Abstract
Plasma arginine vasopressin (pAVP) release was measured before and during fetal hemorrhage (H) and 3 hours after fetal blood replacement (T) in 11 chronic fetal lamb preparations (103-138 days gestation). During H there were significant decreases (p<0.05) in fetal hematocrit (34.7±2.5 to 27±1.5%), arterial blood pressure (BP)(58.1±2.5 to 52.2±2.5 mmHg) and fetal pH (7.38±0.01 to 7.35±0.01), but no changes were seen in arterial blood gases (PCO2 − PO2), plasma electrolytes (Na+, K+, C1−) nor osmolality. After T all values returned to baseline levels. Fetal pAVP was measured at various levels of H until ∼30% of the total feto-placental blood volume (T-FPV) was removed. Fetal pAVP increased significantly (p<0.01) in all fetuses from mean basal values of 0.73±0.21 to mean peak values of 34.9±10.04 μU/ml. pAVP was returned to baseline values (1.77±0.67 μU/ml) 3 hours after T. No change in maternal pAVP was seen during H. When fetal pAVP was plotted against the percent of T-FPV removed, the correlation coefficient was 0.65; however, when the log of fetal pAVP was plotted against the percent of T-FPV removed, a correlation coefficient of 0.82 was observed. A multiple regression analysis showed that the decrease in fetal BP was not the primary factor explaining the increase in pAVP during T-FPV depletion. These data show that H is a potent stimulus for fetall pAVP release and suggest that this release is an exponential function of the degree to which T-FPV is depleted.
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Robillard, J., Weitzman, R. & Smith, F. 207 THE DYNAMICS OF VASOPRESSIN RESPONSE TO BLOOD VOLUME DEPLETION IN THE LAMB FETUS. Pediatr Res 12 (Suppl 4), 398 (1978). https://doi.org/10.1203/00006450-197804001-00212
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DOI: https://doi.org/10.1203/00006450-197804001-00212