The phosphatidylcholine metabolism in the renal tissue during experimental acute and chronic pyelonephritis in the rabbit.

In 139 adult male rabbits unilateral pyelonephritis (PN) was induced. In a broad spectrum of enzymes and phospholipids also the content of phosphatidylcholine (PC) was determined. Only these latter values are reported here. PC showed markedly increased levels up to the 20-d-, and to the 31-d-series in the cortex. After 64 and 100 d of experimental PN the content of PC was less than the half of the normal values, and after 261 d of disease, it was only about 1/16 of the normal value (= 22.58 +/- 1.55 micrograms P/g wet weight). In the medulla the PC increased only till the 20-d-series, but showed a marked decrease in the 31-d-series already, which is in contrast to the corresponding cortical situation. Thereafter the medullary PC decreased successively, so that only about 5 per cent of the normal value were found in the contracted kidneys of the 261-d-series (n = 13.58 +/- 1.24 microgramsP/g wet weight). The increased PC-concentrations should be due mainly to the increased cell contents, the following reductions being due to the lower cell contents of this interstitium. Other factors (induced synthesis and/or reduced decomposition) may be responsible to a lesser degree of probability. The strongly decreased PC concentrations in the chronic and late-chronic series are caused by the low cell-contents, increasing vascular changes, the augmented connective tissue, and the general epithelial damage of the remaining nephrons.