Beiträge zur Physiologie des Blutzuckers. Eine Vereinfachung meiner colorimetrischen Mikromethode zur Bestimmung: des freien Blutzuckers. II. Mitteilung. Über den Gesamtzuckerwert des Blutes, über die Verteilung des freien und des Proteinzuckers auf Plasma und Blutkörperchen bei Gesunden und Diabetikern und über den Mechanismus der Insulinhypoglykämie.
Protein sugar was estimated by subtracting free sugar from total sugar. Free and combined sugar of washed corpuscles was estimated by same methods.[long dash]Results and deductions Blood corpuscles of normals and diabetics contain no free sugar, only protein sugar. In normals 0.32-0.5%, average 0.363%. In diabetics: 0.3-0.525%, av. 0.44%. Glassmann found that the ordinary acid precipitants of albumin split off some sugar from hemoglobin at room temp. Total blood sugar of normals: 0.64-1.026%, av. 0.759%. In diabetics: 0.7-1.07%, av. 0.942%. These amounts correspond with maximal free blood sugar found in literature. Evidently in diabetics the greater part of the protein sugar can be split off and set free, probably due to acid substances in blood. The author gets much higher values than formerly because acid hydrolysis without resorcin destroyed much of the sugar split off from protein. He also claims his higher figures are not due to glucosamin, because: (1) in diabetics all the protein sugar may be set free and react as carbohydrate, (2) the action of insulin as cited below, (3) whereas glucosamin-HCl as such is very stable, when combined in the molecule is easily broken up like a sugar, (4) glucosamin may not even exist as such in the protein molecule but may be formed from separate components during the splitting up process. Plasma sugar of normals: Total, 0.329-0.729%. Protein sugar, 0.151-0.580. Free sugar, 0.119-0.18%. Protein sugar of plasma is 66.5% of total plasma sugar. Protein sugar of corpuscles, 0.290-0.5%, av. 0.358%. Plasma sugar of diabetics: Total, 0.455-1.0%. Protein sugar, 0.003-0.789%. Free sugar 0.211-0.697%. Protein sugar of plasma, 39.3% of total plasma sugar. Of great interest was the finding of 0.003% protein sugar in plasma of two diabetics. Evidently the carbohydrate groups disappear from the protein molecule. Protein sugar of corpuscles, 0.372-0.525%, av. 0.439%. Insulin changes free sugar to protein sugar, increases the concentration of blood, and brings the increased protein sugar of corpuscles back to normal. Tissue cells can use sugar only when combined with protein. Insulin brings about this combination, probably by synthesis of Schiff''s bases. Insulin overcomes the acidosis which caused the splitting of sugar from protein. Free sugar is present in blood because CO2 loosely combined in plasma and corpuscles displaces part of the sugar bound to protein. The hyperglycemia of asphyxia is similarly explained. C. Funk thought that "Primary Acidosis" was often the cause and not the result of diabetes. Glassmann goes further to say that the accumulation of acid in blood splits off the carbohydrate part of the protein molecule causing hyperglycemia and glycosuria. The amino groups of the acid component of the protein molecule are de-aminized, leading to the formation of acetone bodies. Free diffusible sugar is reduced to traces or nothing in normals during starvation. However, in diabetics all the plasma protein sugar may disappear to be replaced by free sugar.