CALL FOR PAPERS Oxidative Stress Inhibition of nitric oxide synthase enhances superoxide activity in canine kidney

نویسندگان

  • Dewan S. A. Majid
  • Akira Nishiyama
  • Keith E. Jackson
  • Alexander Castillo
چکیده

Majid, Dewan S. A., Akira Nishiyama, Keith E. Jackson, and Alexander Castillo. Inhibition of nitric oxide synthase enhances superoxide activity in canine kidney. Am J Physiol Regul Integr Comp Physiol 287: R27–R32, 2004. First published March 25, 2004; 10.1152/ajpregu.00073.2004.—To evaluate the role of a potential interaction between superoxide anion (O2 ) and nitric oxide (NO) in regulating kidney function, we examined the renal responses to intra-arterial infusion of a superoxide dismutase mimetic, tempol (0.5 mg kg 1 min ), in anesthetized dogs treated with or without NO synthase inhibitor, N -nitro-L-arginine (NLA; 50 g kg 1 min ). In one group of dogs (n 10), tempol infusion alone for 30 min before NLA infusion did not cause any significant changes in renal blood flow (RBF; 5.2 0.4 to 5.0 0.4 ml min 1 g ), glomerular filtration rate (GFR; 0.79 0.04 to 0.77 0.04 ml min 1 g ), urine flow (V; 13.6 2.1 to 13.9 2.5 l min 1 g ), or sodium excretion (UNaV; 2.4 0.3 to 2.2 0.3 mol min 1 g ). Interestingly, when tempol was infused in another group of dogs (n 12) pretreated with NLA, it caused increases in V (4.4 0.4 to 9.7 1.4 l min 1 g ) and in UNaV (0.7 0.1 to 1.3 0.2 mol min 1 g ) without affecting RBF or GFR. Although NO inhibition caused usual qualitative responses in both groups of dogs, the antidiuretic (47 5 vs. 26 4%) and antinatriuretic (67 4 vs. 45 11%) responses to NLA were seen much less in dogs pretreated with tempol. NLA infusion alone increased urinary excretion of 8-isoprostane (13.9 2.7 to 22.8 3.6 pg min 1 g ; n 7), which returned to the control levels (11.6 3.4 pg min 1 g ) during coadministration of tempol. These data suggest that NO synthase inhibition causes enhancement of endogenous O2 levels and support the hypothesis that NO plays a protective role against the actions of O2 in the kidney.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Inactivation of extracellular superoxide dismutase contributes to the development of high-volume hypertension.

OBJECTIVES Extracellular superoxide dismutase (ecSOD) lowers superoxide anions and maintains vascular nitric oxide level. We studied the function of ecSOD in high-volume hypertension induced by the 1-kidney-1-clip model in wild-type, ecSOD-/- mice, and endothelial nitric oxide synthase (eNOS)-/- mice. METHODS AND RESULTS The 1-kidney-1-clip model resulted in impaired endothelium-dependent rel...

متن کامل

Enhanced Oxidative Stress Is Responsible for TRPV4-Induced Neurotoxicity

Transient receptor potential vanilloid 4 (TRPV4) has been reported to be responsible for neuronal injury in pathological conditions. Excessive oxidative stress can lead to neuronal damage, and activation of TRPV4 increases the production of reactive oxygen species (ROS) and nitric oxide (NO) in many types of cells. The present study explored whether TRPV4-induced neuronal injury is mediated thr...

متن کامل

Lipid Peroxidation Inhibition, Superoxide Anion and Nitric Oxide Radical Scavenging Properties of Thymus daenensis and Anethum graveolens Essential Oils

Background: Safety and efficacy of the synthetic antioxidants used in the food industry are frequently questioned because such antioxidants are unstable and highly volatile, therefore, interest in finding naturally occurring antioxidants that have the potential to protect human beings from damage induced by oxidative stress has intensified. Objective: Bioactivities of Thymus daenensis and Ane...

متن کامل

The effect of inhibition of nitric oxide synthase on aluminium-induced toxicity in the rat brain.

The goal of the present study was to examine the effectiveness of a non-specific nitric oxide synthase (NOS) inhibitor N-nitro-L-arginine methyl ester (L-NAME) to modulate the toxicity of aluminium chloride (AlCl3). Rats were killed at 3 h and at 30 days after treatments and the striatum was removed. Nitrite, superoxide, superoxide dismutase activity, malondialdehyde and reduced glutathione wer...

متن کامل

EXPRESSION OF INDUCIBLE NITRIC OXIDE SYNTHASE GENE (iNOS) STIMULATED BY HYDROGEN PEROXIDE IN HUMAN ENDOTHELIAL CELLS

Inducible nitric oxide synthase (iNOS) gene expresses a calcium calmudolin-independent enzyme which can catalyse NO production from L-arginine. The induction of iNOS activity has been demonstrated in a wide variety of cell types under stimulation with cytokines and lipopoly saccharide (LPS). Previous studies indicated that all nitric oxide synthases (NOS) activated in human umbilical vein endot...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2004