Kinetic analysis of zinc metabolism in humans after simultaneous administration of 65Zn and 70Zn.

Zinc kinetics were studied and compared after oral simultaneous administration of two tracers, radioactive (65Zn) and stable (70Zn) isotope, to four normal human volunteers. Both tracers and zinc concentration were measured in plasma, red blood cells (RBC), urine, and feces for up to 78 days. Radioactive zinc was also measured by external counting over whole body, liver, and thigh.

Resting energy expenditure and body cell mass alterations in noncachectic patients with sarcomas.

Resting energy expenditure (REE), body cell mass (BCM), and body fat (BF) were measured in six male and seven female volunteers and in a homogeneous group of noncachectic patients with sarcoma, (n = 7). The patients all had large localized tumors, no history or clinical evidence of decreased food intake or weight loss, and had received no prior treatment for cancer. Indirect calorimetry (for REE), K40 analysis (for BCM), and anthropometric measurements (for BF) were performed in accordance with established methods.

Body cell mass in cancer-bearing and anorexic patients.

We used a sensitive whole body counter which measures potassium-40 (40K) to determine total body potassium and to estimate body cell mass (BCM) in 104 previously untreated patients with upper gastrointestinal malignancies, 233 normal volunteers, and 18 patients with anorexia nervosa. BCM was greater in normal males than in females. In both normal males and females, the BCM tended to decrease with age, both as an absolute measure and as a percentage of body weight.

Kinetic analysis of zinc metabolism and its regulation in normal humans.

Zinc metabolism was studied in 32 normal volunteers after oral (n = 25) or intravenous (n = 7) administration of 65Zn. Data were collected from the blood, urine, feces, whole body, and over the liver and thigh regions for 9 mo while the subjects consumed their regular diets (containing 10 mg Zn ion/day) and for an additional 9 mo while the subjects received an exogenous oral supplement of 100 mg Zn ion/day. Data from each subject were fitted by a compartmental model for zinc metabolism that was developed previously for patients with taste and smell dysfunction.