A potential role for N-cadherin in mediating endothelial cell-smooth muscle cell interactions in the rat vasculature.

BACKGROUND: The cadherins are a family of calcium-dependent cell adhesion molecules that play a critical role in morphogenetic cell interactions in the embryo. N-cadherin has been identified in neural and non-neural tissues, including developing muscle; however, there are few reports of N-cadherin expression in adult mammals. We attempted to identify N-cadherin in the rat vasculature and to ask whether it has a role in mediating vascular cell interactions. EXPERIMENTAL DESIGN: Vascular tissues were isolated from Fischer rats and analyzed immunohistochemically and by Western blotting using pan-cadherin and N-cadherin antibodies. Anti-N-cadherin antibodies were used in an in vitro cell adhesion assay to determine if N-cadherin mediates interactions between smooth muscle cells (SMC) and endothelial cells (EC). RESULTS: Western blot analysis of vascular tissues reveals a 135 kilodalton (kd) band that is recognized by anti-N-cadherin antibodies. N-cadherin localizes in the rat aorta to the endothelium and to the smooth muscle cell layer beneath the internal elastic membrane. A cell adhesion assay demonstrates that rat SMCs and ECs adhere to each other in a Ca(2+)-dependent manner, and an anti-N-cadherin antibody inhibits approximately 25% of this adhesion. CONCLUSIONS: Our data indicate that N-cadherin is expressed in large vessels of the rat and is capable of mediating EC-SMC adhesion in vitro. It is noteworthy that N-cadherin localizes to a population of SMCs in the rat aorta adjacent to ECs suggesting that N-cadherin may mediate EC-SMC interactions in vivo.

Placental and fetal development in straightbred and reciprocal crosses of Yorkshire and Ossabaw swine.

Placental and fetal development were compared in 7 Yorkshire (Y) and 12 feral, Ossabaw (F) gilts mated to Y and F boars to produce straightbred and reciprocal cross litters (YY, YF, FY and FF, sire listed first). Gilts were slaughtered at d 75 +/- 2 of gestation. Ovulatory rate and litter size were higher in Y than in F gilts; however, rates of embyonal survival were similar in all groups. Groups differed in fetal body weight, metabolic body weight, crown-to-rump length, placental weight, metabolic placental weight and placental surface area, respectively. The YY group had highest values and the FF group smallest values for all variables except placental surface area. Pearson product-moment correlation coefficients of placental development with fetal length and weight across breeding groups were significant (e.g., placental surface area: fetal length, r = .67; placental surface area: fetal metabolic body weight, r = .76). It is concluded that the relationship between placental and fetal development observed in domestic swine is present in feral swine and crosses between domestic and feral swine at this gestational stage. These developmental measures are significantly influenced by fetal genotype and uterine environment but also by the breed of sire.