Differential expression of androgen and estrogen receptors in PCB (Aroclor 1254)-exposed rat ventral prostate: impact of alpha-tocopherol.

Polychlorinated biphenyls (PCBs) are environmental toxicants, which affect male fertility by altering the androgen and estrogen levels. PCB-induced toxic manifestations are associated with the production of reactive oxygen species. Vitamin E (α-tocopherol) is a major lipophilic chain breaking antioxidant, which protects polyunsaturated fatty acids in tissues against peroxidation, a property that could be beneficial in the male reproductive biology. The purpose of this study was to determine the impact of α-tocopherol on PCB (Aroclor 1254)-induced changes in androgen receptor (AR) and estrogen receptors (ERs) expression in Wistar rat ventral prostate. Rats were divided into 3 groups of 6 animals each. Group I rats were administered corn oil (vehicle) intraperitoneally (i.p.); Group II rats were treated with 2 mg kg(-1)day(-1) of PCB (i.p.); Group III rats were treated with 2 mg kg(-1)day(-1) of PCB (i.p.) along with simultaneous oral supplementation of 50 mg kg(-1)day(-1) of α-tocopherol. Serum testosterone and estradiol titers were assayed. Prostatic acid phosphatase activity (PAcP), citric acid concentration, generation of hydrogen peroxide (H(2)O(2)) and lipid peroxides (LPO) were estimated. mRNA and protein expression of AR, ER-α and ER-ß in ventral prostate were quantified. Serum testosterone, estradiol, PAcP, citric acid levels, AR and ER-α expressions were significantly decreased while H(2)O(2) generation, LPO, ER-ß were increased in PCB-exposed animals. Simultaneous supplementation of α-tocopherol in PCB-exposed rats resulted in significant restoration of all the parameters to the control. The results suggest that α-tocopherol has definite protective effect against PCB-induced toxicity in ventral prostatic dysfunction.

Effect of unilateral motor cortex ablation on activity of choline acetyltransferase and levels of amino acid transmitter candidates in the spinal cord of adult monkeys.

Evidence that L-glutamate is a neurotransmitter of corticofugal fibers was sought by measuring changes in several biochemical markers of neurotransmitter function in discrete regions of spinal cord after ablation of sensorimotor cortex in monkeys. One and five weeks after unilateral cortical ablation, samples from six areas of spinal cord (ventral, lateral and dorsal regions of the left and right sides) were analysed for choline acetyltransferase (ChAT) activity and contents of amino acid transmitter candidates-glutamic acid (Glu), aspartic acid (Asp), glycine (Gly), taurine (Tau) and gamma-aminobutyric acid (GABA). During one to five weeks after unilateral cortical ablation of the monkey, prolonged hemiplegia in the contralateral side was observed. Histological examination of the spinal cord 5 weeks after unilateral (left) cortical ablation showed no apparent change in either control (ipsilateral, left) or affected (contralateral, right) sides of the cord as examined by the Klüver-Barrera method. The ChAT activity as a cholinergic marker was scarcely changed in any region of either left (control) or right (affected) side of the spinal cord at one and five weeks after unilateral (left side) ablation of the motor cortex. Amino acid levels in each region of the spinal cord were not significantly changed one week after unilateral ablation of the motor cortex. However, a significant decrease of Glu content was observed in the lateral column of the affected (right) side compared to the control (left) side of cervical and lumbar cord five weeks after cortical ablation of the left motor area. No concomitant alterations of other amino acids were detected.(ABSTRACT TRUNCATED AT 250 WORDS)