title: The glomerular sieving of pepsinogen A and C in man.
abstract: Pepsinogen A (PGA) and pepsinogen C (PGC) are negatively charged, low molecular weight (LMW) proteins with a striking difference in renal handling: PGA (molecular weight 43,500 daltons) shows a high fractional excretion while the fractional excretion of PGC (molecular weight 40,500 daltons) is low, presumably due to tubular reabsorption. As these data suggest a high glomerular sieving of pepsinogens, we assessed the glomerular sieving coefficient (GSC) of PGA, PGC and several other proteins from their renal extractions. For this purpose blood samples were obtained simultaneously from the aorta (A) and right renal vein (V) in nine patients undergoing an elective heart catheterization. After correction of A-V differences for diuresis with the A-V difference of transferrin, GSCs (+/- SEM) for PGA and PGC were 0.90 +/- 0.14 and 0.85 +/- 0.17, respectively, GSC of beta 2-microglobulin being 0.90 +/- 0.12. For albumin and IgG, known to have a low GSC, low values were found. It is concluded that the GSC of a LMW protein in man can be calculated from both its A-V difference over the kidney and the A-V difference of an inert marker with a GSC of 1, provided they are corrected by the A-V difference of an inert marker with a GSC of 0. Our results demonstrate that PGA and PGC are almost freely filtered through the glomerular basement membrane despite their size and negative net molecular charge.
authors: Department of Internal Medicine and Gastroenterology, Free University Hospital, Amsterdam, The Netherlands.
authors: R W
authors: RW
authors: ten Kate
authors: G
authors: G
authors: Pals
authors: J C
authors: JC
authors: Res
authors: G J
authors: GJ
authors: van Kamp
authors: F W
authors: FW
authors: Verheugt
authors: J C
authors: JC
authors: Pronk
authors: A J
authors: AJ
authors: Donker
authors: A W
authors: AW
authors: Eriksson
authors: S G
authors: SG
authors: Meuwissen
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria; D001485:Basement Membrane / Q000502:physiology; D003401:Creatine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007074:Immunoglobulin G; D007678:Kidney Glomerulus / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009961:Orosomucoid / Q000378:metabolism; D010435:Pepsinogens / Q000032:analysis*; D012709:Serum Albumin / Q000032:analysis; D014168:Transferrin / Q000032:analysis; D000511:alpha-Macroglobulins / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D007074:Immunoglobulin G; D009961:Orosomucoid; D010435:Pepsinogens; D012709:Serum Albumin; D014168:Transferrin; D000511:alpha-Macroglobulins; D001613:beta 2-Microglobulin; D003401:Creatine