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J Poortmans

Publications and source records attributed to J Poortmans.

27 records · Page 2Linked to original sources
PubMed1968

Quantitative immunological determination of 12 plasma proteins excreted in human urine collected before and after exercise.

Urine was collected from 6 healthy male adults at rest and from 20 male adults after a marathon race (25 miles). The concentrated urines were quantitatively analyzed, by single radial immunodiffusion, for their content in 12 different plasma proteins: tryptophan-rich prealbumin, albumin, alpha(1)-acid glycoprotein, alpha(1)-antitrypsin, ceruloplasmin, haptoglobin, Gc-globulin, transferrin, hemopexin, beta(2)-glycoprotein I, gammaA-globulin, and gammaG-globulin.Albumin, gammaA-globulin, and gammaG-globulin represent the major part of the plasma proteins detected in normal urine excreted by humans at rest (12, 0.5, and 2.5 mg respectively, out of a total excretion of 17.5 mg of plasma proteins per 24 hr). The other plasma proteins were excreted at a lower rate (< 0.4 mg/24 hr). The relative content of tryptophan-rich prealbumin, alpha(1)-antitrypsin, Gc-globulin, transferrin, and gammaG-globulin was lower in normal urine than in normal serum, whereas that of alpha(1)-acid glycoprotein, beta(2)-glycoprotein I, and gammaA-globulin was higher. The ratio of gammaG-globulin to gammaA-globulin was 4.9:1. When plotted on a logarithmic scale, no direct relationship between the molecular weight of a protein and the value of its renal clearance could be observed.Strenuous exercise increased (up to 50-fold) the excretion of plasma proteins which represent 82% of the total proteins found in urine, instead of 57% in urine collected from humans at rest. There was particularly a significant rise of tryptophan-rich albumin, albumin, alpha(1)-acid glycoprotein, transferrin, gammaA-globulin, and gammaG-globulin (0.26, 127, 11.8, 3.3, 1.2, and 2.0 mug respectively, out of a total excretion of 167 mug of plasma proteins per min). The ratio of gammaG-globulin to gammaA-globulin was 16:1. After exercise, the renal clearance of proteins increased from 2 to 40 times, but, as for the urine of normal subjects at rest, no direct relationship between molecular weight and renal clearance could be observed.

Albuminuria↗
PubMedDate not supplied

Urinary excretion of total proteins, albumin, and beta 2-microglobulin during rest and exercise in diabetic adolescents with and without retinopathy.

To determine whether protein excretion during exercise is an earlier sign of renal dysfunction in diabetic adolescents than the basal measurements, urinary creatinine, total proteins, albumin, and beta 2-microglobulin were studied before, immediately after, and 30 min after exercise until exhaustion on a bicycle ergometer in a group of 21 adolescent diabetic boys (Albustix negative) and in a comparable control group. Among the 21 diabetic subjects, 11 had an incipient retinopathy diagnosed by fluorescein angiography. Urinary output of creatinine was similar in diabetic and in nondiabetic groups, and did not vary during exercise. At rest, the urinary output of total proteins, albumin, and beta 2-microglobulin was significantly higher in diabetic subjects than in controls. These data suggest that the subclinical proteinuria of diabetes is of mixed origin, being both glomerular and tubular. An exercise test leading to exhaustion did not give any additional information other than the basal excretion. There was no difference between diabetic subjects with early retinal vascular changes and those free from all retinopathy.

Adolescent↗