Examining the role of beta2-adrenergic receptors in mediating exercise hyperemia in males and females during isolated diaphragm and handgrip exercise in humans.

Summary

We are conducting a research study to examine how males and females regulate blood flow differently during exercise. You will be asked to participate in 3 laboratory visits. On day one, you will complete a maximal exercise test on a stationary bike to fatigue. One day 2, you will complete a breathing exercise at three different submaximal exercise intensities and four different handgrip exercise protocols at different submaximal intensities. For each exercise intensity, you will perform exercise for 2-3 minutes. On day 3 you will complete the same exercises and intensities as day 2, but you will take two oral doses of HCl propranolol: 6 hours before the visit and immediate before the visit. Esophageal balloon: a tube will be inserted through your nose and be placed in the esophagus. The tube will be a balloon that will be inflated. Diaphragm blood flow will be measured using microbubbles infused into your vein while we take images of your diaphragm with an ultrasound probe.