URINARY SOLUTE TRANSPORT BY ILEAL SEGMENTS .1. EFFECTS OF NICOTINIC-ACID

This study was conducted to quantify urinary solute transport by the i leum, using an in vivo human model, and to determine the effect of nic otinic acid on this process. Patients were studied under both basal co nditions and niacin therapy. The rates of solute transport were establ ished by analysis of excretion indexes for each solute. Potassium and ammonium were absorbed by the ileum, while phosphorus, sodium and bica rbonate were secreted. The percentage excretion index of sodium and bi carbonate increased by approximately 100 and 600% respectively, causin g a significant rise in urinary pH. Although not statistically signifi cant, there was a tendency for chloride to be absorbed and for water t o pass into the bower lumen. Nicotinic acid 3 g/day had no significant effect on urinary solute transport.