QUANTITATIVE HISTOCHEMISTRY OF THE NEPHRON. III. LACTIC DEHYDROGENASE ACTIVITY IN MAN AND OTHER SPECIES*

Abstract

The quantitative distribution of lactic dehydrogenase (LDH) activity in the nephron of man, monkey, dog, rat, rabbit, frog and toadfish was studied. Considerable LDH activity was found in all parts of the nephron analyzed. In all cases the cortical tubules had higher activity than did the glomeruli. The highest levels of activity were found in the nephrons of man and dog, the lowest in the frog and the toadfish. The following results were obtained in man (expressed in moles of reduced diphosphopyridine nucleotide DPNH oxidized per kg dry weight of tissue per hour at 37[degree]C): glomeruli 106 [plus or minus] S.E. 6.1; proximal convolutions 261 [plus or minus] 9.3; distal convolutions 261 [plus or minus] 9.9; medullary ray 227 [plus or minus] 9.6; outer medullary zone 200 [plus or minus] 12; inner medullary zone 130 [plus or minus] 5.5; papilla 158 [plus or minus] 24; small artery 131 [plus or minus] 12.8. Within the cell, LDH activity was found almost exclusively in the nonparticulate cytoplasm.