some neuroglial cells, with focal or defuse distribution in many brain regions such as cerebrum, thalamus, olfactory bulb, hypothalamus, brain-stem, hippoca mpus, cerebellum, interpositus nucleus, caudate-putamen, and globus pa llidus. In contrast, no positive findings of P450 4A-2, 3 and 8 enzyme s were obtained in the same animals. With high magnification, 2C-11 pr otein was able to be roughly observed on the endoplasmic reticulum of the rat neurons. Conclusions P450 2C-11 protein, rather than P450 4A-2 , 3 and 8, may be a candidate of brain P450 enzymes in the normal male rats.