Fig. 6. Effects of hyperglycemia on iNOS/eNOS distribution and NO production, and rescue by NO donor. The ability of NOC18 to restore normal vascular morphology of hyperglycemic treated conceptuses was evaluated by PECAM1 staining at 9.5 dpc: (A) hyperglycemia and (B) hyperglycemia plus NOC18. Morphometric analysis of images from PECAM1-stained yolk sacs showing vessel diameter distribution (C). Graphs of ERK2 normalized data for iNOS (D) and eNOS (E) protein expression in pooled 7.5, 8.5 and 9.5 dpc conceptuses. The broken lines represent the hyperglycemic condition, whereas the unbroken black lines represent the control (n=4, ^*P<0.05, ^**P<0.01). The data (mean±s.e.m.) is relative to the control 7.5 dpc levels. Above each graph is a representative western blot of iNOS and eNOS at 8.5 dpc. (F) Phase-contrast image of the endoderm of a 7.5 dpc conceptus showing the intact endodermal surface. (G) DAF-FM fluorescence of the corresponding area of a conceptus cultured in normoglycemic conditions. (H) DAFFM fluorescence of a similar area of a conceptus cultured in hyperglycemic conditions. (I) Representative western blot of the effect of a NO donor on NOS protein distribution of glucose treated conceptuses at 8.5 dpc and graph of ERK2 normalized averaged data for eNOS and iNOS protein expression (white columns represent eNOS and black columns represent iNOS; averages of two experiments). Nml, normoglycemic; HG, hyperglycaemic; HG + NOD, hyperglycemic + NOC-18.