Abstract
This study aimed to contribute to the knowledge of cardiovascular regulation associated with repeated exercise by evaluating untraditional parameters in the model of voluntary wheel running. Possible changes in cardiac phenylethanolamine N-methyltransferase (PNMT) gene expression were evaluated using running for 3 weeks in four rat strains, and the hypothesis that voluntary wheel running modifies mean arterial pressure (MAP) responses to oxytocin administration was verified. Running activity increased gradually and was high in spontaneously hypertensive rats (SHR) and Sprague-Dawley rats, while low in Wistar rats. The levels of PNMT mRNA in the left but not right atrium increased significantly in rat strains exhibiting high physical activity. Concentrations of PNMT mRNA were significantly higher in SHR and Sprague-Dawley compared to those in Wistar rats, which ran much shorter distances. MAP was found to be higher in rats exposed to voluntary running, which might be the result of the cessation of the exercise 24 h before the measurements. Oxytocin treatment (5 microg/kg and 30 microg/kg i.v.) resulted in significant increase in MAP in both control and running animals in a dose-dependent manner. In conclusion, voluntary wheel running failed to modify sensitivity to cardiovascular action of oxytocin but resulted in increased gene expression of PNMT in left, but not right, heart atrium in a running activity-dependent manner.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.