Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclosporin A (CsA) treatment is associated with hypertension and renal dysfunction. Increased circulating endothelin (ET) has been implicated in this renal dysfunction, which is secondary to renal vasoconstriction and decreases in RBF. The effects of the selective blockade of ETA receptors or the combined blockade of ETA and ETB receptors on the acute hemodynamic response to CsA in anesthetized rats were examined. Rats were pretreated with vehicle, BQ-123 (selective ETA receptor antagonist; 0.6 micron/kg per minute), or BQ-123 and PD 142893 (combined ETA/ETB receptor antagonist; 0.6 micron/kg per minute) to achieve both ETA and ETB receptor blockade. After a 10-min pretreatment, CsA (20 mg/kg over 10 min) was administered; mean arterial blood pressure, RBF, and iliac blood flow were monitored continuously. Hemodynamic responses to exogenous endothelin-1 (ET-1, 0.3 and 1 nmol/kg) with and without antagonist pretreatment were measured in separate groups to demonstrate effective receptor blockade. CsA elevated blood pressure 17 to 20% in all three groups; renal resistance maximally increased 23, 20, and 23% in vehicle, BQ-123, and BQ-123 and PD 142893 pretreated groups, respectively. In contrast, the combination of BQ-123 and PD 142893 blocked systemic pressor responses to 0.3 and 1 nmol of ET-1 approximately 50 and 37%, respectively; changes in renal resistance were blocked 81 and 89%, respectively. In conclusion, the elevation in systemic blood pressure and the renal vasoconstrictor activity of CsA do not appear to be mediated through ETA or ETB receptors.
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PMID:Effects of selective endothelin antagonists on the hemodynamic response to cyclosporin A. 816 26

Hypertension is a frequent complication after organ transplantation in both children and adults and is a significant risk factor for the development of cardiovascular disease and graft dysfunction. There are multiple mechanisms responsible for the development of posttransplant hypertension. In the precyclosporine era, chronic rejection was the most common cause. The introduction of cyclosporine A has increased the prevalence of hypertension in solid organ transplant recipients. Cyclosporine increases renal vascular resistance by causing vasoconstriction of the afferent arteriole. From a pathophysiologic point of view, a calcium channel blocker should be used as the initial therapy in patients with cyclosporine-associated hypertension. Hypertension needs to be treated aggressively in all transplant recipients in an attempt to minimize allograft and cardiovascular damage.
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PMID:Hypertension after renal transplantation. 819 93

Chronic angiotensin-converting enzyme (ACE) inhibition prevents endothelial dysfunction in hypertension and hypercholesterolemia. Long-term treatment with cyclosporin A impairs endothelium-dependent relaxations and augments contractions to angiotensin II in the rat aorta. The present study compares vasomotor responses to several vasoconstrictor and dilator stimuli after 6 weeks of oral treatment with either the angiotensin-converting enzyme inhibitor lisinopril (10 mg/kg per day), the angiotensin subtype 1 receptor antagonist D 8731 (10 mg/kg per day), cyclosporin A (15 mg/kg per day), or a combination of cyclosporin A with lisinopril or D 8731 (n = 15 rats per group). Twenty-four hours after the last treatment, aortic rings were mounted in organ chambers for measurement of isometric force. Endothelium-dependent relaxations to acetylcholine and calcium ionophore were impaired by cyclosporin A but not affected by the vasodilators. Cyclosporin A-induced endothelial dysfunction was prevented by cotreatment with lisinopril or D 8731. Relaxations to nitroglycerin, SIN-1, and forskolin were not affected by any treatment. Contractions to phenylephrine and serotonin were reduced by lisinopril but not by D 8731. In contrast, contractions to angiotensin II were augmented by cyclosporin A, lisinopril, and the combination of both but not by D 8731 or D 8731 plus cyclosporin A. The data suggest a role for angiotensin II in cyclosporin A-induced endothelial dysfunction. Chronic ACE inhibition reduces overall smooth muscle contractility. The selective augmentation of angiotensin II effects by ACE inhibition and cyclosporin A suggests upregulation of angiotensin receptors in the aortic smooth muscle by these treatments. Chronic angiotensin subtype 1 receptor blockade does not appear to affect angiotensin receptor function.
Hypertension 1994 Jun
PMID:Vasomotor responses in cyclosporin A-treated rats after chronic angiotensin blockade. 820 13

