THE EFFECT OF C5A AND U46619 ON THE ISOLATED, PERFUSED HUMAN PLACENTAL LOBULE - DEVELOPMENT OF A METHOD FOR THE ONLINE ESTIMATION OF TISSUE-FLUID ACCUMULATION

A method for the automatic and simultaneous determination of perfusion pressure and fluid accumulation in the isolated, perfused human place ntal lobule is described. We demonstrated that the inflammatory mediat or, C5a, a C5a agonist analogue peptide, and the thromboxane mimetic U 46619 caused increased fetal perfusion pressure and increased tissue w eight when administered via the fetal arterial circulation. Occlusion of the fetal venous effluent tubing caused significantly greater incre ases in tissue weight than the pharmacological agents. Detectable incr eases in tissue weight occurred within 47 +/- 3 sec (n = 21) following pressure increases caused by the pharmacological agents. In each case , the increase in tissue weight was accompanied by an increased permea bility of the materno-fetal barrier, shown by the transfer of Evans bl ue albumin from the fetal circulation to the maternal compartment.