It's known that congestive heart failure -- the leading cause of cardiovascular disease and related death -- is associated with elevated blood levels of angiotensin II, which causes blood vessel contraction, high blood pressure and muscle wasting.

While it was recognized that weight loss caused by muscle wasting is an important predictor of poor outcomes in patients with heart failure, researchers had a poor understanding of the mechanisms underlying this association.

In previous research with rats, the Tulane scientists found that administration of angiotensin II resulted in a reduction in body weight and a decrease in levels of insulin-like growth factor-1 (IGF-1) in both blood and skeletal muscle.

In this new study, the Tulane team found that angiotensin II inhibited IGF-1 signaling in skeletal muscle. They concluded that this is casually related to the loss of skeletal muscle.

The scientists also found a complete reversal of angiotensin-induced muscle loss in mice genetically engineered to overproduce IGF-1.They found strong evidence that a specific signaling kinase pathway is involved in the ability of IGF-1 to prevent muscle loss.

SOURCE: Journal of Clinical Investigation , news release, Jan. 13, 2005