Background: Atrial natriuretic peptide (ANP) is a 28 amino acid hormone secreted by atrial monocytes in response to local wall stretch. Recent studies have shown that glucocrticoides can express ANP genes and elevate its level. Ketokenazol is an antiadrenal drug used to reduceed glucocorticoides level, thus may result in reduction in ANP level. Thus, the present study was conducted to determine the physiologic effects of ANP on rats receiving ketokenazol.Materials and methods: Human atria were used for ANP. For ANP extraction preparation, tissue was boiled in specific solutions to inactivate intrinsic protease. Then cooling was carried out at 4 degrees centigrade and homogenization and centrifugation were occurred. PH was regulated using dialysis procedure.Results: Pulse, systolic and diastolic pressures were revealed to be higher in ketokenazol group. This may be due to reduction in vascular compliance. Injecting human atrial extract may decrease blood pressure by a slow slope.Conclusion: ANP may be safely used in atherosclerotic patients. Further clinical trials are suggested.

Background and Aim: Cataract is a major occular disease that causes blindness in many developing countries of the world. Experimental model of cataract is a first necessity to study the preventive factors of cataract progression. Several studies have shown that some glucocorticoides such as Dexamethasone (DEX) can induce cataract. The aim of this study was to form cataract in chick embryo.Materials and Methods: During three consequent stages, 120 fertile eggs were used in this study. In each stage 40 eggs in 4 groups were selected and put them into an incubator. Incubation was carried out at 37.5°C and 68% relative humidity. The day that the eggs were placed in the incubator was termed day 1. The first group received normal saline and the other three groups received 0.01, 0.02, and 0.04 micromole of dexamethasone (DEX) on the 14th, 15th, and 16th day of fertilization respectively. After 48 hours of DEX injection, lenses were removed and their opacity was classified into five stages by stereomicroscope (Olympus SZX) to determine the type of cataract. Microscopic study was done after hematoxylin-eosin staining. Data were collected and put in frequency tables and analyzed by Fisher and Chi Square tests in SPSS software and P<0.05 was taken as the significant level.Results: This study showed that use of 0.02 micromole of DEX on the 15th and 16th days of embryonic period can induce cataract in 95% of lenses. Also, use of 0.04 micromole of this drug on the 15th and 16th days of embryonic period can induce cataract in the 100% and 95% of chick lenses, respectively. Differences between cataract frequency of lenses in the experimental groups and control group were significant (P<0.0000), but there were no significant differences of cataract frequency between the experimental groups.Conclusion: Injection of 0.04 micromole of DEX on the 15th day of fertilization, as a choice dose and timecan induce cataract in chick embryo.