Nitroarginine

This study was undertaken to determine whether perinatal maternal resveratrol (Resv)-a phytoalexin known to confer cardiovascular protection-could prevent the development of hypertension and improve vascular function in adult spontaneously hypertensive rat offspring. Dams were fed either a control or Resv-supplemented diet (4 g/kg diet) from gestational day 0.5 until postnatal day 21. Indwelling catheters were used to assess blood pressure and vascular function in vivo; wire myography was used to assess vascular reactivity ex vivo. Perinatal Resv supplementation in dams had no effect on fetal body weights, albeit continued maternal treatment postnatally resulted in growth restriction in offspring by postnatal day 21; growth restriction was no longer evident after 5 weeks of age. Maternal perinatal Resv supplementation prevented the onset of hypertension in adult offspring (-18 mm Hg;P=0.007), and nitric oxide synthase inhibition (withl-NG-nitroarginine methyl ester) normalized these blood pressure differences, suggesting improved nitric oxide bioavailability underlies the hemodynamic alterations in the Resv-treated offspring.

Improper neuroimmune responses following chronic stress exposure have been reported to cause neuronal dysfunctions leading to memory impairment, anxiety and depression like behaviours. Though several factors affecting microglial activation and consequent alteration in neuro-inflammatory responses have been well studied, role of NO and its association with microglia in stress induced depression model is yet to be explored. In the present study, we validated combination of chronic hypobaric hypoxia and crowding (CHC) as a stress model for depression and investigated the role of chronic stress induced elevated nitric oxide (NO) level in microglia activation and its effect on neuro-inflammatory responses in brain. Further, we evaluated the ameliorative effect of L-NG-Nitroarginine Methyl Ester (L-NAME) to reverse the stress induced depressive mood state. Four groups of male Sprague Dawley rat were taken and divided into control and CHC stress exposed group with and without treatment of L-NAME.

The role of NO-ergic mechanisms in the realization of the respiratory effects of pro-inflammatory cytokine IL-1beta was investigated in acute experiments on anesthetized rats. To achieve this, we studied the effect of intravenous administration of IL-1beta during inhibition of NO-synthase by N-nitro-L-arginine methyl ester (L-NAME, a non-specific blocker of NO-synthase) on the parameters of breathing and the Hering-Breuer inspiratory-inhibitory reflex. It was shown that the effect of L-NAME eliminates the IL-1beta-dependent increase of the Hering-Breuer reflex, whereas effects on breathing pattern does not change: the increase in IL-1beta system-level evokes an increase in respiratory rate, tidal volume and lung ventilation. It is assumed that one of the mechanisms of enhance in the strength inspiratory-inhibitory reflex by increasing circulatory IL-1beta level is the increased glutamate-ergic transmission on pump-neurons induced by increase in nitric oxide synthesis in cerebrovascular endothelial cells.

We sought to explore mechanistically how intermittent high-mechanical-index (MI) diagnostic ultrasound impulses restore microvascular flow. Thrombotic microvascular obstruction was created in the rat hindlimb muscle of 36 rats. A diagnostic transducer confirmed occlusion with low-MI imaging during an intravenous microbubble infusion. This same transducer was used to intermittently apply ultrasound with an MI that produced stable or inertial cavitation (IC) for 10 min through a tissue-mimicking phantom. A nitric oxide inhibitor, L-Nω-nitroarginine methyl ester (L-NAME), was pre-administered to six rats. Plateau microvascular contrast intensity quantified skeletal microvascular blood volume, and postmortem staining was used to detect perivascular hemorrhage. Intermittent IC impulses produced the greatest recovery of microvascular blood volume (p < 0.0001, analysis of variance). Nitric oxide inhibition did not affect the skeletal microvascular blood volume improvement, but did result in more perivascular hemorrhage.