American journal of physiology. Regulatory, integrative and comparative physiology
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Am. J. Physiol. Regul. Integr. Comp. Physiol. · Oct 2009
The role of nitric oxide in the development of neurogenic pulmonary edema in spinal cord-injured rats: the effect of preventive interventions.
Neurogenic pulmonary edema (NPE) is an acute life-threatening complication following an injury of the spinal cord or brain, which is associated with sympathetic hyperactivity. The role of nitric oxide (NO) in NPE development in rats subjected to balloon compression of the spinal cord has not yet been examined. We, therefore, pretreated Wistar rats with the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) either acutely (just before the injury) or chronically (for 4 wk prior to the injury). ⋯ Our data indicate that NPE development is dependent upon a marked decrease of heart rate under the conditions of high blood pressure elicited by the activation of the sympathetic nervous system. These hemodynamic alterations are especially pronounced in rats subjected to acute NO synthase inhibition. In conclusion, nitric oxide has a partial protective effect on NPE development because it attenuates sympathetic vasoconstriction and consequent baroreflex-induced bradycardia following spinal cord injury.
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Am. J. Physiol. Regul. Integr. Comp. Physiol. · Oct 2009
Comparative StudyCardiac and skeletal muscle fatty acid transport and transporters and triacylglycerol and fatty acid oxidation in lean and Zucker diabetic fatty rats.
We examined fatty acid transporters, transport, and metabolism in hearts and red and white muscles of lean and insulin-resistant (week 6) and type 2 diabetic (week 24) Zucker diabetic fatty (ZDF) rats. Cardiac fatty acid transport was similar in lean and ZDF hearts at week 6 but was reduced at week 24 (-40%) in lean but not ZDF hearts. Red muscle of ZDF rats exhibited an early susceptibility to upregulation (+66%) of fatty acid transport at week 6 that was increased by 50% in lean and ZDF rats at week 24 but remained 44% greater in red muscle of ZDF rats. ⋯ Thus insulin resistance and type 2 diabetes are accompanied by tissue-specific differences in FAT/CD36 and fatty acid transport and metabolism. Upregulation of fatty acid transport increased red muscle, but not cardiac, triacylglycerol accumulation. White muscle lipid metabolism dysregulation was not observed.