Vasoconstriction and hypertension are major side effects of cyclosporine therapy. The mechanism or mechanisms responsible for the vascular effects of cyclosporine are unclear. The vascular effects of cyclosporine may arise as a consequence of endothelial dysfunction induced by the agent. To test this possibility, we compared in vessels prepared in myographs endothelium-mediated relaxations of mesenteric resistance arteries of Wistar-Kyoto rats treated for 21 to 28 days with subcutaneous injections of cyclosporine (25 mg/kg per day), or vehicle. Endothelium-dependent relaxations in response to acetylcholine were impaired in arteries from cyclosporine-treated rats; the concentrations of acetylcholine required to produce 50% relaxation of norepinephrine activation (pD2) were 31.6 +/- 0.1 versus 5 +/- 0.1 nmol/L in control arteries (P < .05). Nitro-L-arginine produced comparable 10-fold decreases in sensitivity to acetylcholine in arteries from both rat groups, indicating that the relaxations were mediated by endothelium-derived nitric oxide. Acetylcholine-induced relaxations in cyclosporine-treated arteries were normalized by pretreatment of the arteries with superoxide dismutase (150 IU/mL; pD2, 3.6 +/- 0.1; P < .05); superoxide dismutase had no effect on relaxations in control arteries. SQ 29,548, an inhibitor of prostaglandin H2/thromboxane A2 receptors; H-7, an inhibitor of protein kinase C; and indomethacin did not alter relaxations in response to acetylcholine in either group of arteries. Cyclosporine-treated arteries were more sensitive than control arteries to nitroprusside, an agent that induces relaxation via nitric oxide (pD2, 1.3 and 6.2 mumol/L, respectively; P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension 1994 Jun
PMID:Cyclosporine produces endothelial dysfunction by increased production of superoxide. 820 35

Cyclosporine induces hypertension and wide-spread vasoconstriction after transplantation in addition to reducing kidney function. We studied hemodynamic, renal, and hormonal effects of monotherapy with nifedipine XL (n = 37) in liver transplant recipients within a year after transplant (median, 4.4 months). Systemic hemodynamics were determined with thoracic electrical bioimpedance. Blood pressure before therapy was 172 +/- 4/108 +/- 2 mm Hg. Sixty-four percent of recipients achieved blood pressures less than 140/90 mm Hg mediated by a fall in systemic vascular resistance index (2427 +/- 245 dyne.s.cm-5.m-2 in responders versus 2905 +/- 281 in nonresponders, P < .01). Despite the fall in systemic vascular resistance, glomerular filtration rates were not changed during nifedipine therapy, as measured by both creatinine and iothalamate clearances. Urinary prostacyclin (6-ketoprostaglandin F1 alpha) was suppressed below normal from 2468 +/- 323 ng/d before transplant to 1103 +/- 99 ng/d (P < .01) after transplant and did not change during nifedipine therapy. Urinary thromboxane B2 and plasma renin activity also fell after transplant and remained low during nifedipine. These data demonstrate that nifedipine can reverse systemic vasoconstriction associated with hypertension after transplantation. Systemic effects were not transmitted to the kidney sufficiently to improve glomerular filtration rate or reverse hormonal changes within the kidney. Hence, vascular and functional regulation of the kidney was dissociated from the systemic circulation during nifedipine administration after transplantation.
Hypertension 1994 Jan
PMID:Systemic and renal effects of nifedipine in cyclosporine-associated hypertension. 828 63

Cyclosporin A has markedly improved graft survival in transplant patients but its side effects, such as renal toxicity and hypertension, pose management problems in transplant recipients. This toxicity has been attributed to prostaglandin inhibition. Concurrent administration of misoprostol (a prostaglandin E1 analog) prevents chronic cyclosporin A-induced nephrotoxicity but not hypertension in rats.
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PMID:The effect of prostaglandin E1 analog misoprostol on chronic cyclosporin nephrotoxicity. 830 54

Cyclosporine is a potent tool in the immunosuppressive armamentarium. It provides relatively selective inhibition of T-cell responses without dampening nonspecific resistance. However, its use is confounded by a pleiotropic array of side effects, the most important of which is renal dysfunction with the not uncommon sequelae of hypertension, hyperuricemia, and hyperkalemia. The hepatic injury associated with CyA administration, which is characterized by a chronic elevation of serum transaminase values, is potentiated by azathioprine or recrudescent or de novo viral infections. Finally, the proclivity of the drug to produce hyperlipidemia may jeopardize long-term survival; patients not infrequently require gemfibrizol and/or pravastatin therapy to control triglyceride and/or cholesterol levels, respectively. Two strategies appear to be useful. Our concentration-control strategy assesses CyA exposure by analyzing serial pharmacokinetic profiles, titering drug doses to achieve initial steady state concentrations of 400 ng/mL during continuous i.v. infusion, and to achieve average concentrations, namely AUC divided by dosing interval (in hours), of 550 ng/mL initially with trough levels of 200 ng/mL or above. Pretransplant pharmacokinetic profiling permits prediction of the appropriate initial i.v. dose in 73% of patients, and in combination with a posttransplant profile of the oral dose in about 60% of patients. The target oral concentrations are progressively reduced, thereby permitting prospective CyA control and minimizing adverse effects. The second synergistic drug strategy uses the median effect mathematical model to identify new drug combinations. The combination of CyA with RAPA, a macrolide which inhibits lymphokine signal transduction, and with BQR, a difluoro quinoline carboxylic acid analog that inhibits pyrimidine biosynthesis, permits at least a 20-fold reduction of the CyA dose in rat allograft models as well as prevents the activation of some CyA-resistant rejection pathways. Future investigations of pharmacologic strategies are undoubtedly likely to re-enforce the efficacy and safety of CyA administration for a range of immunologic disorders.
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PMID:Optimization of cyclosporine therapy. 835 18

