The effect of inmobilization stress on various pregnancy parameters and subsequent corporal development of the rat

Abstract

In this study we have examined the effects of inmmobilization stress in the rat during gestation. The duration of the pregnancy period, the number of pups, the sex ratio and the corporal developmente of the offspring from birth until waning was monitored. The rats are subjected to two hours of immobilization stress (from 9:00 to 11:00) at different stages of gestation: from day 1 to day 6 of pregnancy (Group 1), from day 17 to day 21 of pregnancy (Group 11) and during the entire pregnancy period (Group 111). No significant differences were obtained in the length of the gestation period, the size of the litter or the sex ratio. The stress applied seems to influence (p < 0,05) the prerinatal mortality percentage, the wight of the pups at birth and their later development until weaning. A lower weight was determined in the pups born in groups II and 111 and a higher weight in the pups born in group 1, all of this with regard to the control group and other experimental gruoups.