it has been shown that stress and chronic pain could prevent the development of tolerance to morphine analgesia, which appears to be related to the activation of hypothalamus–pitutitary–adrenal (hpa) axis, activation of neuroendocrine systems and changes in neurochemical levels. moreover, the involvement of nitric oxide (no) in the development of tolerance to morphine analgesia has been implica...

sub chronic exposure to lead in rats slows gastric emptying, but little is known about the effects of lead on gastric secretion. this study was designed to investigate the effects of lead on gastric acid secretion and its possible mechanisms in rats. lead acetate was dissolved in drinking water in a concentration of 1%. sodium acetate-containing water with a molar concentration similar to lead ...

introduction: infertility is a common phenomenon in modern societies. today, use of assisted reproductive technologies (arts) for treatment of infertility is common, and cryopreservation is one of these technologies. cryopreservation has impact on the function and percentage of fertility of human sperm. in this study, motility, viability, nitric oxide, and dna apoptosis were assessed before and...

nitric oxide is an important vasorelaxant factor that it inhibits platelet adhesion and proliferation of smooth muscle cells. no is synthesized from l-arginine by means of endothelial nitric oxide synthase (enos) which is an isoform of  nitric oxide synthase.in the present study, we examined  possible association between the 27 base pair (bp) repeat  polymorphism in intron 4 of the  enos3 gene ...

It has been shown that nitric oxide is synthesized in the central nervous system as well as in vascular endothelial cells. Recently, it was reported that nitric oxide was involved in central cardiovascular regulation, baroreflex modulation, and involved in a reciprocal release with excitatory amino acids in the nucleus tractus solitarii of rats. The purpose of the present study was to investiga...