Fetomaternal transfer of glucose in human placenta: Relation to fetal blood pressure

Abstract

Apparently carbohydrates are transported across the placenta by a carrier system. The influence of both altered pressure and flow in the fetal vascular system and of insulin in the maternal circulation upon the maternofetal transport of glucose were studied. Segments of five placentas were studied by an open dual perfusion system. 1.) Using a maternofetal glucose gradient (range 266 - 425 mg/100 ml), augmented fetal flow by increased blood pressure did not alter the relative glucose transfer rate (mean 0.0894 mg/min./g placenta, SEM ± 0.03 for a glucose gradient of 100 mg/100 ml) from maternal to fetal system. 2.) Without any glucose gradient, an influence of fetal pressure variation on the transfer of glucose could not be demonstrated. 3.) Insulin infusion to maternal circulation does not change the glucose transfer. - The assumed carrier complex for the facilitated diffusion of glucose will not be altered by blood pressure in physiological range and by the maternal insulin concentration.