Abstract
We studied the effects of intracerebroventricular and intraperitoneal injection and the in vitro effects of Nω-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase, on the nitric oxide synthase activities of the cerebellum, brainstem, hypothalamus, hippocampus, and the remainder of the brain after dissections. Male rats were chronically implanted with lateral icv guide cannula. L-NAME was injected in doses of 0.2, 1, and 5 mg intracerebroventricularly, and 50 mg/kg intraperitoneally. L-NAME induced dose-dependent suppression of NOS activities in each brain region. The threshold dose was 0.2 mg; 1 mg L-NAME completely abolished brain nitric oxide synthase activity 90 min after the injection. Brain NOS activities returned to baseline level 48 h after the injection of 5 mg L-NAME. There were significant differences between the sensitivity of various regions to L-NAME after in vivo but not in vitro administration of the enzyme inhibitor. These findings indicate that intracerebroventricular injection of L-NAME is a useful tool for inhibiting brain nitric oxide synthase activities in vivo. The differences between the sensitivity of different brain regions to L-NAME as well as the relative fast recovery of nitric oxide synthase activities must be taken into account when L-NAME is administered intracerebroventricularly to rats.
Similar content being viewed by others
REFERENCES
Schuman, E. M., and Madison, D. V. 1994. Nitric oxide and synaptic function. Annu. Rev. Neurosci. 17:153–183.
Rees, D. D., Palmer, R. M. J., Schulz, R., Hodson, H. F., and Moncada, S. 1990. Characterization of three inhibitors of nitric oxide synthase in vitro and in vivo. Br. J. Pharmacol. 101:746–752.
Ding, J. M., Chen, D., Weber, E. T., Faiman, L. E., Rea, M. A., and Gillette, M. U. 1994. Resetting the biological clock: mediation of nocturnal circadian shifts by glutamate and NO. Science 266:1713–1717.
Watanabe, A., Hamada, T., Shibata, S., and Watanabe, S. 1994. Effects of nitric oxide synthase inhibitors on N-methyl-D-aspartate-induced phase delay of circadian rhythm of neural activity in the rat suprachiasmatic nucleus in vitro. Brain Res. 646:161–164.
Mizutani, A., Saito, H., and Abe, K. 1993. Involvement of nitric oxide in long-term potentiation in the dentate gyrus in vivo. Brain Res. 605:309–311.
Kapás, L., Fang, J., and Krueger, J. M. 1994. Inhibition of nitric oxide synthesis inhibits rat sleep. Brain Res. 664:189–196.
Kapás, L., Shibata, M., Kimura, M., and Krueger, J. M. 1994. Inhibition of nitric oxide synthesis suppresses sleep in rabbits. Am. J. Physiol. 266:R151-R157.
Krueger, J. M., Kapás, L., Kimura, M., and Opp, M. 1993. Somnogenic cytokines: methods and overview. Pages 111–129, in De Souza, E. B. (ed.), Neurobiology of Cytokines, Part B, Academic Press, San Diego, CA.
Bredt, D. S., and Snyder, S. H. 1990. Isolation of nitric oxide synthetase, a calmodium-requiring enzyme. Proc. Natl. Acad. Sci. USA 87:682–685.
Ayers, N. A., Kapás, L., and Krueger, J. M. 1996. Circadian variation of nitric oxide synthase activity and cytosolic protein levels in rat brain. Brain Res. 707:127–130.
Bagetta, G., Massoud, R., Rodinó, P., Federici, G., and Nisticó, G. 1993. Systemic administration of lithium chloride and tacrine increases nitric oxide synthase activity in the hippocampus of rats. Eu. J. Pharmacol. 237:61–64.
Iadecola, C., Xu, X., Zhang, F., Hu, J., and El-Fakahany, E. E. 1994. Prolonged inhibition of brain nitric oxide synthase by short-term systemic administration of nitro-L-arginine methyl ester. Neurochem. Res. 19:501–505.
Dwyer, M. A., Bredt, D. S., and Snyder, S. H. 1991. Nitric oxide synthase: irreversible inhibition by L-NG-nitroarginine in brain in vitro and in vivo. Biochem. Biophys. Res. Comm. 176:1136–1141.
Bannerman, D. M., Butcher, S. P., and Morris, R. G. M. 1994. Intracerebroventricular injection of a nitric oxide synthase inhibitor does not affect long-term slope potentiation in vivo. Neuropharmacoloyg 33:1387–1397.
Babbedge, R. C., Bland-Ward, P. A., Hart, S. L., and Moore, P. K. 1993. Inhibition of rat cerebellar nitric oxide synthase by 7-nitro indazole and related substituted indazoles. Br. J. Pharmacol. 110:225–228.
Hamada, J., Greenberg, J. II., Croul, S., Dawson, T. M., and Reivich, M. 1995. Effects of central inhibition of nitric oxide synthase on focal cerebral ischemia in rats. J. Cereb. Blood Flow Metab. 15:779–786.
Kovách, A. G. B., Szabó, C., Benyö, Z., Csáki, C., Greenberg, J. H., and Reivich, M. 1992. Effects of NG-nitro-L-arginine and L-arginine on regional cerebral blood flow in the cat. J. Physiol. 449:183–196.
Ichord, R. N., Helfaer, M. A., Kirsch, J. R., Wilon, D., and Traystman, R. J. 1994. Nitric oxide synthase inhibition attenuates hypoglycemic cerebral hyperemia in piglets. Am. J. Physiol. 266:H1062-H1068.
Salter, M., Duffy, C., Garthwaite, J., and Strijbos, P. J. L. M. 1995. Substantial regional and hemispheric differences in brain nitric oxide synthase (NOS) inhibition following intracerebroventricular administration of Nw-nitro-L-arginine (L-NA) and its methyl ester (L-NAME). Neuropharmacology 34:639–649.
Baydoun, A. R., and Mann, G. E. 1994. Selective targeting of nitric oxide synthase inhibitors to system y+ in activated macrophages. Biochem Biophys Res Commun. 200:726–731.
Murphy, M. E., and Noack, E. 1994. Nitric oxide assay using hemoglobin method. Methods Enzymol. 233:240–250.
Salter, M., Duffy, C., and Hazelwood, R. 1995. Determination of brain nitric oxide synthase inhibition in vitro: ex vivo assays of nitric oxide synthase can give incorrect results. Neuropharmacology 34:327–334.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ayers, N.A., Kapás, L. & Krueger, J.M. The Inhibitory Effects of Nω-Nitro-L-Arginine Methyl Ester on Nitric Oxide Synthase Activity Vary Among Brain Regions in Vivo but Not in Vitro. Neurochem Res 22, 81–86 (1997). https://doi.org/10.1023/A:1027385522859
Issue Date:
DOI: https://doi.org/10.1023/A:1027385522859