Role of endogenous oxytocin in cardiac ischemic preconditioning

Background: The aim of the present study is to assess the role of endogenous oxytocin (OT) in cardioprotective effects of ischemic preconditioning (IPC) in anesthetized rat. Materials and methods: Animals were divided into five groups: 1) ischemia-reperfusion (IR); (n= 6), hearts were subjected to 25 min regional ischemia and 60 min reperfusion, 2) OT; (n= 6), oxytocin was administered (0.03. μg/kg i.p) 10 min prior to ischemia, 3) IPC; (n= 7), IPC was induced via a 5 min regional ischemia followed by 5 min of reperfusion before IR, 4) IPC. +. ATO (Atosiban); (n= 6), atosiban (1.5. μg/kg i.p) was used as OT receptor selective antagonist in the beginning of IPC and 5) IR. +. ATO; (n= 6), atosiban was injected 10 min prior to ischemia-reperfusion. Results: In our experiment, Infarct size was decreased significantly in OT and IPC groups compared to IR (23 ± 1.5% and 19 ± 0.6% vs 45 ± 2.9% in IR group, P < 0.05). Administration of atosiban in IPC. +. ATO group increased infarct size to 39 ± 0.9% in comparison with OT and IPC groups (P<0.05). The use of OT and IPC prior to ischemia significantly declined ventricular arrhythmias severity in compared to IR group (1.2±0.4 and 1 ±0.5 respectively, vs 4±0.4 in IR group, P<0.05). Blockade of OT receptor by atosiban abolished the cardiopreconditioning effects of IPC. Conclusion: This study shows that, in part, the cardioprotective effects of IPC can be induced by endogenous OT. © 2010 Elsevier B.V

Priority Determination in Water Resources Allocation in Hirmand River Area

Supply and demand management of Hirmand water resources is one of the most important problems facing by policy makers and they will not be able to manage this sector properly without specifying the future prospects of the Hirmand Area. The main objective of the research is to determine the priority of future allocation of water resources in the Hirmand Area by using dynamic optimization models in different climatic conditions in agricultural, household, public and environmental sectors. The method of this research is based on the applied scientific method. The required statistics and information are obtained by the library method. In this research, the water demand functions in the agricultural, household, public and environmental sectors as well as the water supply function are achieved initially in different climatic conditions and then the general objective function for determining the allocation priority is estimated by using EVIEWS and GAMS soft wares. The results showed that in different conditions for agricultural sector, water demand is inversely related to water price, therefore under drought, wet and normal conditions, if the water price increases by one percent, the product will have a negative value decrease by 4.4%, 88% and 1.006% respectively. Moreover, since in this model the demand function for water is only a function of the price, the return to the scale is decreasing and Iso Quant Curve in the agricultural sector has a negative technical substitution rate in all aquatic conditions. In household demand, the results showed that with increase in water price, consumption decreases and rise of price is a necessary condition for reducing consumption, but is not sufficient. The average consumption based on the current trend is 12.42 M3 per month for each household. The reaction in the amount of demand change versus the change in the number of stormy days is positive and equal to 0.39. The results of the study for determination of water allocation indicate that if the next year is drought, priority of allocating for household sector will be (44%) - agriculture (41%) - Public (10%) and environmental (5%). In normal year, allocation priority will be (41%) household - (37%) agriculture - (14%) environmental and public sector (8%). While in rainy year, the allocation of priority has recorded for agriculture (43%) - domestic (39%) - environmental (15%) and public (7%). At the end some strategic policies based on research findings are suggested

Effect of graded doses of acetylsalicylic acid on sperm chromatin integrity and maturity of germinal epithelium in adult male mouse

Objective: To evaluate the effect of graded doses of acetylsalicylic acid (ASA) on sperm chromatin integrity and sex hormones in the adult male mouse. Methods: Forty-nine male adult mice were divided into seven groups. Control group received no drug, sham group received ASA solvent (dimethylsulfoxide 0.1%), groups 3 to 7 received different doses of 0.05, 0.10, 0.50, 1.00 and 5.00 mg ASA, daily for 14 d, respectively. On day 15, evaluations were made by sperm chromatin dispersion test for the study of DNA sperm integrity, radioimmunoassay for the study of testosterone and luteinizing hormone (LH) level and histopathology of testis for Jhonson’s scoring. Results: ASA in groups 0.50, 1.00 and 5.00 mg reduced big halo sperms. DNA fragmentation significantly increased just in 5 mg group. Serum level of testosterone in doses of 0.50, 1.00 and 5.00 mg groups reduced significantly (P<0.01) while LH level was not affected. Johnson’s score reduced in all ASA treated groups. Conclusions: Administration of ASA over the 14 days in dose of 5.00 mg increases sperm DNA fragmentation index and therefore reduces DNA integrity and in doses of 0.50, 1.00, 5.00 mg reduces serum testosterone level with no effect on LH. Generally, ASA has deleterious effects on the male reproductive indices even in low doses