The Isoenzymes of Lactate Dehydrogenase in the Nephton of the Healthy Human Kidney

Abstract

Die Isoenzymmuster der LDH wurden in mikrosezierten anatomischen und f unktionellen Einheiten des Nephrons der gesunden Mehschenniere bestimmt. In denGlomeruli war die Aktivität von LDH-2 undLDH-5 niedrig, während die anderen Fraktionen wesentlich stärker und ungefähr gleich aktiv waren. In den gewundenen Harnkanälchen und in den Medullarstrahlen warLDH-1 die aktivste Fraktion, gefolgt von LDH-2, während nur wenig LDH-3 und fast keine Aktivität von LDH-4 und LDH-5 gefunden wurde. Zur Papille hin nahm die Aktivität von LDH-1 und LDH-2 ab, während LDH-3 und LDH-4 stärker hervortraten. Auch LDH^S nahm zu, jedoch war der höchste Einzel wert in der äußersten Spitze der Papille nur 19% der Gesamt-LDH-Aktivität. In der Menschenniere besteht kein direkter Zusammenhang zwischen Stoffwechseltyp, respiratorisch oder glykolytisch, und den LDHIsoenzymmustern. Der insgesamt niedrige Prozentsatz der LDH-5 in der Menschenniere ist bemerkenswert, und es ist schwer verständlich, daß andere Autoren bei bestimmten Nierenerkrankungen einen Anstieg der LDH-5, deren Ursprung sie in der Niere glauben, im Serum fanden.Isoenzyme patterns of LDH have been determined in micro dissected anatomical and functional units of the nephron of the healthy human kidney. In glomeruli the activities of LDH-2 and LDH-5 were low, while the other fractions were considerably more and about equally active. In convoluted tubules and medullary rays LDH-1 was the most active fraction, followed by LDH-2. There was little activity of LDH-3 and almost no activity of LDH-4 and LDH-5. Towards the papilla the activity of LDH-1 and LDH-2 decreased, while LDH-3 and LDH-4 became increasingly prominent. LDH-5 also increased, but the highest single value in the very tip of the papilla was only 19% of the total LDH activity. There ist no strict relation between the LDH-isoenzyme patterns and the type of metabolism, respiratory or glycolytic, in the human kidney. The overall low percentage of LDH-5 in the human kidney is remarkable, and makes it difficult to understand the results of other authors who found that in certain kidney diseases the activity of LDH-5, which they believe to originate from the kidney, is increased in serum.The presence of four or five isoenzymes of LDH 3 ) in the kidney and differences in blood flow, oxygen supply the human kidney has been demonstrated by several and oxygen consumption in the various areas lead one authors. While LDH-1 and/or LDH-2 were found to be to expect differences in the isoenzyme patterns in the predominant in most investigations (1-8) WIEME and structurally and functionally different parts of the MAERCKE (9) reported the lowest activities in these nephron. fractions and about equal activities in WIELAND et al. (1) and RICHTERICH et al. (5) found no and LDH-5. The very complex anatomical structure of differences in the LDH-isoenzyme patterns between cortex and medulla of the human kidney, but a separation | 1) Supported by Grant HE 03912, HE 05529 and 5-K3-GM-15, i n j ust these two areas is very coarse and does not take ...

Serum Lactate Dehydrogenase is Elevated in Ischemic Acute Tubular Necrosis but Not in Acute Rejection in Kidney Transplant Patients

“…Serum LDH was higher when the diagnosis was ischemic ATN, and above 1173 U/L, the specificity for the diagnosis of ischemic ATN even reached 100%. However, because of the low [9][10][11][12][13] The plasma membrane is impermeable to LDH unless it loses its integrity when necrosis happens. A recent study found an association between plasma LDH levels and the extent of in vivo tubular injury in mice.…”

“…The kidneys contain the highest concentration of LDH of all human organs found mostly in tubular cells. 9 Because of its abundance, elevated levels of serum LDH may serve as a marker of tubular injury. However, only few very old studies have assessed the potential use of serum LDH as a marker of tubular damage in the clinical practice.…”

Enzymology of Human Kidney

“…The separation of cortex and papilla is very coarse and does not take into account structural differences within these zones. With microdissec tion of the anatomical and functional units of the healthy human kidney and subsequent determination (cellulose acetate gel strips) of the LDH isoenzyme patterns Mattenheimer [13,89] showed low activity of LDH 2 and LDH 5 in glomeruli, while the other fractions were more and about equally active; in convoluted tubules and me dullary rays LDH 1 was the most active fraction followed by LDH 2 with little activity of LDH 3 and almost none of LDH 4 and LDH 5. Towards the papilla the activity of LDH 1 and LDH 2 decreased, while LDH 3 and LDH 4 became increasingly prominent.…”