S-nitrosoglutathione-containing hydrogel accelerates rat cutaneous wound repair.

BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization.

Contractile cells and fibrillin-1 distribution is disturbed in terminal villi of placentae from patients with preeclampsia and systemic lupus erythematosus.

Placentae from patients with preeclampsia (PE) and systemic lupus erythematosus (SLE) present many alterations that may impair materno-fetal exchange. We investigated the distribution of contractile cells and fibrillin-1 in terminal villi of term placentae from patients with PE or SLE and compared to control placentae. Stroma in terminal villi exhibited intense labelling for fibrillin-1. The fibrillin-1 villi surface fraction was greater in PE and SLE placentae than in controls (13+/-0.4%, 14+/-0.5%, 10+/-0.4%; p=0.0001). Immunohistochemistry for alpha-smooth muscle (SM) actin showed few contractile cells in control terminal villi stroma, localized around fetal capillaries and showed rare processes in vasculo-syncytial membrane. PE and SLE placentae exhibited an increase in the number of capillaries presenting alpha-SM actin adventitial positive cells. The presence of alpha-SM actin processes interposed in the vasculo-syncytial membrane was greater in SLE villi than in PE and controls. Ultrastructural observations confirmed in SLE and PE terminal villi the presence of these processes in vasculo-syncytial membrane and also showed a thickened trophoblastic basement membrane. The present study demonstrates that an important myofibroelastic system is present in term terminal villi, and that this system is actively remodelled in PE and SLE placentae.