RESEARCH

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AUTHORS	Chetty CS. Rajanna S. Hall E. Yallapragada PR. Rajanna B.
INSTITUTION	Department of Biology, Savannah State College, GA, USA
TITLE	In vitro and in vivo effects of lead, methyl mercury and mercury on inositol 1,4,5-trisphosphate and 1,3,4,5-tetrakisphospate receptor bindings in rat brain.
SOURCE	Toxicology Letters. 87(1):11-7, 1996 Sep.
COUNTRY OF PUBLICATION	Netherlands
ABSTRACT	In vitro and in vivo effects of mercury (Hg), methyl mercury (MM) and lead (Pb) on [3H]inositol 1,4,5,-trisphosphate (IP3) and [3H]inositol 1,3,4,5-tetrakisphospate (IP4) receptor binding in the Sprague-Dawley rat brain cerebellar membranes were studied. In vitro studies indicate that binding of [3H]IP3 and [3H]IP4 to cerebellar membranes was inhibited by Hg while they were stimulated by MM or Pb in a concentration-dependent manner. MM was more potent (EC50 3.4 microM) than Pb (EC50 18.2 microM) was more potent than MM (IC50 133 microM) in stimulating the [3H]IP4 receptor binding. When the rats were treated (i.p) with Hg (5 mg/kg body wt.) alterations in [3H)IP3 receptor binding were observed in cerebellum and cerebral cortex. But the above treatment of Pb or MM for 3 or 24 h to rats resulted in an increase of [3H]IP4 receptor binding in the membranes of cerebral cortex. However, the rats treated with Hg (1 mg/kg body wt./day) for 7 days. The cerebellum and cerebral cortex of rats with the above treatment of MM or Pb for 7 days exhibited an increase i [3H]IP4 receptor binding. These in vitro and in vivo data suggest that alterations in inositol polyphosphate receptor binding by metals could result in alterations in intracellular calcium levels which may influence neuronal activity.
PUBLICATION TYPE	Journal Article
LANGUAGE	English