Objectives: Haemodialysed patients with chronic renal failure are characterized by elevated plasma neuropeptide Y (NPY) concentration. Successful kidney transplantation is followed by a regression of the uraemic state and normalization of hormonal and metabolic abnormalities. The aim of the present study was to assess the influence of successful kidney transplantation on plasma NPY concentration in patients with chronic renal failure.
Methods: A total of 38 patients with chronic renal failure was examined after successful kidney transplantation. The control group consisted of 33 healthy subjects. In kidney transplant recipients plasma NPY concentration was assessed immediately before kidney transplantation and additionally two times after successful kidney transplantation: 2-4 days after surgical procedure and just before discharge of the patient from the hospital, when the graft excretory function was satisfactory. At the days specified above blood samples for NPY estimation were withdrawn at 8.00 am, 4.00 pm and 12.00 pm.
Results: Plasma NPY concentration in patients before kidney transplantation was significantly (p<0.001) higher than in healthy subjects. Plasma NPY concentration assessed at 8.00 am, 4.00 pm and at 12.00 pm both 2-4 days after kidney transplantation and one day before discharge of the patient from hospital was significantly higher than in healthy subjects (p<0.001). Plasma NPY concentration in kidney transplant patients just before discharge of the patient from hospital did not differ from 2-4 days after surgical procedure. Both in graft recipients and in healthy individuals no significant diurnal changes in NPY plasma concentration were noticed. No significant correlation was found between plasma NPY concentration and blood pressure in kidney transplant patients and in healthy subjects.
Conclusion: As successful kidney transplantation does not normalize plasma NPY concentration in the early posttransplant period, implies that the transplanted kidney with good excretory functions and immunosupressive therapy are not essential factors involved in the maintence of elevated NPY plasma level in the early posttransplant period.