The renal metabolism of pepsinogen A and C in man.
Pepsinogen A (PGA) and pepsinogen C (PGC) are almost identical low molecular weight proteins with marked differences in renal handling. PGA is present in large amounts while PGC is almost absent in the urine of healthy subjects. Whether the amount of PGA in the urine represents the total amount of PGA that is extracted, is unknown. We, therefore, assessed the renal metabolism of PGA and PGC by measuring PGA, PGC and creatinine concentrations in the aorta and the right renal vein, and in the urine from patients undergoing elective heart catheterization. The renal extractions of PGA and PGC were not significantly different from the extraction of creatinine: 22%, 18% and 24%, respectively. Sixty-eight percent of PGA and 98% of PGC extracted from the circulation were metabolized by the kidney, and fractional metabolism was closely related to the fractional reabsorption of PGA and PGC from the glomerular filtrate. It is concluded that the kidney metabolizes PGA and PGC. The fractional metabolism of PGA and PGC can be calculated from the fractional reabsorption. Further studies on the renal handling of pepsinogens are warranted as they may provide information on factors affecting renal metabolism of low molecular weight proteins.
ten Kate
R W
RW
Department of Internal Medicine, Free University Hospital, Amsterdam, The Netherlands.
Pals
G
G
Eriksson
A W
AW
Donker
A J
AJ
Meuwissen
S G
SG
D000042:Absorption; D000328:Adult; D000368:Aged; D003404:Creatinine / Q000097:blood / Q000378:metabolism* / Q000652:urine; D004231:Diuresis; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010435:Pepsinogens / Q000097:blood / Q000378:metabolism* / Q000652:urine
D010435:Pepsinogens; D003404:Creatinine