Effects Of Nutrients On Islet β Cell Mass And Islet Function In STZ Diabetic Rat

Virus infection, autoimmune reaction and environment toxin can lead to reduction of isletβcells mass and absolute deficiency of insulin, which is the pathologic foundation of typeⅠdiabetes mellitus (IDDM). It is the key point of cure to recover isletβ-cell mass and islet function in diabetic individual.In recent years, regeneration and amplification of βcell were found in normal pregnant rats, obese rats, diabetic rats induced by STZ, adult rats of 95% pancreastectomy and STZ diabetic mice receiving islet transplantation in kidney capsule. It was found that some nutrients such as amino acids, unsaturated fatty acids and vitamins can not only induce and promote regeneration and amplification ofβcell, but also resist against the toxic effect of high glucose and high lipid on growth and function ofβcell in vivo and in vitro.Relevant researches suggest that nutrients are important in maintaining stability of βcell function andβcell mass in normal organism. It was reported that the balance of nutrients changed abnormally in diabetes mellitus, which may be one of the main reasons thatβ-cell mass and islet function can't return in diabetes mellitus. It may be also a fundamental reason that single nutrients can't ultimately prevent against high blood glucose in experimental diabetic animal.We hypothesize that it is essential for various nutrients at a range of the certain concentration ratio to maintains dynamic balance of βcell mass and islet function in physiological condition. In diabetes mellitus, the concentration ratio of the nutrients disorders abnormally. Therefore, it is possible for regulating the concentration ratio of the nutrients to normal ratio range to recoverβcell mass and islet function in diabetes mellitus.In diabetic research, comprehending about the relation ofβcell mass to glucose, insulin and C peptide levels, especially changes in these parameters, could be of great important for cognizing diabetic degree and treatment effect. Therefore, The study explore the relation of glucose, insulin and C peptide levels toβcell mass and the effect of some nutrients onβcell mass and islet function in diabetic rat induced by STZ.Part 1. The relationship between isletβcell mass and glucose, insulin, C peptide in diabetic rat induced by STZObjective The study would like explore the relation of isletβcell mass reduction to developing degree in diabetic rat induced by STZ through analyzingβcell mass and the levels of glucose, insulin and C peptide. Method 50 SD rats, male 210-230g. 6 rats were selected at random as normal control. The rest were given 1% STZ sodium citrate dispensed freshly (0.1M, pH4.5,) by abdominal injection after 12 hr free-feed. the three dose of STZ used in three experimental group were 43 mg/kg,50 mg/kg, 57 mg/kg respectively, which were called group A,B and C. Two weeks later, blood was collected from orbit venous plexus to examine fasting glucose, insulin and C peptide. The rat that its fasting glucose was more than 7.2 mmol/L glucose would be regarded as diabetic rat.Then, rat pancreases were got by pentobarbital narcosis. and filleted, stained by immunohistochemistry and counted βcell mass by point conuting morphonetry. Result The change in glucose, insulin and C peptide All of the 43, 50, 57 mg/kg STZ could increase glucose levels and decrease the concentrations of insulin and C peptide. There was significant difference between each group treated by STZ and normal rat group, p < 0.05, 43 mg/kg STZ caused minimal change in the levels of glucose, insulin and C peptide; 50 mg/kg and 57 mg/kg STZ bring about significant alteration in these parameters.The Change in isletβcell massCompared to that of normal rat, 43 mg/kg STZ reduced rat isletβcell mass with 52.61% mortality, 50mg/kg and 57 mg/kg STZ caused great reduction, which was 77.4 %和 80.26 %, and no significant difference between this two dose groups was found. However, there was significant difference in the reduction of βcell mass between norm...