[Variations in renal hemodynamics during acute renal insufficiency in anoxic neonates]

The purpose of this study is to verify if the increase of renal resistance, along with the consequent reduction of glomerular filtrate, and the activation of renina-angiotensin system, could be attributed to not only neonatal acute hypoxia but to other factors as well. These factors could provoke an increase in renal vascular resistance (R.V.R.), a reduction of renal blood flow (R.B.F.) and renal glomerular filtrate (R.G.F.) condition. These components are present in angiotensin as well as in endothelin (ET1), a potent peptide from vascular endothel with vasoconstricting action and whose secretion increases during hypoxia. The Authors have studied and compared two groups of newborns. The first group of newborns was affected by perinatal asphyxia or hypoxia of variable seriousness. It included 24 newborns with gestational age between 37 and 41 weeks and with a birth weight between 3.200 gms and 3.500 gms. The second, control group, was made of an identical number of newborns of the same gestational age with a weight adequate to the birth age. The dosage of the ET1 was evaluated on the plasma, using the RIA method. The diagnostic criteria for this evaluation included clinical and biohumoral evidence (tab. 1). Between the two groups, group 1 with anoxic syndrome showed the more intense increase of ET1. This increased is due to either an increase value of plasmatic creatinine that is present in normal situations or in physiopathologic role played by the ET1 in course of acute renal failure after asphyxia.