The Effects of Feed Restriction during in Utero and Postnatal Development in Rats

Abstract

This study determined the effects of feed restriction (FR) during in utero and postnatal life on standard reproductive toxicity and developmental immunotoxicity end points. Groups of 26 time-mated CD rats were fed various amounts of Purina 5002 diet from gestation day 7 through lactation. Control rats were fed once per day in amounts based on historical control feed consumption data, while the amounts fed to the FR groups were reduced by 10% (10% FR), 30% (30% FR), or 50% (50% FR) relative to controls. Selected F1 weanlings were necropsied on postnatal day (PND) 22, assessed for immunotoxicity end points between PND 22 and 27 or PND 52 and 56, or maintained on FR through PND 70. Thereafter, half the remaining F1 rats in each group were fed ad lib (recovery subgroup), while the rest continued on FR. Both subgroups were necropsied at 21 weeks of age. In the 10% FR group, slight decreases in maternal body weight had no effect on F1 offspring body weights, but did decrease F1 liver weights. FR at the 30% level reduced maternal body weights by 10-20%, reduced F1 offspring body weights by as much as 21%, caused changes in numerous weanling organ weights, but did not affect reproductive or immune system function. Dams in the 50% FR group were 17-32% lighter than controls, resulting in F1 body weights that were 12-47% lower than controls. F1 estrous cycle length was increased, puberty was delayed by 6 days (males and females), and anogenital distance, epididymal sperm counts, and all organ weights were decreased in this group. Antibody responses were unaffected despite decreased spleen and thymus weights. Essentially all effects of feed restriction showed evidence of reversibility.

Pathological assessment of the nervous and male reproductive systems of rat offspring exposed maternally to acrylamide during the gestation and lactation periods - a preliminary study

“…Maternal body weights at weaning were decreased by 12% and 27% relative to the control dams in the 100 and 200 ppm groups, respectively. In a previous study of the effects of feed restriction during the gestation and lactation periods in rats, body weights of dams were decreased by 1-5%, 10-20% and 17-32% in the 10%, 30% and 50% food restriction groups, respectively (Carney et al, 2004), and the body weight curves were similar to those for our ACRtreated dams. Since reduced body weight gain concomitant with reduced food and water consumption was apparent here, particularly in the later stages of the experimental period, it can be considered that the advanced neurotoxicity due to ACR led to maternal malnutrition.…”

“…However, it has been reported that pup body weights were significantly decreased due to maternal malnutrition along with reduction of maternal body weight, food and water consumption in Wistar rats gavaged with ACR 25 mg/kg body weight/ day throughout lactation (Friedman et al, 1999). In addition, maternal food restriction during gestation and lactation suppresses pup body weight (Carney et al, 2004). Therefore, it is considered that the maternal malnutrition observed with ACR at ≥100 ppm could have greatly affected pup body weights in the present study.…”

Weight-of-the-evidence evaluation of 2,4-D potential for interactions with the estrogen, androgen and thyroid pathways and steroidogenesis

“…A previous feed restriction study with untreated rats showed weanling testes weights alter with decreased body weight (Carney et al 2004). In contrast, testes weights are conserved in the presence of similar/modest body weight decrements in adult male rats (Chapin et al 1993).…”

Diabesity: A Polygenic Model of Dietary-Induced Obesity from Ad Libitum Overfeeding of Sprague–Dawley Rats and Its Modulation by Moderate and Marked Dietary Restriction

“…As would be expected with endocrine disruption, ALoverfeeding had adverse effects on estrous cyclicity and onset of reproduction senescence in the SD females Merry et al, 1994;Keenan et al, 1995;McShane et al, 1996;Small et al, 2002;Pasquale et al, 2003;Rauser et al, 2003;Roy et al, 2003;Carney et al, 2004;Chiu et al, 1996). Since the stages of the polyestrous cycle in the rat can be classified by cell types present in vaginal lavage, and the cycle length is normally approximately 4 to 5 days, we monitored these parameters to determine the reproductive status of the unbred females on this study.…”