Vascular ATP-dependent potassium channels, nitric oxide, and human forearm reactive hyperemia.

Vascular ATP-dependent potassium (K+ATP) channels open and contribute to reactive hyperemia (RH) in animals. The contribution of K+ATP channels to ischemic vasolidation during RH and interactions with endothelium-derived nitric oxide have not been well characterized in human subjects. RH blood flow responses (mL/dL) following 5 minutes of cuff occlusion were measured using strain-gauge plethysmography in 22 normal human subjects age 42 +/- 2 years.

Testosterone and frailty.

Although estrogen replacement therapy has become well established in the management of postmenopausal women, most physicians pay much less attention to the testosterone status of their older male patients. There is now increasing evidence that testosterone deficiency-Low Testosterone Syndrome-occurs in older men and is associated with decreased muscle strength and bone density, as well as memory problems. This article reviews the evidence for the existence of Low Testosterone Syndrome, often characterized as the male menopause or viropause, and the emerging evidence that testosterone therapy may ameliorate some of the symptoms and signs of frailty in men beyond 50 years of age.

Testosterone replacement in older hypogonadal men: a 12-month randomized controlled trial.

A decline in testicular function is recognized as a common occurrence in older men. However data are sparse regarding the effects of hypogonadism on age-associated physical and cognitive declines. This study was undertaken to examine the year-long effects of testosterone administration in this patient population.

Randomized, double-blind, placebo-controlled study of supplemental oral L-arginine in patients with heart failure.

Background: Patients with heart failure have reduced peripheral blood flow at rest, during exercise, and in response to endothelium-dependent vasodilators. Nitric oxide formed from L-arginine metabolism in endothelial cells contributes to regulation of blood flow under these conditions. A randomized, double-blind crossover study design was used to determine whether supplemental oral L-arginine can augment peripheral blood flow and improve functional status in patients with moderate to severe heart failure.