[Effects of lead exposure on nitric oxide synthase activity in different brain regions of developmental rat].
OBJECTIVE
To observe the influence of lead exposure on the activity of nitric oxide synthase (NOS) in different brain regions of rat.


METHODS
By establishing a series of rat models exposed to different low levels of lead (drinking water containing 0.025%, 0.050%, 0.075% of lead acetate) during developing period, NOS activities in hippocampus, cerebellum, cerebral cortex and brain stem were studied.


RESULTS
On the 21st day after birth, NOS activities in hippocampus of three levels of lead exposed groups [(1.53 +/- 0.20), (1.66 +/- 0.23), (1.88 +/- 0.32) U/mg pro respectively], and in cerebellum [(0.87 +/- 0.24), (0.85 +/- 0.09), (0.91 +/- 0.18) U/mg pro respectively] were significantly lower than those of control group [(2.36 +/- 0.18), (1.41 +/- 0.18) U/mg pro, respectively, P < 0.01]. NOS activities in cerebral cortex of 0.075% group [at 7, 14, 21 d of age [(1.29 +/- 0.14), (1.03 +/- 0.15), (0.69 +/- 0.10) U/mg pro] were significantly lower than those in control group [(2.54 +/- 0.31), (1.64 +/- 0.22), (1.24 +/- 0.14) U/mg pro respectively], and 0.025% group [(2.42 +/- 0.19), (1.59 +/- 0.17), (1.27 +/- 0.12) U/mg pro respectively], and 0.050% group [(2.56 +/- 0.53), (1.77 +/- 0.19), (1.24 +/- 0.10) U/mg pro respectively, P < 0.05]. There were no significant differences among control, 0.025%, and 0.050% groups (P > 0.05). Lead exposure had no influence on NOS activity in brain stem at the same age (P > 0.05).


CONCLUSIONS
NOS activities in hippocampus, cerebellum and cerebral cortex were inhibited by low level lead exposure and the degree of the effect was related to Pb exposure time and/or level of Pb exposed.
Dong
Gui-juan
GJ
Children's Hospital of Medical school of Zhejiang University, Hangzhou 310003, China.
Zhao
Zheng-yan
ZY
Zhu
Zhi-wei
ZW
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D001933:Brain Stem / Q000187:drug effects / Q000201:enzymology; D002531:Cerebellum / Q000187:drug effects / Q000201:enzymology; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology; D007854:Lead / Q000633:toxicity*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D007854:Lead; D019001:Nitric Oxide Synthase