EFFECT OF PRENATAL STRESS ON PLASMA-CORTICOSTERONE AND CATECHOLAMINESIN RESPONSE TO FOOTSHOCK IN RATS

The effect of prenatal stress was investigated on the sympathoadrenal response to novelty and footshock by measuring the time course of the changes in circulating corticosterone (COR) catecholamines and their m etabolites. Pregnant rats were subjected to noise and light stress, th ree times weekly on an unpredictable basis throughout gestation. When the male offspring of stressed rats (PS) and those of unstressed mothe rs (C) were 4.5-5 months of age, they were prepared with indwelling ca theters in the tail artery 24 h before the experiment. Resting levels of plasma COR, noradrenaline (NA), adrenaline (AD), dihydroxyphenylgly col (DHPG), dihydroxyphenylacetic acid (DOPAC), and dihydroxyphenylala nine (DOPA) were measured. Further blood samples were taken within 3 m in of their transfer to the shock box, 1-2, 5, 15, and 45 min after fo otshock. Plasma COR was significantly higher in PS than in C rats at r est, but those of adrenaline, NA, and their metabolites did not differ in the two groups. Transfer of the rats to the shock box increased pl asma COR,. NA, adrenaline, and dihydroxyphenylglycol in both groups, a nd dihydroxyphenylalanine and dihydroxyphenylacetic acid only in PS ra ts. All the catechols increased further 2-3 min after footshock, excep t dihydroxyphenylalanine in PS rats. Plasma NA and dihydroxyphenylglyc ol levels were significantly higher in PS than in C rats immediately a fter footshock, indicating a greater activation of the sympathetic ner vous system in PS rats. The findings demonstrate for the first time th at prenatal stress can induce long term changes in the sensitivity of the sympathoadrenal system to stress. (C) 1998 Elsevier Science Inc.