Role of sympathetic nervous system in cyclosporine-induced rise in blood pressure

Differential effects of acute and sustained cyclosporine and tacrolimus on sympathetic nerve activity

BACKGROUND

We studied the effect of acute and sustained cyclosporine and tacrolimus on muscle sympathetic nerve activity (MSNA) in groups of healthy male volunteers.

METHODS AND RESULTS

Acute cyclosporine in normal dose (2.5 mg/kg) increased MSNA from 11 +/- 6 to 19 +/- 8 bursts/min (P < 0.05). Acute cyclosporine in high dose (10 mg/kg) increased MSNA from 13 +/- 6 to 25 +/- 4 bursts/min (P < 0.05) and increased heart rate and mean arterial pressure (heart rate from 64 +/- 8 to 74 +/- 6 b.p.m., MAP from 92 +/- 10 to 105 +/- 8 mmHg; both P < 0.05). Sustained cyclosporine (2.5 mg/kg b.i.d. for 2 weeks) suppressed MSNA from 14 +/- 6 to 8 +/- 7 bursts/min (P < 0.05). Blood pressure increased from 89 +/- 6 to 98 +/- 6 mmHg (P < 0.05). Body weight increased and plasma renin activity was suppressed. Acute tacrolimus in regular dose (0.05 mg/kg) and high dose (0.20 mg/kg) had no effect on MSNA and blood pressure. Sustained tacrolimus (0.05 mg/kg b.i.d. for 2 weeks) had no effect on blood pressure, body weight and plasma renin activity, but decreased MSNA from 14 +/- 6 to 8 +/- 5 bursts/min (P < 0.05).

CONCLUSION

Sympathetic overactivity plays a role in the acute hypertensive action of cyclosporine. Cyclosporine given during 2 weeks increases blood pressure and suppresses MSNA, possibly by volume retention. Tacrolimus, in the presently applied dosages, does not cause hypertension or sympathetic overactivity. However, sustained tacrolimus also suppresses sympathetic activity, the reason of which is unclear.

Correction of renal hypertension after kidney transplantation from a donor with Gitelman syndrome

The relationship between the kidney and blood pressure control is complex. Monogenetic forms of hypertension have recently been identified that implicate specific mutations responsible for blood pressure control. The thiazide sensitive Na-Cl cotransporter (NCC) has been implicated in the control of blood pressure, however a direct link between the kidney NCC and blood pressure regulation is lacking. Here, we report a case of chimerism in which a kidney from a patient with Gitelman syndrome was transplanted into a non-Gitelman hypertensive recipient. After transplantation, postural hypotension resulted, necessitating discontinuation of all antihypertensive medications used for treatment of calcineurin-induced hypertension. This is the first reported case of acquired Gitelman syndrome after transplantation. Transplantation of a Gitelman "kidney" into a hypertensive recipient provides additional support for the role of the kidney NCC in blood pressure regulation. Furthermore, this case suggests the potential use of thiazide diuretics in the treatment of calcineurin-induced hypertension.

Effect of preventive and regressive isosorbide 5-mononitrate treatment on catecholamine levels in plasma, platelets, adrenals, left ventricle and aorta in cyclosporin A-induced hypertensive rats

