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Biomedical subjects

J Kumpati

Publications and source records attributed to J Kumpati.

5 recordsLinked to original sources
PubMed1987

Liposome-loaded phenylalanine or tryptophan as sickling inhibitor: a possible therapy for sickle cell disease.

Phenylalanine or tryptophan entrapped in small unilamellar liposomes was used to transport Phe or Trp across the red blood cell membrane. The incorporation of Phe or Trp into RBCs via liposomes markedly inhibited and reversed the in vitro sickling of deoxy Hb S. Furthermore, normal and SS RBCs loaded with Phe or Trp did not exhibit significant change in osmotic fragility, mechanical fragility, autohemolysis, and glycolysis when compared to untreated RBCs. In addition, the oxygen affinity measured as the P50 and concentrations of 2,3-DPG and ATP were not affected by the incorporation of Phe or Trp into AA or SS RBCs. These results demonstrate that this liposomal transport system which transferred Phe and Trp into intact RBCs did not have any adverse effect on RBC metabolism and function, and may have therapeutic implications in the treatment of sickle cell disease.

Anemia, Sickle Cell↗
PubMed1987

Effect of phenylalanine- or tryptophan-loaded liposomes on the rheological properties of AA and SS erythrocytes.

Phenylalanine or tryptophan was incorporated into AA and SS red blood cells by a liposomal transport system which was previously shown by Kumpati to inhibit and reverse sickling of intact SS red blood cells in vitro. In the present study, the effect of phenylalanine or tryptophan incorporation on the rheological properties was evaluated. The incorporation of phenylalanine or tryptophan into red blood cells decreased the viscosity of deoxy SS red blood cells which reached a level close to that for normal red blood cells due to the antisickling effect. These results demonstrate that this liposomal transport system which transferred phenylalanine or tryptophan into intact red cells and did not have any adverse effect on red cell metabolism or function did correct the viscosity of deoxy SS red cells by its antisickling effect. This method may have significant therapeutic implications in the treatment of sickle cell disease.

Anemia, Sickle Cell↗
PubMed1982

Sickling as a function of oxygen delivery: effect of simulated transfusions of stored, fresh and inositol-hexaphosphate-loaded (low affinity) red cells.

Low oxygen affinity red cells were prepared by incorporating inositol hexaphosphate (IHP) into red blood cells (rbc) by means of a liposomal transport system. The effect of in vitro simulated exchange transfusions on sickling was studied with buffered red cell suspensions containing 50% SS cells and 50% test cells. Test rbc were either stored cells with high oxygen affinity, fresh cells with normal affinity or IHP-loaded cells with decreased affinity. Oxygen equilibrium curves and percentage sickling as a function of PO2 were determined and the data analyzed in terms of percentage sickling as a function of oxygen delivery. Our simplified analysis shows that simulated exchange transfusion with stored and, to a lesser extent even with fresh blood, results in a decreased venous PO2 and increased sickling of the remaining SS cells. In contrast, transfusion with IHP-loaded cells results in higher venous PO2 values and less sickling throughout the range of oxygen delivery. Thus, the transfusion of IHP-loaded cells may result in less sickling of the remaining SS cells in addition to the normal dilutional effect.

2,3-Diphosphoglycerate↗