Is use of a cellulose-diluted diet a viable alternative to pair-feeding?

Abstract

Pair-feeding (PF) has been traditionally used as a nutrition control for drugs that reduce food intake during pregnancy. This method of dietary restriction has been shown to induce alterations in the behavior and physiology of the dams, with some consequent effects on their offspring. Dams treated with cocaine typically exhibit a transient reduction in food intake lasting 3–5 days. A novel nutritional control, using a cellulose-diluted diet, was developed to control for this transient anorexia without requiring explicit food restriction. Daily body weights and food and water intake were measured in Sprague-Dawley dams that received subcutaneous injections of 40 mg/kg/3 cc of cocaine hydrochloride (C40) daily on gestational day 8–20, pair-fed (PF) dams that were injected with saline, and nontreated control dams (LC). In addition, another group of dams were placed on a powdered chow diet diluted with cellulose (40% by weight) and were injected with saline from gestational day 8–20 (NC). Both the food intake and body weight gain of NC and PF dams closely matched that of C40 dams. NC dams were more similar in water intake to cocaine-treated dams than PF dams. However, offspring of NC dams exhibited a significant reduction in pup body weight on postnatal day 1 when compared to PF, LC, and C40 offspring, a finding which limits the usefulness of this novel nutritional control procedure. Thus, pair-feeding still appears to be the best available method for controlling the nutritional consequences of developmental toxicants.