Increased vascular reactivity associated with cyclosporin A (CsA)-induced arterial hypertension might result from increased vasoconstriction and/or decreased vasodilatation. The administration of organic NO donors could have beneficial effects by the NO-cGMP reposition, but there is the risk of sympathetic nervous system worsening by neuro-hormonal counter-regulation. We evaluate the effect of preventive and regressive (curative) isosorbide 5-mononitrate (Is-5-Mn) treatment on blood pressures and on plasma, platelets, adrenals, left ventricle and aorta norepinephrine (NE) and epinephrine (E) contents, assessed by HPLC, in CsA-induced hypertensive rats. Five rat groups were tested: control (orange juice), CsA (5 mg/kg/day) and Is-5-Mn (150 mg/kg/day, bid) groups were treated for 7 weeks; preventive group (Is-5-Mn+CsA): Is-5-Mn during 2 weeks plus 7 weeks of Is-5-Mn+CsA; regressive group (CsA+Is-5-Mn): CsA during 7 weeks plus 5 weeks of CsA+Is-5-Mn. The increased BP in the CsA group was prevented, but was not reverted, by concomitant Is-5-Mn treatment. In the CsA-treated rats, there was a noticeable decrease in left ventricle NE and E contents and aorta NE levels and a moderate increase in circulating catecholamines, without significant effect in the adrenals values. When Is-5-Mn was preventively used, the CsA-induced effect on left ventricle and aorta was prevented. Concomitantly, however, the plasma-platelet catecholamine balance was disrupted, accumulating NE in plasma, whereas E increased in aorta, mimic the single Is-5-Mn-treated group. In opposition, in the group used as regressive Is-5-Mn therapy, the adrenals contents were higher compared with the CsA-group and, simultaneously, the CsA-evoked effects on circulating, left ventricle and aorta catecholamines were not reverted. In conclusion, regressive Is-5-Mn therapy was unable to attenuate CsA-induced catecholamine changes and BP values even worsened. On the contrary, preventive Is-5-Mn treatment prevented the catecholamine changes on left ventricle and aorta, but increased plasma NE and aorta E accumulation. Even though with those effects, hypertension development was totally prevented, suggesting that peripheral SNS per se cannot fully explain CsA-induced hypertension. Furthermore, Is-5-Mn might produce beneficial effects only if preventively employed but, considering the changes on peripheral catecholamine contents, a judicious evaluation of the nitrate therapy impact is recommended in order to avoid further deleterious effects.

Salt sensitivity of blood pressure in patients with psoriasis on ciclosporin therapy

BACKGROUND

Hypertension is one of the main side-effects of long-term therapy with ciclosporin. However, the influence of salt intake on the 24-h mean blood pressure of patients with psoriasis treated with ciclosporin is not known.

OBJECTIVES

To evaluate, in patients with psoriasis, the sodium sensitivity of the ciclosporin-induced rise in blood pressure.

METHODS

The 24-h ambulatory blood pressure was evaluated in 13 patients with psoriasis (age range 20-57 years) in two phases, before (phase I) and after the completion of 4 months of therapy with ciclosporin 3 mg kg(-1) daily (phase II). In both phases, the patients were studied in conditions of low sodium (LS) intake followed by a high sodium (HS) diet.

RESULTS

Twenty-four-hour mean +/- SD blood pressure during LS and HS intake was, respectively, 86.3 +/- 1.6 mmHg and 85.5 +/- 1.8 mmHg during phase I, and 88.5 +/- 1.5 mmHg and 91.8 +/- 2.2 mmHg (P < 0.001 vs. phase I, HS; P < 0.05 vs. phase II, LS) during phase II. The median (interquartile range) sodium sensitivity index was greater during phase II than during phase I: - 0.0028 (- 0.0071 to 0.0009) vs. 0.0065 (- 0.0055 to 0.0258) (P < 0.02). The plasma levels and the daily urinary excretion of noradrenaline did not differ between phases I and II.

CONCLUSIONS

The ciclosporin-induced rise in blood pressure is sodium sensitive. It is also suggested that sympathetic activation is not involved in the pathogenesis of ciclosporin-induced rise in blood pressure.

Impact of Cardiac Transplantation in 24 Hours Circadian Blood Pressure and Heart Rate Profile

OBJECTIVE

The aim of the present study was to evaluate 24 hours blood pressure (BP) and heart rate changes as well as 24-hour circadian BP rhythm of cardiac transplant recipients.

METHODS

Twenty-five transplant recipients and twenty-five healthy volunteers underwent 24-hour ambulatory BP monitoring. Parameters of 24-hour ambulatory BP monitoring (24-h/daytime/nightime systolic, diastolic BP, pulse pressure, and heart rate) were determined in all patients.

