Lack of effect of protein deprivation-induced intrauterine growth retardation on behavior and corticosterone and growth hormone secretion in adult male rats: A long-term follow-up study

To further define the neuroendocrine consequences of intrauterine growth re tardation (IUGR), we have used a rat model of maternal protein restriction throughout pregnancy to examine the pattern of corticosterone and GH secret ion under basal conditions and in response to psychological stress in male offspring at 4, 9, and 18 months of age. The findings were correlated with studies of behavioral activity. Despite a consistent reduction in birth wei ght and failure of catch-up growth, there were no significant differences i n GH secretory profiles between IUGR and control rats at any age. We were u nable to demonstrate a difference in the number, amplitude, length, or area of corticosterone secretory pulses between control and IUGR animals; altho ugh again, there was a significant decrease with age. The mean peak plasma concentration of corticosterone in response to a noise stress also declined with age but was unaffected by IUGR. There were no consistent, statistical ly significant differences in behavioral responses between normal control a nd IUGR animals or between groups of animals at different ages. These resul ts do not, therefore, support the presence of major functional abnormalitie s in either GH or corticosterone secretory responses in adult male rats sub jected to IUGR.