evidence supports the involvement of nitric oxide (no) in a varity of male reproductive processes such as spermatogenesis, spermiogenesis, sperm motion, sperm metabolism and sperm capacitation. however, low concentration of no is essential in biology and physiology of spermatozoa, but high amounts of no is toxic and has negative effects on sperm functions. on the other hand, it is established t...

background: hawthorn species decreases blood pressure and relaxes precontracted vessels. this study aimed at examining the antihypertensive effect and related mechanisms of hydroalcoholic extract of crataegus azarolus subspecies aronia fruit in rats with renovascular hypertension. methods: six groups of male sprague-dawley rats, each containing 6 to 8 rats, were studied. the groups comprised of...

background: in some disorders such as diabetes mellitus patients can display depressive symptoms. metformin is among the first-line treatments for management of the type 2 diabetes mellitus which may have some anti-depressant effect. objective: current investigation was performed to examine the anti-depressant effects of metformin and the involvement of nitric oxide (no) in this way, in an expe...

background and objective: nitric oxide (no) plays a role in thermoregulation and growth of protozoa. this work aimed to add the molecule no in physiology of protozoa in contact with abused narcotic substances. materials and methods: a sedative drug, morphine, was infused into a cell chamber containing paramecia . the cell response to the drug was recorded promptly after drug infusion using a po...

estrogen replacement therapy (ert) in postmenopausal women may decrease the risk of coronary artery diseases (cad). we hypothesized that nitric oxide (no) releasing due to ert may be the essential factor by which endothelial permeability decreases. four groups of ovariectomized rabbits were under investigation for five weeks. groups 1 & 4 received high cholesterol diet and other two groups (2 &...

introduction: repeated hyperglycemia play an important role in the development of atherosclerosis in diabetic patients. endothelium is the organ of the first-line defense against atherosclerosis and nitric oxide has a major role in this task. the aim of this study was to determine changes in plasma nitric oxide metabolites concentration during glucose tolerance test in type 2 diabetic rats. met...

helicobacter pylori infection leads to different clinical and pathological outcomes in humans, including chronic gastritis and gastric neoplasia. it has been demonstrated that oxidative stress associated with inflammation plays an important role in gastric carcinogenesis. to evaluate the oxidative stress in h. pylori infection we studied the gastric juice levels of nitric oxide and the activiti...

Nitric oxide plays a central role in the physiology and pathology of diverse tissues including the immune system. It is clear that the levels of nitric oxide must be carefully regulated to maintain homeostasis. Appropriate levels of nitric oxide derived from iNOS assist in mounting an effective defense against invading microbes. Conversely, inability to generate nitric oxide results in serious,...

BACKGROUND Inducible or neuronal nitric oxide synthase gene deletion increases or decreases anxiety-like behavior in mice, respectively. Since nitric oxide and endocannabinoids interact to modulate defensive behavior, the former effect could involve a compensatory increase in basal brain nitric oxide synthase activity and/or changes in the endocannabinoid system. Thus, we investigated the expre...

Gut microbiota has been linked to a number of human diseases including colon cancer. However, the mechanism through which gut bacteria influence colon cancer development and progression remains unclear. Perturbation of the homeostasis between the host immune system and microbiota leads to inflammation and activation of macrophages which produce large amounts of nitric oxide that acts as a genot...