| Objective: At the present time the study of diabetes encephalopathy focus on brain blood flow and metabolism. But there are seldom research on the influence of diabetes to brain tissue and induce chronic diabetes encephalopathy. The technique of molecular and biology makes it possible that we can explore the mechanism of chronic diabetes encephalopathy through testing the distribution of neurotransmitter in the brain. In this research we construct streptozotocin-induced diabetic rats model and use in situ hybridication and histochemistry technology to study the changes of somatostatin mRNA in the CNS. To find the relationship between diabetes and somatostatin, we study the mechanism of chronic diabetes encephalopathy. This can provide theory basis and curative ways in clinical practice. Materials and Methods: 1. Animal groups 20 SD rats that weighing 150-200g were divided into two groups at random. Group A is normal control group while Group B is diabetes model group. 2. Diabetic rats models manufacture, test of blood sugar and urine sugar In group B, rats were injected streptozotocin intraperitoneally with 60mg/kg after R322 .7. Fasting for ten hours. 48hours later, the blood sugar and urine sugar of rats were tested. We found that their blood sugar was over 16.65 mrnolIL (300mg/dl) and urine sugar was over ++ demostrating the animal acute diabetes model was succeeded. And then the blood sugar and urine sugar were tested every two weeks and every week respectively. 3. In situ hybridication study on SST mRNA in rats?brain 1) Freeze section: Four weeks after constructed animal model all rats both groupA and group B were anesthetized with 30mg/kg sodium pentobarbital intraperitoneally. Poured 300m1 saline into aorta first and then poured 4% citromint about 20-30 mm. Taking out of brain through opening the rat抯 cranial cavity. The brain was in 4% citromint for 6-8 h, then put it in 20% sugar solutions till the tissue sank. We could make serial freeze sections (about 30-4Oum) of brain then put the sections in 4% citromint for 4h. 2) Sections pretreatment 3) Hybridication, washing and staining NBT and BCIP staining 4) Paste and seal sections 4. Positive contrast (distribution of SST in cortex of frontal lobe) and Negative contrast (SST mRNA probe being taken place with PBS buffer) 5. Image analysis and statistics Got one section from every rat and selected the hippocampi and dentate gyrus area to analysis SST mRNA positive neuron cell in Static [MG 2.0 Image Analysis R322 System . The number , light density and average area of positive cells were observed and measured. All data was statistical in SPSS 8.0. Result I. Weigh, blood sugar and urine sugar: the data of weigh, blood sugar and urine sugar indicates no distinct differences between group A and B before model constructed. At four weeks after constructed animal model the weigh was 199.l眑S.6g , blood sugar was 427?8.5 mg/dl and urine sugar was (++) -~ (+++) in diabetes model group while the normal control group was 266.5 ?30.3 g, 87.2 ?II .3 mg/dl and (--). There were...
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