Influence of pyridoxine (vitamin B6) on lead intoxication in rats.

Various studies have shown the important interrelationship between dietary nutrients and the toxicity of heavy metals. Antagonism or synergism may occur between lead (Pb) and nutritional factors at the sites of absorption or at the sites of effects. A diet low in protein, minerals and certain vitamins may not only enhance the circulating dose of Pb but may also reduce the general health status, particularly of children.1) Supplementation of vitamin B complexes2) has been shown to protect against toxic effects of Pb. However, the possible protective effects of various members of vitamin B complex on Pb intoxication have not been extensively studied. Supplementation of nicotinic acid3) and of thiamine4) has been shown to reduce Pb poisoning in experimental animals. In the present study, the influence of pyridoxine (vitamin B6) on Pb intoxication was investigated in rats. Twentyfour male albino rats (70±10 g) of ITRC colony housed in stainless steel cages maintained on standard pellet diet (MF: Hindustan Lever Ltd., India) and water ad-libitum were divided equally into 4 groups. The animals of all the groups were orally administered aqueous solutions (4 ml/kg body weight) of NaOOCCH3 (pH 6.0), pyridoxine. HCl (pH 4.0) (Analytical Reagent, Biogen Chemicals, India) and Pb (OOCCH3)2. 3H2O (pH 6.0) (Analytical grade, BDH, U.K.). The administration was performed through a gastric tube down the oesophagus daily for four weeks as follows. Group 1-8 mg/kg of NaOOCCH3 (Normal control). Group 2-10 mg/kg of pyridoxine. HCl. Group 3-10 mg/kg of Pb. Group 4-10 mg/kg of Pb followed by 10 mg/kg of pyridoxine. HCl.