Direct effects of locally administered lipopolysaccharide on glucose, lipid, and protein metabolism in the placebo-controlled, bilaterally infused human leg.

Context: Accumulating evidence suggests that chronic exposure to lipopolysaccharide (LPS, endotoxin) may create a constant low-grade inflammation, leading to insulin resistance and diabetes. All previous human studies assessing the metabolic actions of LPS have used systemic administration, making discrimination between direct and indirect effects impossible.

Objective: We sought to define the direct, placebo-controlled effects of LPS on insulin resistance and protein and lipid metabolism in the infused human leg without systemic interference from cytokines and stress hormones.

Local administration of growth hormone stimulates tendon collagen synthesis in elderly men.

Tendon collagen content and circulating growth hormone (GH) are reduced in elderly. In a placebo-controlled, double-blinded study, we examined if local injections of rhGH enhance collagen synthesis in healthy elderly men (61 ± 1 yr). Two injections of rhGH or saline (control) were injected into each of the patient's patellar tendons, respectively.