Alkaline phosphatase activities following repeated suramin administration in some rat tissues in relation to their functions

Effect of chronic consumption of metabisulphite on the integrity of the rat kidney cellular system

The effect of chronic consumption of metabisulphite, a food preservative, on the integrity of the rat kidney cellular system was investigated. The levels of activities of some 'marker' enzymes were measured both before and after administration of between 1 and 15 doses of the chemical compound. Feeding of metabisulphite (5 mg/kg body wt.) to rats resulted in loss of alkaline phosphatase activities from the kidney beginning after the first dose. This was accompanied by a reduction of lactate dehydrogenase activity which was noticed as a secondary reaction, taking place after five daily doses. This was accompanied by an increase in alkaline phosphatase and a decrease in lactate dehydrogenase activities in the serum. An increased urinary excretion of protein and alkaline phosphatase activity was also obtained. Other enzymes assayed (acid phosphatase and glutamate dehydrogenase activities) were not significantly affected in the tissues and urine. All these results indicated that there is cellular damage to rat kidney as a result of chronic consumption of metabisulphite. They also indicate that the damage was primarily on the plasma membrane. The proximity of the soluble portion of the cytoplasm to the plasma membrane also makes it a secondary site of injury in the kidney cell.

Effect of repeated administration of berenil on urinary enzyme excretion with corresponding tissue pattern in rats

The effect of repeated administration of berenil, a trypanocide, on urinary excretion of some enzyme activities in rat and their corresponding levels in the kidney and serum was investigated. Daily administration of this drug to rats resulted in increased urinary volume, excretion of protein, alkaline phosphatase and lactate dehydrogenase activities. However, the level of acid phosphatase activity was not significantly increased while muramidase activity disappeared completely during the period of drug administration. In the kidney tissue, there was a significant loss of lactate dehydrogenase activity immediately after the first dose and this trend continued until the end of drug administration. In the same tissue, there was an increase in alkaline phosphatase activity while the lysosomal enzymes were not significantly affected. In the serum, except for the increase in alkaline phosphatase activity, all other enzymes were not significantly affected. All these results indicate that there is cellular damage to rat kidney as a result of repeated berenil administration, and that the plasma membrane and the soluble portion of the cytoplasm are the primary site of injury to the cells. They also suggest that urinary enzyme excretion could be useful in determining the site of cellular damage by chemical agents in kidneys.