RESULTS

Clinic systolic/diastolic BP, mean 24-h systolic/diastolic BP, mean daytime systolic/diastolic BP, mean nighttime systolic/diastolic BP, and mean 24-h/daytime/nighttime heart rate were significantly higher in transplant recipients than in control group subjects. Standard deviations of 24-h/daytime/nighttime heart rates were significantly lower in transplant recipients. Dippers were 48% of the control and only 12% of the transplantation group.

CONCLUSIONS

Cardiac transplant recipients had increased ambulatory BP. They also had increased 24-h/daytime/nighttime heart rate and decreased heart rate variability. Also, diminished nocturnal decrease of BP was found in transplant recipients.

Is ABPM clinically useful after pediatric solid organ transplantation?

When ambulatory blood pressure monitoring (ABPM) is performed in populations with a high risk for secondary hypertension, such as solid organ transplant recipients, hypertension or abnormalities in circadian blood pressure variability are often discovered even in patients with normal office blood pressure (BP). To discuss whether ABPM should be routinely assessed in pediatric solid organ recipients, the available information on pathological findings, association of ABPM abnormalities with outcome parameters, and treatment options is reviewed. ABPM is a useful tool to optimize therapy in the large proportion of transplant recipients with confirmed hypertension. Whether the use of ABPM on a routine basis should be recommended for pediatric transplantation patients without office hypertension remains to be determined.

Peripheral nerve function in patients with familial amyloid polyneuropathy after liver transplantation

To evaluate the therapeutic efficacy of liver transplantation in patients with ATTR Val30Met familial amyloid polyneuropathy (FAP), were repeatedly examined the neurophysiological function of peripheral nerves in nine patients. The maximal motor and sensory conduction velocities (MCV and SCV) of the ulnar and tibial nerves, size of compound muscle action potential (CMAP), terminal latency of CMAP, skin temperature of extremities, CVR-R, blood pressure, heart rate, and Schellong's test were examined before and every 6 months after the operation. Although there were no changes in CVR-R, blood pressure, or heart rate, the skin temperature of foot and hand increased soon after surgery and did not decrease during the period of observation. The temperature-adjusted MCV of tibial nerve gradually increased, but the MCV of ulnar nerve showed no change. The temperature-adjusted tibial nerve SCV worsened slightly soon after transplantation and remained at that level in the distal part. The ulnar nerve SCV worsened and subsequently improved. Liver transplantation is very effective for halting the progression of this type of FAP, but the recovery of peripheral nerve function in patients seems to be very slow and limited, especially the function of large diameter myelinated fibers.

Cardiovascular risk factors in renal transplant patients: cyclosporin A versus tacrolimus

The hypertensive and hyperlipidemic effects of cyclosporin A (CsA) may contribute to the high cardiovascular morbidity in renal transplant patients and to the development of chronic transplant nephropathy. Tacrolimus is reported to have less effect on BP and lipids, but steroids, other drugs, and renal function may confound this. This study assessed 24-h BP and lipid profile in stable renal transplant recipients (n = 17) while they were receiving CsA, after 4 wk of receiving tacrolimus, and again after 4 wk of receiving CsA. Antihypertensives were stopped at least 3 wk before. A few patients used low-dose steroids and lipid-lowering drugs, which were not changed during the study. Mean daytime BP decreased from 149 +/- 12 and 95 +/- 8 mmHg to 138 +/- 13 and 87 +/- 9 mmHg (P: < 0.001) after patients were switched to tacrolimus. Mean nighttime BP also decreased, from 140 +/- 12/86 +/- 7 mmHg to 132 +/- 17/79 +/- 10 mmHg (P: < 0.05). Total and low-density lipoprotein cholesterol decreased from 6.1 +/- 0.7 and 3.84 +/- 0.79 mmol/L to 5.1 +/- 0.8 and 2.98 +/- 0.75 mmol/L (P: < 0.001). Return to CsA caused an increase in BP and cholesterol to values similar as during the first CsA period. The conclusion is that tacrolimus has fewer unfavorable effects on BP and lipids than does CsA. Elective conversion from CsA to tacrolimus in stable renal transplant recipients may lead to attenuation of cardiovascular morbidity and chronic transplant nephropathy in the long term.