CYCLOSPORINE-INDUCED STIMULATION OF THE RENIN-ANGIOTENSIN SYSTEM AFTER LIVER AND HEART TRANSPLANTATION

To analyze the status of the renin-angiotensin system in hypertensive transplant recipients on cyclosporine, we prospectively explored 21 cardiac (CTR: 52 +/- 8.2 yr) and 12 liver (LTR: 45 +/- 10 yr) transplant recipients on a normal salt diet with 19 normotensive controls in the same age range. Systolic and diastolic blood pressure was measured in the supine and standing positions. Renal function was assessed by serum creatinine values, and 24-hr urinary sodium and potassium excretion were recorded. Plasma renin activity (PRA), active renin, total renin, angiotensinogen, aldosterone, and cortisol plasma levels were simultaneously determined. Results were expressed as mean +/- SD, and between-group differences were compared using variance analysis. Supine blood pressure (+/- SD) was 158 +/- 15/103 +/- 8.4 in CTR and 155 +/- 21.4/102 +/- 11.7 mmHg in LTR. Serum creatinine was higher in CTR (159 +/- 52 mumol/L) than in LTR (117 +/- 24.7, P < 0.05) and values in both groups were above controls (83 +/- 14.1, P < 0.05). Urinary sodium excretion tended to be lower in transplant recipients (59 +/- 42 mmol/L) for CTR and 44 +/- 36.7 in LTR than in healthy controls (117 +/- 24.7 mmol/L). Supine and upright PRA values tended to be higher in hypertensive transplant recipients than in healthy volunteers, although not significantly. Supine active renin was significantly higher in CTR (47 +/- 42 pg/ml) and in LTR (44 +/- 29.8 pg/ml) than in normal subjects (17 +/- 4.8 pg/ml, P < 0.05). Total renin levels in CTR (supine: 716 +/- 357 pg/ml) and in LTR (supine: 647 +/- 365 pg/ml) were 3- to 4-fold higher than in controls (supine: 207 +/- 69 pg/ml) (P < 0.05), as were inactive renin levels (P < 0.01). Active renin was effectively correlated with PRA (P < 0.001) and with total renin (P < 0.001) in the supine and in the upright position. Plasma aldosterone was almost within the normal range in CTR and in LTR, and it did not correlate with PRA values. Plasma angiotensinogen levels were normal in LTR (1032 +/- 226 ng/ml) but were significantly lower in CTR (938 +/- 216 ng/ml, P < 0.05). Cortisol plasma levels were lower in both CTR (7 +/- 4.4 micrograms/L) and LTR (6 +/- 1.9 micrograms/L) than in healthy controls (11 +/- 4 micrograms/L, P < 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)