Lectin histochemistry in the human placenta of pregnancies complicated by intrauterine growth retardation based on absent or reversed diastolic flow.

The oligosaccharide distribution of the glycoconjugates was investigated in placental tissue of pregnancies complicated by intrauterine growth retardation (IUGR) with absent or reversed flow in the umbilical artery (ARED), between the 29 and the 37 weeks of pregnancy. Placentae of a gestational age-matched group of normally grown pregnancies was also selected as control group. For this purpose a battery of seven HRP-conjugated lectins was used (DBA, SBA, PNA, ConA, WGA, LTA and UEA I). Our data showed that alpha-D-mannose (ConA), N-acetyl-D-glucosamine (WGA), beta-N-acetyl-D-galactosamine (SBA), alpha-L-fucose (LTA and UEA I) were present in less amount or were not present in the trophoblast and/or in the endothelial cells of the pathological group compared to the control one. The trophoblast basement membrane and/or basal plasma membrane of the pathological placentae were characterized by the presence of alpha-D-mannose (ConA), N-acetyl-D-glucosamine (WGA), sialic acid and D-galactose-(beta1-->3)-N-acetyl-D-galactosamine (neuraminidase-PNA), only in some tracts, in all the weeks of gestation. In the control placentae these sugar residues were present in the whole basement membrane and/or basal plasma membrane from 31 or 35 weeks. The Hofbauer cells of the pathological placental tissue showed a less amount or lack of alpha-D-mannose (ConA), beta-N-acetyl-D-galactosamine (SBA) and alpha-L-fucose (UEA I) compared to the control ones. These results suggest that a less amount or lack of some sugar residues may contribute to restricted placenta growth and development and thus reduced efficiency in maternal-fetal exchanges of gases and metabolites.