ABSTRACT
<p><b>AIM</b>To investigate the mechanism through which insulin affect the learning and memory abilities of the Alzheimer's disease-like rats.</p><p><b>METHODS</b>Okadaic acid (OA) was injected into the CA1 region of the rat hippocampus and the insulin was injected into the lateral cerebral ventricle of the rats. The learning and memory abilities of the rats were assessed through Morriswater maze behavioral test, and the expressions of nicotinic acetylcholine receptors and GFAP were observed by Westem blotting and immunohistochemistry, respectively.</p><p><b>RESULTS</b>Compared with the control rats, the abilities of learning and memory were lowered significantly (P < 0.01) and the expressions of the nicotinic acetylcholine receptors were decreased and the GFAP positive astrocytes were increased greatly in the model rats (P < 0.05). In the rats injected with insulin, it was found that their learning and memory abilities were improved significantly (P < 0.01) and that the expression of the nicotinic acetylcholine receptors were increased and GFAP positive astrocytes were decreased obviously (P < 0.05), as compared with the model rats.</p><p><b>CONCLUSION</b>Insulin is able to enhance the learning and memory abilities of the Alzheimer's disease-like rats, possibly by improving the function of the acetylcholine system and decreasing the astrocytes proliferation in the brain.</p>
Subject(s)
Animals , Male , Rats , Alzheimer Disease , Glial Fibrillary Acidic Protein , Metabolism , Insulin , Pharmacology , Learning , Memory , Random Allocation , Rats, Wistar , Receptors, Nicotinic , MetabolismABSTRACT
Objective To observe the effects of Ang-Ⅱ on expressions of c-fos mRNA and pro-α1［Ⅰ］mRNA in fibroblasts (FBC) of rat embryo in the course of collagen synthesis.Methods The change of free Ca2+(［Ca2+］i) was tested in fluorometry and the expressions of c-fos mRNA and pro-α1［Ⅰ］mRNA were tested by RT-PCR method in incubated FBC.Results The level of［Ca2+］i in FBC and the expressions of c-fos mRNA and pro-α1［Ⅰ］mRNA were enhanced with the increase of Ang-Ⅱ concentration(10-8～10-5and 10-7～10-6mol/L).Conclusions The expressions of c-fos mRNA and pro-α1［Ⅰ］mRNA were induced by Ang-Ⅱ activating signal system in FBC.