BACKGROUND AND PURPOSE Vascular endothelial growth factor (VEGF) can induce matrix metalloproteinase (MMP)-9 activities and focal angiogenesis. We hypothesized that VEGF activation of cerebral MMP-9 would require nitric oxide participation. METHODS We compared the in vivo effects of: (1) N(G)-monomethyl-l-arginine, a nonspecific nitric oxide synthase inhibitor; (2) L-N(6)-(1-iminoethyl)lysine...

background: skin flap grafting is a popular approach for reconstruction of critical skin and underlying soft tissue injuries. in a previous study, we demonstrated the beneficial effects of two 5α-reductase inhibitors, azelaic acid and finasteride, on tissue survival in a rat model of skin flap grafting. in the current study, we investigated the involvement of nitric oxide and inducible nitric o...

BACKGROUND: In cirrhotic livers, the balance of vasoactive substances is in favour of vasoconstrictors with relatively insufficient nitric oxide. Endothelial dysfunction has been documented in cirrhotic rat livers leading to a lower activity of endothelial nitric oxide synthase but this might not be sufficient to explain the low nitric oxide presence. We compared the amount of all nitric oxide ...

Nitric oxide (NO) is involved in several biological processes, but its role in human melanogenesis is still not well understood. Exposure to UVA and UVB induces nitric oxide production in keratinocytes and melanocytes through the activation of constitutive nitric oxide synthase, increasing tyrosinase activity and melanin synthesis, whereas inducible nitric oxide synthase over expression might b...

Introduction: Nitric oxide seems to play a dual role in ischemia/reperfusion injury. Few studies have investigated whether it exacerbates or improves brain edema. In the present study, we inhibited the activity of nitric oxide synthase by L-NAME and evaluated the cerebral infarct volume, tissue swelling and brain edema, alongside the measurement of blood flow of the ischemic region. Methods...

BACKGROUND AND PURPOSE Nitric oxide has been implicated as a mediator of glutamate excitotoxicity in primary neuronal cultures. METHODS A number of indicators of brain nitric oxide production (nitric and cyclic guanosine monophosphate [cGMP] concentrations and nitric oxide synthase activity) were examined after bilateral carotid ligation and right middle cerebral artery occlusion in adult rat...

objective(s): nitric oxide (no), a product of inducible nitric oxide synthase (inos), contributes in germ cell apoptosis. this study was aimed to evaluate the effects of aloe vera gel (avg) on male wistar rat reproductive organ, serum no level, and expression of inos gene in leydig cells. materials and methods:adult male wistar rats (n=36) were used for experiments in three groups. the experime...

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Nitric oxide synthase activity was studied by means of NADPH-diaphorase activity and nitric oxide synthase immunoreactivity in the main and accessory olfactory bulbs of the frog Rana perezi and the newt Triturus marmoratus. In both species, NADPH-diaphorase staining was observed in all olfactory fibers. Vomeronasal fibers were NADPH-diaphorase-positive in Triturus but they were NADPH-diaphorase...