[Calcium-binding properties of tissue proteins after kidney allotransplantation]

The kinetics of calcium binding to tissue substrates in hypercalcaemia, induced by intravenous constant rate infusion of calcium gluconate were studied in 19 patients after renal transplantation and in 14 healthy volunteers. Langmuir, Scatchard and Hill analysis revealed the positive cooperative mechanism of calcium binding to tissue in all patients and in healthy volunteers. These results provide indirect evidence of binding of calcium to tissue proteins. The significant decrease of the values of specific buffer capacity of tissue proteins, pool of exchangeable calcium and also the effective Ka were observed in 37% of patients. These changes are proposed to play a role in the pathological calcification of vessels and soft tissues in patients after renal transplantation.