Tehran University Medical Journal

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Background: Nitric oxide (NO) is produced in different body organs in mammals and numerous physiological and pathological properties are attributed to this small molecule. The precursor of this substance in the body, L-arginine, is synthesized by the enzyme nitric oxide synthase (NOS), and it is catalyzed, and is inhibited by a substance called L-NG-nitroarginine methyl ester (L-NAME). In this study we investigated the qualitative and quantitative effects of nitric oxide on cerebellar histopathology in vivo environment via increasing and decreasing its production.
Methods: Forty Wister rats, weighing 200- 250 gr with a mean age of 8 weeks, were divided into 5 groups after making sure the rats were pregnant. Except the control group, the other pregnant groups, respectively received: 2 ml/kg normal saline, 200 mg/kg L-arginine, 20 mg/kg L-NAME and a mixture of the same doses of L-arginine and L-NAME on the third, fourth and fifth days of pregnancy. On day 18 of pregnancy, we anesthetized the rats, excised the cerebellum after craniotomy and fixed the organs in 10% formalin. We later prepared 5 to 6-micron in thickness tissue sections and dyed them by the routine Hematoxylin and eosin (HE) and Masson's Trichrom staining methods before studying them by light microscopy.
Results: There was a significant difference between the rats receiving L-arginine and the rats in other groups (P<0.01).
Conclusion: This study showed that L-NAME is capable of significantly decreasing the injury caused by nitric oxides in rat cerebellum.

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Background: Breast cancer is one of the most important causes of death in women. One of the various gene expression involved in breast cancer is human epidermal growth factor receptor 2 (HER2/neu) gene expression increases. Factors of dietary affect on regulation of hormone secretion and the rate of breast cancer. One of these factors is amount and type of fats in diet. Gamma-linolenic acid (GLA) and Docosah-exaenoic acid (DHA) are members of poly unsaturated fatty acids. In this study, effects of dietary GLA and DHA alone or together with paclitaxel on treatment of mice mammary carcinoma has been evaluated.
Methods: Thirty female balb/c mice were divided in six groups randomly. Carcinoma-tous mass induced by tumor implantation method. Spontaneous breast adenocarcinoma of mice were used as tumor stock. The tumors of these mice were removed aseptically, dissected into 0.5 cm3 pieces. These pieces were transplanted subcutaneously into their right flank. GLA and DHA added to the mice diet two week prior to tumor implanta-tion. At the end of intervention, tumors were removed and HER2 gene expression was measured. The weight of animal and tumor volume measured weekly.
Results: It was not significant change in the weight of animals that consumed DHA and DHA with taxol. Tumor volume in those groups that received corn oil with taxol (P<0.01), DHA (P<0.05) and DHA with taxol (P<0.001) showed significant decrease in comparison with control group. HER2 gene expression in DHA with taxol decreased significantly in comparison with control group (P<0.05).
Conclusion: Consumption of DHA oil with taxol causes decrease the volume of carcin-oma mass. The future studies with large number of sample is needed to support this finding.