No abstract

Physiologic testosterone administration increases lean body mass and improves quality of life among androgen-deficient men with the AIDS wasting syndrome.

Most knowledge about absorptive colonic function in man is derived from the study of patients with ileostomies (1,2) and the comparison of results with the composition of stools of normal subjects. To obtain more direct and quantitative information concerning water and salt absorption from the intact and healthy human colon, the following studies were performed. METHODSThe subjects were healthy male volunteers aged 20 to 30 years. The cecum was intubated from above with a polyvinyl tube 1.8 mm in internal diameter, with a small rubber bag containing mercury affixed to its distal end. During the 3 to 4 days required for the tube to reach the colon the subject ingested clear liquids only. After the tip was located radiologically in the cecum, a radiopaque water-soluble solution was instilled to ascertain that no reflux into the ileum would take place. Thereafter, the colon was cleaned thoroughly by perfusing it with normal saline until the material expelled rectally was clear and relatively free of mucus. After this cleansing period, 2 hours were allowed for the subjects to expel or absorb the saline remaining in the colon.All studies were performed after an 8 hour fast. The standard procedure consisted of infusing the test solution at a constant rate of 10 ml per minute into the cecum and collecting the perfusate through a rectal tube (size Fr. 24) placed into the rectum approximately 8 cm above the anus. The test solution contained 0.85 per cent sodium chloride, 1 per cent polyethelene glycol (PEG), a nonabsorbable reference substance with a molecular weight of about 4,000 (3-6), and tritiated water (0.5 to 1.0 mc per 1,000 ml). In three studies the design of the experiment was modified slightly by intubating the colon with a double polyvinyl tube and collecting samples from the mid-colon as well as from the rectal tube. Drainage from the collecting tubes was dis-* This investigation was supported by research grant 1 The symbols used in the equations are: Vi, = volume infused, ml per minute; PEG,. = PEG concentration in mg per 100 ml in infused fluid; PEGre = PEG concentration in mg per 100 ml in recovered sample; SA1, = specific activity of the radioactive tracer in the infused fluid, counts per minute per ml; SA,. = specific activity of the radioactive tracer in the recovered sample, counts per minute per ml; E1t = concentration of electrolyte in infused fluid, mEq per ml; Ere = concentration of electrolyte in recovered sample, mEq per ml. 1754

No abstract