FIG. 4.

Urinary excretion of phosphorus. Urine was collected over 24 h to estimate the total daily urinary excretion of phosphorus per kilogram of body weight (A), the phosphorus concentration/creatinine concentration ratio (B), and the fractional excretion (FE) value for phosphorus relative to that for creatinine (C). Control data for total daily urinary excretion and the phosphorus concentration/creatinine concentration ratio were obtained from a total of 17 urine samples collected from 11 untreated age-matched animals (age range, 29 to 57 months; three animals were sampled multiple times); fractional excretion values were based on 14 observations for 8 of these untreated animals. Two animals (animals 31121 and 31122) receiving low-dose PMPA (10 mg/kg per day subcutaneously; Table 4) were sampled at 30, 39, 41, 45, and 54 months of age (circles, diamonds, triangles, squares, and multiplications signs, respectively), but fractional excretion values were available only for the 39-, 41-, 45-, and 54-month time points. Animal 31042, which was SIV infected and which received low-dose PMPA (10 mg/kg per day subcutaneously), was sampled at 37 and 39 months of age, with fractional excretion values available only for the 39-month time point. Animal 29046 had been on a high-dose PMPA regimen (30 mg/kg per day subcutaneously) since birth, but the daily dose was reduced to 10 mg/kg at 25 months of age and to 5 mg/kg at 78 months of age (Table 2); 24-h urine collections were performed for animal 29046 at 66 (circle), 75 (square), and 90 (triangle) months of age.