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Increased brain l-arginine availability facilitates cutaneous heat loss induced by running exercise.
- Source :
-
Clinical & Experimental Pharmacology & Physiology . Jun2015, Vol. 42 Issue 6, p609-616. 8p. 2 Charts, 4 Graphs. - Publication Year :
- 2015
-
Abstract
- The effects of increased brain availability of l-arginine ( l-arg), a precursor for nitric oxide synthesis, on core body temperature ( Tcore) and cutaneous heat loss were evaluated in running rats. One week prior to the experiments, adult male Wistar rats received the following implants: a chronic guide cannula in the lateral cerebral ventricle and a temperature sensor in the abdominal cavity. On the day of the experiments, the rats were assigned to receive a 2- μL intracerebroventricular injection of either NaCl (0.15 mol/L) or l-arg solution (0.825, 1.65 or 3.30 mol/L); Tcore and tail skin temperature were measured while the rats ran at a speed of 18 m/min until they were fatigued. l-arginine induced a dose-dependent reduction in the threshold Tcore required for cutaneous heat loss (38.09 ± 0.20°C for 3.30-mol/L l-arg vs 38.61 ± 0.10°C for saline; P < 0.05), which attenuated the exercise-induced hyperthermia. Although the rats treated with l-arg presented a lower Tcore at the end of exercise (~0.7°C lower after treatment with the highest dose), no changes in the time to fatigue were observed relative to the control trial. These results suggest that brain l-arg controls heat loss during exercise, most likely by modulating the sympathetic vasoconstrictor tonus to skin vessels. Furthermore, despite facilitating cutaneous heat loss mechanisms, increased brain l-arg availability did not enhance physical performance. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03051870
- Volume :
- 42
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- Clinical & Experimental Pharmacology & Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 103031300
- Full Text :
- https://doi.org/10.1111/1440-1681.12407