The Correlative Of The Levels Of Calcitonin Gene-related Peptide And Endothelin In The Patient With Type 2 Diabetic Nephropathy

BACKGROUND: Since this century, the incidence of diabetic mellitus is increased 3% every year in whole world. Diabetic nephropathy is one of the major chronic complications of diabetic mellitus, and 30-40% of it turn to end-stage renal failure which was main reason of death in patients with diabetic mellitus. So, it is a focal topic for scholar to prevention and cure diabetic nephropathy. The pathogenesis are still unknown up to now. At Present, the factors have been regarded as interaction of hemodynamics and no- hemodynamics. Recently, scholar paid close attention to the vasoactive peptide which influenced hemodynamics of renal. calcitonin gene-related peptide (CGRP) and endothelin (ET) were vasoactive peptides which discovered by scholar up to now, Endothelin was most powerful vasoconstrictors , and calcitonin gene-related peptide was most powerful non-adrenalegic and non-cholinergic vasoactive peptide to relax blood vessel. The balance of CGRP and ET kept renal hemodynamic stable. To detect changes of plasma calcitonin gene-related peptide and endothelin contents by RIA with type 2 diabetic mellitus according to different urinary albumin excretion rate of patients. To discuss the relationship of these two vasoactive peptide and development of DN, deeply explore the pathogenesis of diabetic nephropathy and provide some ideas for clinical prevention and cure diabetic nephropathy.OBJECTIVE: To investigate the significance of trend of plasma calcitonin gene-related peptide (CGRP) and endothelin(ET) contents in diabetic nephropathy, and primarily explore the relationship between calcitonin gene-related peptide, endothelin and pathogenesis of diabetic nephropathy.METHODS: This study included 25 healthy controls and 83 patients with type 2 diabetic mellitus or diabetic nephropathy. Type two diabetic patients were further divided into three subgroup according to their urinary albumin excretion rate (UAER), 28 cases with normal UAER, 29 cases with microalbuminuira and 26 cases with clinical proteinuria. Plasma calcitonin gene-related peptide and endothelin-1 contents were measured with radioimmunoassay (RIA). The blood lipid, sugar and urea nitrogen and serum creatinine contents were measured simultaneously.RESULT: The level of ET was significantly higher in type 2 diabetes and diabetic nephropathy than in controls (P<0.01), and elevation accompany by urinary albumin excretion rate increase. There was significant positive correlation between the level of ET and UAER in diabetic patients. (r=0.65, P<0.01). The level of CGRP was significantly lower in diabetic nephropathy than in controls (P<0.05 or P<0.01). There was significant negative correlation between the level of CGRP and UAER in diabetic patients. (r=—0.71, P<0.01). There was significant negative correlation between the level of CGRP and ET in diabetic patients. (r=-0.62, P<0.01).CONCLUSIONS: The disequilibrium of CGRP and ET in plasma might play an important role in the process of diabetic nephropathy. Therefore, keep balance of levels of CGRP and ET in plasma may be benefit for prevention and cure of diabetic nephropathy.