Effects of chronic nitric oxide synthase inhibition on V'O and exercise capacity in mice.

Autor: Wojewoda, M., Przyborowski, K., Sitek, B., Zakrzewska, A., Mateuszuk, L., Zoladz, J., Chlopicki, S.
Zdroj: Naunyn-Schmiedeberg's Archives of Pharmacology; Mar2017, Vol. 390 Issue 3, p235-244, 10p
Abstrakt: Acute inhibition of NOS by L-NAME (N-nitro-L-arginine methyl ester) is known to decrease maximal oxygen consumption (V'O) and impair maximal exercise capacity, whereas the effects of chronic L-NAME treatment on V'O and exercise performance have not been studied so far. In this study, we analysed the effect of L-NAME treatment, (LN2 and LN12, respectively) on V'O and exercise capacity (in maximal incremental running and prolonged sub-maximal incremental running tests), systemic NO bioavailability (plasma nitrite (NO ) and nitrate (NO )) and prostacyclin (PGI) production in C57BL6/J mice. Mice treated with L-NAME for 2 weeks (LN2) displayed higher V'O and better running capacity than age-matched control mice. In LN2 mice, NO bioavailability was preserved, as evidenced by maintained NO plasma concentration. PGI production was activated (increased 6-keto-PGF plasma concentration) and the number of circulating erythrocytes (RBC) and haemoglobin concentration were increased. In mice treated with L-NAME for 12 weeks (LN12), NO bioavailability was decreased (lower NO plasma concentration), and 6-keto-PGF plasma concentration and RBC number were not elevated compared to age-matched control mice. However, LN12 mice still performed better during the maximal incremental running test despite having lower V'O. Interestingly, the LN12 mice showed poorer running capacity during the prolonged sub-maximal incremental running test. To conclude, short-term (2 weeks) but not long-term (12 weeks) treatment with L-NAME activated robust compensatory mechanisms involving preservation of NO2- plasma concentration, overproduction of PGI and increased number of RBCs, which might explain the fully preserved exercise capacity despite the inhibition of NOS. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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