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Background and Objective: The role of ion channels and particularly cationic channels in the pathogenesis of various diseases are being considered carefully. The diabetes mellitus is a common disease which is initiated by ion channel disturbances. This study was done to determine the characteristics of hepatocyte rough endoplasmic reticulum single cationic channel in Streptozocin- induced diabetic rats.

Materials and Methods: This experimental study was done on 10 male adult Wistar rats and animals were randomly allocaied into diabetic and control groups. Diabetes induced by STZ (65 mg/kg/bw) intraperitounally. Rough endoplasmic reticulum vesicles were extracted following rat liver excision, homogenization and ultracentrifuging. The bilayer membrane formation was prepared by painting phosphatidylcholine on 250µM aperture in between Cis and Trans sides. The RER vesicles incorporation was performed through gentle and delicate touch of membrane using a dentistry needle. The Pclamp9 software was used for ion channel activity characteristic analysis.

Results: The cationic channel current amplitude did not change significantly in voltages more than +3o mV but their open probability (Po) decreased in diabetic group (P<0.05). More severe changes in channel activity were seen in potentials less than the reverse potential. In addition to significant increase of channel Po (P<0.05), also, the channel unitary currents were significantly decreased (P<0.05). The mean current amplitude and channel open probability in voltage +40 mV were 17±2.14 pA and 0.68±0.01 in control group respectively, whereas, the values of these parameters reached to 18.5±2.5 and 0.26±0.03, respectively. In voltage -10 mV, the values of mean current amplitude and Po were -22.3±2.14 pA and <0.1 in control group, respectively but the values changed to -13.1±0.08 and 0.62±0.03 in diabetic group.

Conclusion: It seems that RER cationic channel is involved in metabolic changes which cause by diabetes mellitus and this disease can cause probably a channel gating kinetic and behavior change by inducing metabolic stresses.

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Background and Objective: Atorvastatin is a member of the statin family with lipophilic character and anti-hyperlipidemic effect. There is many evidence that atorvastatin has protective effect on cognitive function. This study was done to evaluate the effect of atorvastatin on spatial memory in rats following a high-fat diet.
Methods: This experimental study was performed on 35 male Wistar male rats. Animals were randomly allocated into 5 groups including control, control plus atorvastatin and sham (received high-fat diet for 4 weeks) and high-fat diet plus atorvastatin (10 and 50 mg/kg, for 4 weeks). Learning and spatial memory were measured using Morris water maze for a 6-day period including 5 days training and the last day, test day (probe day).
Results: High-fat diet reduced learning and poor memory performance during training and probe compared to the control group, and also on the probe day, the high-fat group spent less time in the target quarter (P<0.05). Administration of atorvastatin after a high-fat diet improvement spatial memory in compared to high-fat group (P<0.05).
Conclusion: Short-term treatment (4 weeks) with atorvastatin in high-fat dietary rats can improve spatial memory.