No abstract

1. Plasma sulphur-containing amino acids were measured in 19 patients with renal failure on chronic haemodialysis and in 22 normal subjects, to determine the rate of accumulation of these amino acids in chronic azotaemia. 2. Cysteine--homocysteine mixed disulphide was significantly increased in patients before dialysis and homocysteine was detected in low concentration in 10 patients. Cystine and taurine were also increased. Changes in other neutral and acidic amino acids were similar to those reported in chronic renal insufficiency. 3. In 3--4 h of dialysis serum creatinine was decreased by a mean of 55%, cysteine--homocysteine by 41% and cystine by 58.5% (P less than 0.001 for each). Methionine concentrations were normal throughout. 4. We conclude that sulphur-containing amino acids, except methionine, accumulate in chronic renal failure as rapidly as creatinine.

Earlier we demonstrated significant differences in proximal tubular Na transport inhibition during saline volume expansion (VE) depending on whether artificial (AF) or native harvested tubular fluid (HTF) was used. In the present experiments the shrinking-drop technique was used to measure volume flux (Jv) in the early- and late-clip models of VE with AF alternating with HTF. In early-clip rats, with AF, Jv (x 10(4) mm3.mm-2.s-1) during the nonexpanded period was 2.92 +/- 0.105; during subsequent VE, it was 2.20 +/- 0.180 and 1.97 +/- 0.149 with HTF (for the latter two P greater than 0.3). In late-clip rats they were 2.83 +/- 0.135, 1.99 +/- 0.157, and 1.50 +/- 0.171 (for the latter two P less than 0.001), respectively. With AF, transport was inhibited equally in both models during VE. There were no significant differences in the electrolyte composition of AF and HTF during shrinkage as measured by microprobe analysis. The 47% inhibition of Jv with HTF but not AF during VE in the late-clip but not the early-clip rats strongly implies the presence of factors other than physical forces during VE, which inhibit proximal tubular Na transport. Studies of tubular transport during VE need to be performed using both AF and HTF.

The 16-Ene Vitamin D Analogues -(synthesis and application against prostate cancer; 41 refs.). -(USKOKOVIC, M. R.; STUDZINSKI, G. P.; GARDNER, J. P.; REDDY, S. G.; CAMPBELL, M. J.; KOEFFLER, H. P.; Curr.