UTTAR PRADESH JOURNAL OF ZOOLOGY

The present work was carried out to study the clinical signs, mortality and hematological alterations induced by administration of nanonickel in Wistar rats at NOAEL dose for a period of 90 days.  A total of 35 rats of six weeks of age, of both sexes, were randomly divided into two groups. Group I was kept as control and comprising of 20 rats. Group II was comprising of 15 rats and were orally administered nanonickel mixed in distilled water orally at NOAEL dose rate of 5 mg/kg body weight/day from 0 day of experiment till 90 days post treatment (DPT). Animals were observed twice daily for the presence of any untoward clinical signs and mortality throughout the period of experimentation. Blood was collected from 5 rats from each group at 0 (5 rats from control group only at this interval), 30^th, 60^th and 90^th DPT to study the hematological parameters.  Body weight of both the groups of rats was also recorded at the above said intervals. Animals of the both the groups showed no clinical signs and mortality throughout the experimentation. Group I rats showed no significant variation in body weight and hematological values. A significant time dependent decrease in body weight was recorded in group II rats. Hematological studies revealed a non-significant decrease in hemoglobin (Hb) and significant decrease in packed cell volume (PCV) values at 60^th and 90^th DPT, in treated rats as compared to control rats while there was a significant decrease in total erythrocyte count (TEC) at 30^th and 90^th DPT in treated rats. There is significant decrease in mean corpuscular volume (MCV) at 60^th DPT and significant increase in mean corpuscular hemoglobin (MCH) also there was increase in mean corpuscular hemoglobin concentration (MCHC) in treated rats as compared to control rats at all the DPT. There was a decrease in total leucocyte count at all DPT in treated rats as compared to control rats. In differential leucocyte count, a significant decrease in lymphocyte count and neutrophil count at 30^th and 60^th DPT. There was a significant increase in eosinophil at 30^th and 90^th DPT and a significant increase in monocyte count at 30^th DPT. There was significant decrease in absolute neutrophil count at 90^th DPT in treated rats as compared to control rats while there was significant decrease in absolute lymphocyte count at 30^th DPT. It can be concluded from the present study that nanonickel have adverse effects on body weight and hematological parameters of Wistar rats at NOAEL dose.