Tubular Reabsorption of Pepsinogen A Isozymogens in Man1

2015 ◽  
pp. 93-99
Author(s):  
R. W. ten Kate ◽  
J. B. A. Crusius ◽  
A. Zwiers ◽  
A. M. Tolk ◽  
Abrahami de Melverda T. A. ◽  
...  
Keyword(s):  
Tubular Reabsorption ◽  
Pepsinogen A

Tubular reabsorption of pepsinogen isozymogens in man studied by the inhibition of tubular protein reabsorption with dibasic amino acids

1991 ◽  
Vol 80 (2) ◽  
pp. 161-166 ◽  
Author(s):  
M. A. G. J. ten Dam ◽  
A. Zwiers ◽  
J. B. A. Crusius ◽  
G. Pals ◽  
G. J. van Kamp ◽  
...  
Keyword(s):  
Body Weight ◽  
Specific Binding ◽  
Tubular Reabsorption ◽  
Radioisotope Method ◽  
Pepsinogen C ◽  
Pepsinogen A ◽  
Fractional Clearance ◽  
Arginine Hydrochloride ◽  
Identical Amino Acid Sequence ◽  
Protein Reabsorption

1. The fractional clearances of pepsinogen A (PGA), pepsinogen C (PGC) and the main PGA isozymogens, i.e. PGA-3, PGA-4 and PGA-5, were measured in 13 healthy male volunteers before and during blockade of tubular protein reabsorption by intravenous infusion of either l-arginine hydrochloride (n = 8; 0.5 g h−1 kg−1 body weight) or an equimolar amount of l-lysine hydrochloride (n = 5; 0.44 g h−1 kg−1 body weight). Glomerular filtration rate was measured by a radioisotope method. 2. The fractional baseline clearance of PGC (1 ± 1%) was lower than that of PGA (20 ± 10%). In addition, the fractional clearance of the PGA isozymogens appeared to be different: the fractional clearance of PGA-5 (7 ± 3%) was lower than that of PGA-4 (18 ± 9%), and the fractional clearance of PGA-4 was lower than that of PGA-3 (30 ± 10%). These differences in fractional clearance between PGA isozymogens decreased during infusion of both arginine and lysine. 3. Pepsinogens are freely filtered proteins. It can therefore be concluded that the differences in fractional clearance between PGA isozymogens imply differences in tubular reabsorption. This is remarkable as PGA isozymogens are proteins with an almost identical amino acid sequence and electric charge. The disappearance of the differences in tubular reabsorption during arginine and lysine infusion suggests that PGA isozymogens differ in affinity for negatively charged binding sites in the tubular cell membrane. In order to explain the low fractional clearance of PGC compared with that of PGA and the less marked effect of arginine or lysine infusion on the fractional clearance of PGC, an additional PGC-specific binding site has to be postulated.

Renal effects of nitric oxide synthesis inhibition in cirrhotic rats

1994 ◽  
Vol 267 (6) ◽  
pp. R1454-R1460 ◽  
Author(s):  
N. M. Atucha ◽  
J. Garcia-Estan ◽  
A. Ramirez ◽  
M. C. Perez ◽  
T. Quesada ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Renal Excretion ◽  
Renal Plasma Flow ◽  
Tubular Reabsorption ◽  
Nitric Oxide Synthesis ◽  
Important Mediator ◽  
Experimental Liver Cirrhosis ◽  
Endogenous Nitric Oxide ◽  
And Control ◽  
Experimental Liver

In the present study, we have characterized the renal response to inhibition of endogenous nitric oxide (NO) synthesis [intravenous NG-nitro-L-arginine methyl ester (L-NAME) for 3 h] in anesthetized cirrhotic rats, with (ASC) and without (CIR) ascites, at doses that do not change blood pressure (BP). Administration of L-NAME induced opposite effects on water (UV) and sodium (UNaV) excretion in cirrhotic and control animals. Infusion of 1 microgram.kg-1.min-1 of L-NAME in CIR (n = 5) decreased renal plasma flow (RPF) at the end of the 3-h period, whereas UV, UNaV, and glomerular filtration rate (GFR) were unaltered. In contrast, infusion of L-NAME at 10 micrograms.kg-1.min-1 in six more CIR increased UV and UNaV significantly by the 1st h, without changes in BP or GFR, and these parameters remained elevated throughout the experiment. Infusion of 1 microgram.kg-1.min-1 in ASC (n = 6) did not change BP or GFR but significantly enhanced UV and UNaV after the 1st h. These effects were prevented by pretreatment with L-arginine (0.1 mg.kg-1.min-1) in another group of ASC infused with 1 microgram.kg-1.min-1 of L-NAME. These results indicate that, in ASC and CIR cirrhotic rats, inhibition of NO synthesis at nonpressor does improves renal excretion of sodium and water via a decrease in tubular reabsorption. NO is an important mediator of the renal excretory and hemodynamic alterations of experimental liver cirrhosis.

Renal excretion of cephapirin and cephaloridine: Evidence for saturable tubular reabsorption

1979 ◽  
Vol 25 (6) ◽  
pp. 870-876 ◽  
Author(s):  
Annie Arvidsson ◽  
Olof Borgå ◽  
Gunnár Alvan
Keyword(s):  
Renal Excretion ◽  
Tubular Reabsorption

Lack of effect of chronic renal denervation on altered sodium reabsorption during increased ureteral pressure

1980 ◽  
Vol 58 (5) ◽  
pp. 477-483 ◽  
Author(s):  
D. R. Wilson ◽  
M. Cusimano ◽  
U. Honrath
Keyword(s):  
Isotonic Saline ◽  
Urine Osmolality ◽  
Tubular Reabsorption ◽  
Renal Nerves ◽  
Sodium Reabsorption ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Water Excretion ◽  
Renal Nerve Activity

The role of the renal nerves in the altered sodium reabsorption which occurs during increased ureteral pressure was studied using clearance techniques in anaesthetized rats undergoing diuresis induced by isotonic saline infusion. In rats with a sham denervated kidney, an ipsilateral increase in ureteral pressure to 20 cm H2O resulted in a marked and significant decrease in sodium and water excretion, increased fractional sodium reabsorption, and increased urine osmolality with no significant change in glomerular filtration rate. A similar significant ipsilateral increase in tubular reabsorption of sodium occurred in rats with chronically denervated kidneys during increased ureteral pressure. The changes in tubular reabsorption were rapidly reversible after return of ureteral pressure to normal. These experiments indicate that enhanced tubular reabsorption of sodium during an ipsilateral increase in ureteral pressure is not mediated by increased renal nerve activity. During the antinatriuresis of increased ureteral pressure there was a decrease in the fractional reabsorption of sodium from the opposite normal kidney. The role of the renal nerves in this compensatory change in function in the opposite kidney was studied in two further groups of animals. The renal response to a contralateral increase in ureteral pressure was similar in denervated and sham-denervated kidneys. The results indicate that altered renal nerve activity, through ipsilateral or contralateral renorenal reflexes, is not responsible for the changes in tubular reabsorption of sodium which occur during increased ureteral pressure induced by partial ureteral obstruction.

Sign in / Sign up

Export Citation Format

Share Document