J. CATALA, M. DAUMAS, *M. OUARDANI et *J. LEUNG TACK. Institut de Physiologic, Rue Magendie,Toulouse 31400, *INSERM 388, htstitut L. Bugnard, CHU Rangueil, Toulouse 31054, France. Non-insulino-dependent diabetes (NIDD) in rabbit following pancreatic duct ligature was characterized by chronic glucose intolerance and hypo-c-peptidemia. This model presents a transitory period (25 to 35 th day postligature) of hyperglycemia and hypoinsulinemia correlated with renal hyperfiltration and glycosuria. In this study we investigated the abnormalities of glomerular mesangial cell contraction recently observed in STZ treated IDD adult rats. These experiments were performed on mesangial cells obtained from glomeruli of rabbits at 30th day postligature.Two aspects were investigated : morphological characterization of cytoskeletal protein (actin) in relation with functional contractile activity, in response to a vasoactive peptide, bradykinin (BK) and a depolarizing factor (KC1). Mesangial contraction was mesured by using an AES-image analyser. A decrease of contractile activity was observed in diabetic cells both in response to KC1 and BK, thus suggesting an alteration of Ca2+ channels associated to a dysfunction of the contractile system. In addition, the lowest contraction induced by BK suggested some abnormalities of intracellular mechanisms involving BK receptor activation. The contractile alterations seemed to be, for a part, responsible of the transitory renal hyperfiltration observed in this noninsulino-dependent diabetes model and was similar to STZ treated IDD model. 30 Development of cytotoxicity tests applied to human haematopoietic progenitor cultures.
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