Objective To explore the regulatory role of calcium activated chloride channel (CaCC) in vascular structural remodeling in pathogenesis of pulmonary arterial hypertension (PAH) induced by high pulmonary blood flow.Method An abdominal aorta and inferior vena cava shunting operation was used to induce high pulmonary blood flow and establish a PAH rat model.Seventy-five SD rats were randomly divided into normal,sham,shunt,niflumic acid (NFA) 1 (0.2 mg/(kg · d)) and NFA 2 (0.4 mg/(kg · d)) groups.There were 15 rats in each group.Pulmonary artery pressure and vascular structural remodeling were measured,arteriole contraction ratio among these groups were compared using vascular tone analysis system,and the electrophysiology of pulmonary artery smooth muscle cell (PASMC) was recorded using patch clamp technology.Differences between multiple groups were compared through variance analysis and that between groups with q test.Result Compared with normal ((14.4 ± 1.3) mmHg,1 mmHg =0.133 kPa) and sham groups ((13.5 ± 2.3) mmHg),mean pulmonary artery pressure in shunt group ((27.4 ± 2.4) mmHg) increased significantly (P ＜ 0.05).Compared with shunt group,mean pulmonary artery pressure in NFA 1 group ((21.2 ± 2.0) mmHg) and NFA 2 group ((22.3 ± 2.0) mmHg) decreased significantly (P ＜ 0.05).Pulmonary vascular structural remodeling including pulmonary artery stenosis presented in shunt group.Compared with normal ((114.3 ± 1.2) ％) and sham ((115.5 ± 1.1) ％) groups,arteriole contraction ratio to 10-5 mol/L phenylephrine in shunt group ((132.6 ± 1.4) ％) increased significantly (P ＜ 0.05).Compared with shunt group,pulmonary vascular structural remodeling alleviated in NFA 1 and NFA 2 groups.Arteriole contraction ratio in NFA 1 group ((126.4 ± 1.3) ％) and NFA 2 group ((124.6 ± 1.0) ％) decreased significantly compared with shunt group (P ＜ 0.05).Patch clamp technique recorded typical CaCC currents.Compared with normal ((32.3 ±2.3) pA/pF) and sham groups ((35.3 ± 1.2) pA/pF),the CaCC current density of PASMC in shunt group ((51.3 ± 2.7) pA/pF) increased significantly (P ＜ 0.05).Compared with shunt group,the CaCC current density of PASMC in NFA 1 group ((40.2 ± 1.5) pA/pF) and NFA 2 group ((42.7 ± 2.2) pA/pF) decreased significantly (P ＜ 0.05).Conclusion CaCC is involved in pulmonary arterial hypertension induced by high pulmonary blood flow through regulating membrane potential.NFA attenuate pulmonary vascular structural remodeling and pulmonarv pressure through decreasing CaCC current density of PASMC membrane.

Objective To evaluate the effect of living skin equivalents (LSE) constructed of mixed autologous and allogeneic skin cells and human amnion which served as a matrix on repairing scar contracture of the hand in a patient with recessive dystrophic epidermolysis bullosa (RDEB).Methods Skin tissues were obtained from a patient with RDEB and her mother,and epidermal keratinocytes and dermal fibroblasts were isolated from these tissues and cultured in vitro separately.Human amnion was obtained from the placenta of an unrelated healthy parturient undergoing cesarean delivery,and served as a matrix of the LSE.The autologous and allogeneic fibroblasts were mixed and seeded on the stromal side of the amnion,and then the autologous and allogeneic keratinocytes were mixed and seeded on the epithelial side of the amnion,so as to construct the human amnion-LSE (AM-LSE).Histological examination was performed to observe the structure of the skin tissues obtained from the patient and her mother,and immunofluorescence staining was conducted to detect the expression of type Ⅶ collagen in the skin tissues of the patient and her mother and in the AM-LSE.The AM-LSE was grafted on the skin defects of the patient after release of scar contracture of the hand.After grafting,the survival status of the AM-LSE graft and repairing effect on the wounds were evaluated.Results The constructed AM-LSE consisted of dermis,multilayered and fully differentiated epidermis and well-developed basement membrane.Immunofluorescence examination revealed that type Ⅶ collagen was linearly distributed along the basement membrane.Half a year after grafting,the AM-LSE survived well,and no obvious rejection reaction was observed.No blisters or ulcers occurred at the recipient sites,and the scar contracture was mild.The grafted area showed normal skin color with soft texture.The patient could grab and hold things,which had met self-care requirements of daily living.Conclusions The AM-LSE constructed of mixed autologous and allogeneic skin cells have good histological structures,and can be grafted on the wounds after resection of the scars in a RDEB patient.After grafting,no obvious rejection reaction was observed,and the skin was not liable to develop blisters,ulcers or scar contracture due to friction.