Renal tubular Na(+)-K(+)-ATPase in diabetes mellitus: relationship to metabolic abnormality.
This study was undertaken to evaluate the effect of long-term diabetes on Na(+)-K(+)-ATPase in isolated nephron segments in five groups of rats: 1) controls of 7 wk duration (7 WD), 2) diabetes mellitus (DM) of 7 WD, 3) DM of 7 WD treated with insulin replacement, 4) DM rats of 25 WD, and 5) control rats of 25 WD. The blood glucose (BG) values in the first three groups were 123 +/- 9, 450 +/- 25, and 302 +/- 30 mg/dl; the glomerular filtration rate (GFR) was 1.34 +/- 0.08, 1.80 +/- 0.10, and 1.77 +/- 0.08 ml/min; and urinary sodium excretion was 0.94 +/- 0.05, 1.76 +/- 0.10, and 1.40 +/- 0.07 mu eq/min. Na(+)-K(+)-ATPase in group 2 increased in all segments studied (P < 0.001, group 1 vs. 2 for all). In group 3, Na(+)-K(+)-ATPase normalized in proximal convoluted (PC), proximal straight (PS), and distal convoluted (DC) tubules (P < 0.001, group 2 vs. group 3 for all), whereas in the outer medullary thick ascending limb (OMTAL) the correction was partial and in the CTAL and CCD there was no correction. In group 4 BG was 420 +/- 20 mg/100 ml compared with 123 +/- 9 in group 5 (P < 0.001), and GFR was 1.19 +/- 0.11 ml/min vs. 1.15 +/- 0.11 in group 5 (P = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)
Wald
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Nephrology Service, Hadassah University Hospital, Jerusalem, Israel.
Scherzer
P
P
Rasch
R
R
Popovtzer
M M
MM
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology* / Q000378:metabolism*; D005919:Glomerular Filtration Rate; D007684:Kidney Tubules / Q000201:enzymology*; D008138:Loop of Henle / Q000201:enzymology; D008297:Male; D009399:Nephrons / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D001786:Blood Glucose; D000254:Sodium-Potassium-Exchanging ATPase