ALTERATIONS OF STRIATAL MONOAMINE METABOLITES IN YOUNG-RATS FOLLOWINGPRENATAL AND POSTNATAL LEAD-EXPOSURE

Dam rats were given lead (0, 0.58, 1.76, and 5.27 mmol/l) containing w ater ad lib from day 16 of gestation to weaning of the offspring on da y 21 postpartum. The pups continued drinking the same lead containing water until the postnatal day 30. At the 30th day postpartum, the pups in each lead treated group were divided into four groups. The first g roup contains six male pups (PN30M). The second, third, and fourth gro ups contain six female pups (PN30F, PN60a, PN60b), respectively. The s ix female pups from control group formed the fifth group (PN60c). PN60 a continued drinking the same lead-containing water until the postnata l day 60. PN60b were dosed with distilled water instead of lead-contai ning water from the 30th day to the 60th day postpartum. PN60c began t o expose to 5.27 mmol Pb/l from the 30th day to the 60th day postpartu m. The rats in PN30M and PN30F were decapitated on the 30th day postpa rtum, whereas PN60a, PN60b, and PN60c were decapitated on the 60th day postpartum. The contents of metabolites of monoamine neurotransmitter s: homovanillic acid (HVA), dihydroxyphenylacetic acid (DOPAC), 3-meth oxy-4-hydroxyphenylglycol (MHPG), and 5-hydroxyindoleacetic acid (5-HI AA) in striatum were determined using high performance liquid chromato graphy with electrochemical detection (HPLC-ECD). There were significa nt increases in the concentrations of HVA (1.58 +/- 0.30 vs. 1.17 +/- 0.12 ng/mg wet tissue in the 5.27 mmol Pb/l group of PN30M, p < 0.01; and 1.44 +/- 0.08 vs. 1.17 +/- 0.10 ng/mg wet tissue in the 5.27 mmol Pb/l group of PN60a, p < 0.05) and DOPAC (2.39 +/- 0.25, 2.47 +/- 0.28 , 2.39 +/- 0.44 vs. 1.82 +/- 0.24 ng/mg wet tissue in three lead treat ed groups of PN60a, p < 0.05). The significant decreases in the concen tration of MHPG (37.33 +/- 5.53, 32.02 +/- 6.87, 33.31 +/- 2.41 vs. 43 .85 +/- 4.93 ng/mg wet tissue in the 0.58 mmol Pb/l group of PN60a, p < 0.05; in the 1.76 and the 5.27 mmol Pb/l group of PN60a, p < 0.01) a nd 5-HIAA (0.23 +/- 0.04 vs. 0.38 +/- 0.05 ng/mg wet tissue in the 5.2 7 mmol Pb/l group of PN30M, p < 0.05; 0.26 +/- 0.09 vs. 0.45 +/- 0.09 ng/mg wet tissue in the 5.27 mmol Pb/l group of PN30F, p < 0.05; 0.31 +/- 0.08 vs. 0.44 +/- 0.08 ng/mg wet tissue in the 5.27 mmol Pb/l grou p of PN60a, p < 0.05) were observed. No significant changes in the con centration of monoamine metabolites were observed either in rats of PN 60b or PN60c. The results demonstrated the disturbances of monoamine m etabolism in the striatum of developmental lead exposed rats.