Caveolae are specialized regions of the plasma membrane that concentrate receptors and associated signaling molecules critical in regulation of cellular response to transmitters and hormones. We have determined the effects of caveolin-1 (Cav-1) deletion, caveolin-1 siRNA, and caveolar disruption in mice on the signaling pathways that mediate contraction and relaxation in colonic smooth muscle a...

EARLY DETECTION of impaired relaxation has been emphasized recently for the evaluation of global and regional ventricular function in patients with heart disease. Although early relaxation abnormalities have been found in various cardiac diseases, the underlying mechanisms are not as yet fully understood. Given the recent progress in our understanding of relaxation of the heart,' these mechanis...

Defective cardiac muscle relaxation plays a causal role in heart failure. Shown here is the new in vivo application of parvalbumin, a calcium-binding protein that facilitates ultrafast relaxation of specialized skeletal muscles. Parvalbumin is not naturally expressed in the heart. We show that parvalbumin gene transfer to the heart in vivo produces levels of parvalbumin characteristic of fast s...

Five female and five male subjects with no known cardiovascular abnormalities nor any neuromuscular disorders were examined during exercise on a cycle ergometer or a 30 min immersion in warm water with and without exercise to determine the effects of immersion on cardiac output, heart rate, blood pressure, forearm blood flow, muscle blood flow, skin blood flow and muscle relaxation. Muscle rela...

Controversy abounds in the cardiac muscle literature over the rate-limiting steps of cardiac muscle contraction and relaxation. However, the idea of a single biochemical mechanism being the all-inclusive rate-limiting step for cardiac muscle contraction and relaxation may be oversimplified. There is ample evidence that Ca(2+) concentration and dynamics, intrinsic cross-bridge properties, and ev...

Controversy abounds in the cardiac muscle literature over the rate-limiting steps of cardiac muscle contraction and relaxation. However, the idea of a single biochemical mechanism being the all-inclusive rate-limiting step for cardiac muscle contraction and relaxation may be oversimplified. There is ample evidence that Ca2þ concentration and dynamics, intrinsic cross-bridge properties, and even...