Eigenschaften, Bestimmung und klinische Bedeutung von Haptoglobin

Influence of vitamin C, vitamin E and beta-carotene on the osmotic fragility and the primary antioxidant system of erythrocytes in zinc-deficient rats

The present study was designed to investigate the effect of antioxidant supplementation on the in vitro osmotic fragility of erythrocytes from zinc-deficient rats. Rats were fed either a zinc-adequate diet, zinc-deficient diet or a zinc-deficient diet enriched either with vitamin C or vitamin E or beta-carotene. Components of the primary antioxidant system of erythrocytes, parameters of hemolysis in vivo and indicators of liver injuries were also examined. In order to ensure adequate and identical food intake rats were force-fed by intragastric tube. The supplementation with antioxidants led to a marked improvement of the osmotic fragility without having influenced zinc status of the animals and components of the antioxidant system. The strongest effect was exerted by vitamin E. The rats fed the zinc-adequate diet (control group) showed unusually high values of erythrocytes osmotic fragility. Therefore there was no difference between control group and zinc-deficient group. A possible reason for this is discussed. Zinc deficiency led to a reduction of serum zinc concentration and alkaline phosphatase activity as well as to changes in the antioxidant system of erythrocytes characterized by a decrease of glutathione and an increase of glutathione S-transferase activity. Superoxide dismutase activity in serum decreased. There was no indication for hemolysis in vivo and for liver injuries.

Serum haptoglobulin changes in patients with severe isolated head injury

From a series of 74 patients with severe head injuries and massive brain lesions, we measured the changes in haptoglobulin in 33 cases. On average, the globulin was, after a short drop in the first two days, increased about three times towards the seventh day, and was still above normal after ten days. Seen together with the total alpha-2-globulin increase after head injury this rise seems mainly to be caused by the haptoglobulin changes. Haptoglobulin was found to be a good indicator of the extent of brain tissue damage. It cannot on its own be used for prediction of survival chances.

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The object of this study was that of getting additional insight into the mechanism of proteinuria through analysis of the permeability of the glomerular filter for higher molecular weight proteins in patients with proteinuria resulting from diabetic nephropathy. Fifty hospitalized patients with insulin-requiring diabetes mellitus were selected according to the presence of proteinuria and divided into two groups: group I, with or without only minor symptoms of diabetic angiopathy; group II, with moderate to severe diabetic nephropathy and retinopathy grades 1 to 3. In all patients the urinary excretion of haptoglobins (Hp) and of isoagglutins (IA) was measured, as well as the Hp level in the serum and the overall profile of serum and urine proteins. The results indicate that the urinary excretion of Hp and IA could be correlated to some extent with the severity of diabetic nephropathy, whereas the serum level of Hp failed to exhibit any clear-cut anomalies in the presence of diabetic angiopathy. In patients with severe nephropathy, the albumin/globulin ratio in the urine was increased approximately twofold over that in serum, despite a grossly unaltered profile of serum proteins. These results suggest that the "functional pore size" of the renal filter is increased in diabetic nephropathy, but that the mechanism of proteinuria also involves degradation of serum proteins during passage through the kidney.