Effect of intraperitoneal zinc on the haematological profiles of C57/6J mice

Zinc is included in a number of medications and haematotoxic effects due to zinc excess have been reported. In this study, the haematological profiles (haematocrit, haemoglobin, total white blood cell count, differential white blood cell count and platelets) of mice treated with zinc were evaluated. Intraperitoneal zinc chloride was administered to C57/6J mice in varying dosages from 1.4-14 micrograms/g body weight, four times a week for a period of three weeks. Zinc chloride had no effect on the haematological profiles of these mice since the blood cell counts of treated mice were not significantly different from the controls (p < 0.05), with the exception that at half LD50 of zinc chloride (14 micrograms/g body weight) a reactive thrombocytosis resulted. (The platelet counts between the control and experimental group of mice were significantly different, exceeding 95% confidence limits; p = 0.016). We postulate that the specific effect on platelets was due to zinc being a potent inhibitor of phenol sulfotransferase (PST), an enzyme which is involved in many metabolic pathways. Platelets are a rich source of PST and the thrombocytosis observed was probably a compensatory mechanism to raise the levels of PST in the body.