Relationships among plumbum,activity of protein kinase C in the brain tissue of fetal mice and changes of memory function

Weijian HOU; Liguang SUN; Qiwen ZHU; Zhe WU; Suyuan LIU; Wei XING

ABSTRACT

BACKGROUND:

Whether plumbum(Pb) exposure induced learning and memory disorder in animals is correlated with the changes of the activity of protein kinase C(PKC) in the brain tissue?

OBJECTIVE:

To investigate the alterative rules of PKC activity in the brain tissue of rat in development stage under chronic exposure of Pb and its effects on the memory development of the mice.

DESIGN:

A randomized controlled study employing experimental animals as subjects.

SETTING:

Cellbiology Key Laboratory of the Ministry of Health,China Medical University. MATERIALSThe study was conducted in the Laboratory of Biochemistry and Molecular Biology of China Medical University. Totally 72,5- 6 weeks old Kunming mice were selected.

METHODS:

Lead acetate of different concentration was used to feed female mice after copulation.Fetal mice contacted Pb through breast feeding and drinking water.Fetal mice were executed separately on 1st day(P1),8th day(P8),15th day(P15),22nd day(P22), and 30th day(P30) after birth for brain tissue harvesting.PCK activity in the brain tissue of the mice exposed to Pb was detected in vitro by[γ 32P] ATP.Budding mice were exposed to lead acetate of different concentration for the observation of the effects of Pb in difference concentration on the memory of the mice through memory behavioral training and test by passive avoidance response experiments.

RESULTS:

PKC activity detection indicated that PKC activity in brain of Pb exposed budding mice during initial growth stage was higher than normal,while it was lower than normal during advanced stage of growth.High concentration Pb had relative stronger inhibition on PKC activity.Memory behavioral training indicated that low concentration Pb would induce elevation of memory curve in the initial stage of the development in mice but reduction of memory curve in middle and long term.The increase of Pb concentration would reduce memory curve.

CONCLUSION:

Pb has inhibitive effects on the development of PKC activity in brain tissue of micethe higher the Pb concentration is, the more significant the inhibition is.Low concentration Pb seems to have stimulatory effects on memory in short period while long term exposure to Pb would induce memory inhibition.The inhibitive effect of high concentration Pb is more significant.Pb has certain correlation with PKC activity in brain tissues of budding mice and memory function.