ARI Volume 2 Number 1.pdf - Zoo-unn.org

OLUAH, Ndubuisi Stanley et al. 232Gammalin 20.The fish were exposed to thesesublethal concentrations of the pesticide in arenewal bioassay system in which the water andthe pesticides were changed every two days tomaintain the toxicant concentrations. The fishwere fed 30 % crude protein diet at 3% bodyweight daily at 8.00 h. The Experiment lasted for18 days and the lactate dehydrogenase activitywas assayed every six days.Tissue Collection and Enzyme Assay: Theblood samples were collected by both the cardiacpuncture method and the severance of the caudalpeduncle using the disposable hypodermic syringe(Oluah, 1999). The liver was excised and washedin distilled water to remove traces of blood. Theliver samples were macerated and homogenized asdescribed by Devi et al. (1993). The liver washomogenized in ice-cold 0.25 M sucrose. The liverhomogenate was centrifuged at 5000 rpm for 15minutes at 4 o C.The blood was similarly centrifugedfor 15 minutes at 1000 rpm to obtain the serum.The liver supernatant and serum were used for thelactate dehydrogenase (LDH) assay. The lactatedehydrogenase activity was calorimetricallydetermined at 445 nm using Sigma protocolnumber 500 (Sigma Chemical Company, St Louis,MO). The data from the replicate experimentswere averaged and the mean (± SD) presented.The analysis of variance (ANOVA) was used toanalyze the data for statistical significance (P