Cyclosporine represents the foundation for current immunosuppressive therapy following solid organ transplantation. CsA use is associated with renal insufficiency and systemic hypertension. We hypothesized that CsA would enhance the vascular actions of endothelin (ET). Three groups of anesthesized dogs (n = 15) were studied. Group 1 received CsA alone (1 mg/kg), group 2 received ET alone (1 ng/kg/min), and group 3 received combined CsA (1 mg/kg) and ET (1 ng/kg/min). The hemodynamic and renal effects were evaluated after 30 min. Combined treatment resulted in a profound reduction in mean arterial pressure (-62 +/- 14 mmHg (P < .05) and cardiac output (-2.2 +/- 0.4.1/min (P < .05). The reduction in mean arterial pressure and cardiac output were significantly greater than that observed with CsA or ET alone. Systemic vascular resistance was not significantly changed. Combined CsA and ET resulted in a significant reduction in renal blood flow (195 +/- 18 to 101 +/- 11 ml/mm P < .05) but without evidence of active renal vasoconstriction. The decline in GFR (31.8 +/- 5.6 ml/min to being unmeasurable) was of greater magnitude than the change in renal blood flow, suggesting enhanced afferent anteriolar vasoconstriction or an alteration in the ultrafiltration coefficient. These studies demonstrate an important and synergistic cardiodepressor effect when CsA and ET are combined.
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PMID:The synergistic effects of cyclosporine and endothelin--demonstration of an important cardiodepressor action. 842 69

Bone marrow transplantation (BMT) using HLA-partially matched family donors has produced disappointing results (25-30% of long-term survivors) in patients with severe aplastic anemia. We describe two children affected by severe aplastic anemia, not responsive to immunosuppressive therapy, who underwent allogeneic bone marrow transplantation using a HLA-partially matched family donor. Both cases presented 2 first class HLA-antigens (A and B) disparity between donor and recipient. The pretransplant conditioning regimen consisted of cyclophosphamide, thoracoabdominal irradiation, cytosine-arabinoside, and antilymphocyte globulin. As graft versus host disease (GVHD) prophylaxis, Cyclosporine-A was administered at usual dosages for 6 months. A full marrow engraftment was observed in both cases. Only grade I acute GVHD, promptly responsive to corticosteroid therapy, developed with no chronic GVHD. Five months after transplant, both children progressively developed hypertension, renal function impairment, thrombocytopenia, and severe normochromic anemia, with erythropoietin serum levels lower than expected for the haematocrit. After antihypertension treatment and supportive therapy, the clinical picture progressively improved, while treatment with recombinant human erythropoietin completely corrected the long-lasting anemia. The two children are alive and well 28 months after the transplant, with a Karnofsky score of 100% and a normal peripheral blood count. The authors suggest that, once immunosuppressive therapy has failed, BMT from donors other than HLA-identical sibling is a feasible approach in children affected by severe aplastic anemia, not having an HLA-identical donor.
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PMID:Successful bone marrow transplantation in children with severe aplastic anemia using HLA-partially matched family donors. 843 7

Cyclosporine and in particular oxidatively modified low density lipoproteins can both exert direct vasoconstricting effects. We hypothesized that coincubation of arteries with low density lipoproteins and cyclosporine would enhance their respective influence on vascular tone. Therefore, we investigated vascular reactivity of isolated intact rabbit renal arteries preincubated with cyclosporine in the presence of native and oxidized low density lipoproteins. After preincubation of the arteries with cyclosporine (10 micrograms/ml, 90 minutes), unstimulated vascular tone as well as norepinephrine-induced vasoconstrictions remained unchanged compared with controls preincubated with the cyclosporine solvent dimethyl sulfoxide. Oxidized low density lipoproteins (100 micrograms/ml) in the absence of cyclosporine significantly enhanced vasoconstrictions to threshold concentrations of norepinephrine (78 +/- 10 microns at 30 nM). However, after cyclosporine treatment, the oxidized low density lipoprotein-induced potentiation of contractile responses to norepinephrine was further enhanced (157 +/- 19 versus 71 +/- 11 microns). Native low density lipoproteins had no influence on vascular tone. Potentiation of norepinephrine-induced vasoconstriction by oxidized low density lipoproteins took place in either endothelium-denuded or endothelium-intact arteries, whereas the further enhancement of vascular tone after cyclosporine treatment was seen only in endothelium-intact segments. Endothelium-dependent dilations to acetylcholine were fully preserved after treatment with oxidized low density lipoproteins and cyclosporine. Indomethacin, saralasin, and the thromboxane A2 antagonist daltroban had no influence, but the Ca2+ antagonist verapamil prevented the potentiation of vasoconstrictions by cyclosporine and oxidized low density lipoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension 1993 Mar
PMID:Cyclosporine and oxidized lipoproteins affect vascular reactivity. Influence of the endothelium. 847 41


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