Statistical Approach to Evaluating Effect of Physical and Chemical Factors on Fecal Excretion of Chlorophenothane

Abstract

A study using 14C-labeled chlorophenothane was statistically designed to evaluate the effect of five treatments (cold, fasting, levarterenol bitartrate, prediphenylhydantoin, and post- diphenylhydantoin) upon the fecal elimination of the pesticide from rats. To 24-hr.-fasted rats, 7 μc. of 14C-chlorophcnothane was administered intraperitoneally. The pesticide was allowed to distribute into the tissues of the animals for 5 days prior to initiation of the treatments which were continued for 3 days. The cold group was kept at 2-4°. The fasted rats were deprived of food but had water ad libitum. Levarterenol bitartrate and diphenylhydantoin were administered twice a day at 1.0 and 75.0 mg./kg. body weight, respectively. Diphenylhydantoin was administered before chlorophenothane (prediphenylhydantoin) to one group of rats and after administration of the pesticide (postdiphenylhydantoin) to a second group. The 14C-activity in the feces was measured by liquid scintillation. Thirty-six rats were assigned in a randomized complete block design of three replicates with two rats per treatment, five treatments, and a control per replicate. Homogeneity of variance tests indicated that the variances between rats were homogeneous. Two- way analysis of variance tests showed that replicates could be pooled and the data reanalyzed as if a completely randomized design were run. Hence, a one-way analysis of variance and the Newman-Keuls sequential range tests were performed. The latter tested for significant differences between all pairs of treatments. The statistical design allowed for minimum expenditure of animals and radioisotope and provided reliable data. Cold treatment was the only treatment that increased the fecal elimination of chlorophenothane. Prcadministration of diphenylhydantoin may have stimulated hepatic enzymes to alter deposition and increase apparent elimination of chlorophenothane.