Glucosamine increases 35SO4 incorporation in vivo. To determine if glucosamine can increase tissue PG, mice were injected with glucosamine (intraperitoneal, 100 ul containing 5 mg, every other day for 3 days). On the day of the experiment 35SO4 was injected intravenously and mice were sacrificed after 4 h. Following perfusion with saline, liver, and heart were removed and homogenized in phosphate buffered saline containing 1 mM PMSF, 1 mM benzamidine and 0.5% CHAPS. PG were precipitated with 3 volumes of 100% alcohol. 35S-cpm in the precipitate was determined.