Lovastatin protects mithochondrial and renal function in kidney ischemia-reperfusion in rats / Lovastatina protege a função renal e mitocondrial na isquemia/reperfusão renal em ratos

PURPOSE: To investigate the effect of lovastatin on renal ischemia followed by reperfusion. METHODS: Thirty one Wistar rats submitted to left renal ischemia for 60 minutes followed by contralateral nephrectomy were divided into two groups: A (n =17, control, no treatment), and B (n=14, lovastatin 15 mg/kg/day p.o. ten days before ischemia). The animals were sacrificed at the end of ischemia, after 24 hours and at seven days after reperfusion. Survival, serum urea and creatinine levels and renal mitochondrial function were evaluated. RESULTS: Mortality was 29.4% in group A and 0.7% in group B. Urea and creatinine levels were increased in both groups, but the values were significantly lower in group B. Mitochondrial function showed decoupling in 83.4% of group A, as opposed to 38.4/% of group B. CONCLUSIONS: The result shows a protective action of renal function by lovastatin administered before ischemia/reperfusion. Since most of the mitochondrial fraction presented membranes with the ability to maintain ATP production in group B, stabilization of the mitochondrial membrane should be considered as part of the protective action of lovastatin on renal function in ischemia/reperfusion.

OBJETIVO: Investigar a ação da lovastatina na isquemia renal seguida de reperfusão. MÉTODOS: Trinta e um ratos Wistar submetidos à isquemia renal esquerda durante 60 minutos, seguida da nefrectomia contralateral, foram distribuídos em dois grupos: A (n=17, controle, sem tratamento) e B (n=14, recebendo 15 mg/Kg/dia de lovastatina via oral), durante os dez dias que antecederam a isquemia. Os animais foram mortos ao final da isquemia, e com 24 horas e sete dias após a reperfusão. Foram avaliadas a sobrevida, os valores séricos de uréia e creatinina e a função mitocondrial renal. RESULTADOS: A mortalidade foi 29,4% no grupo A e 0,7% no grupo B. Os níveis de uréia e creatinina elevaram-se nos dois grupos, mas foram significativamente menores no grupo B. No grupo A a função mitocondrial renal ficou desacoplada em 83,4% dos ensaios, enquanto que no grupo B isto ocorreu em apenas 38,4% dos ensaios. CONCLUSÕES: Os resultados mostram que a administração de lovastatina antes do episódio de isquemia protege a função renal. No grupo B, como a maior parte da fração mitocondrial isolada apresentou função acoplada à produção de ATP, deve-se também considerar a estabilização da membrana mitocondrial como parte da ação protetora da lovastatina na função renal durante isquemia e reperfusão.

Efectos pleiotrópicos de las estatinas: [revisión] / Pleiotropic effects of statins: [review]

Results of numerous epidemiologic studies indicate that elevated serum cholesterol, especially the LDL fraction, is a major cause of coronary heart disease (CHD). Epidemiologic and angiographic evidence from primary and secondary prevention studies involving several HMG-CoA reducíase inhibitors (statins) indicate that decreasing elevated serum cholesterol concentration (specifically LDL-cholesterol) can reduce the incidence of CHD and/or progression of atherosclerosis and results in a decrease in associated morbidity and mortality. It has been estimated that each 1 percent reduction in LDL-cholesterol concentration may result in a 1 percent decrease in the incidence of CHD. Furthermore, an analysis of pooled data from primary and secondary prevention studies found that treatment with a statin for a median duration of 5.4 years was associated with a 31 percent and 21 percent reduction in the risk of major coronary events and total mortality, respectively. This paper deals with the pharmacology of statins, specially with the pleiotropic effects ofthese drugs.

[ effect of hydroalcoholic extracts of Hypericum perforatum and Amaranthus caudatus on rabbits with hypercholesterolemia]

Atherosclerosis is one of the most common causes of death throughout the world. In this study, anti-atherosclerotic effect of combination extracts of Hypericum and Amaranth on hypercholesterolemic rabbits was compared with that of lovastatin. Twenty adult male Newzeland rabbits were randomly divided into four groups of five and were fed for 60 days as follows: basic diet, high cholesterol, high cholesterol along with combination Hypericum and Amaranth [HA] extract [75 mg/kg] and high cholesterol along with lovastatin [10 mg/kg]. Blood samples were taken at the beginning, one month later and at the end of the study in order to measure their serum factors. Data were analyzed using ANOVA and Danken tests. The extract and lovastatin decreased the levels malondialdehyde [MDA] and apolipoprotein B [apoB], apoB/apoA and increased the levels apolipoprotein A [apoA] in rabbits compared to high cholesterol group [P<0.05]. The extract by decreasing cardiovascular risk factors especially apoB that is one of the most important risk factors of cardiovascular diseases, prevent progression of atherosclerosis. The extract is more effective in decreasing the level of cardiovascular risk factors than Lovastatin in hypercholesterolemic rabbits

Hipotiroidismo y miopatia por atorvastatina: reporte de un caso / Hypothyroidism and myopathy by atorvastatin: report of a case

Se presenta un caso de un hombre de 56 años con dislipidemia e hipotiroidismo, quien desarrolló una miopatía inflamatoria asociada al uso de atorvastatina. Siete meses después de iniciado el tratamiento el paciente presentó debilidad e hipotrofia muscular progresiva, dolor tarácico y elevación sérica de los niveles de creatinquinasa total. El cuadro clínico revirtió en su totalidad después de suspender el tratamiento con lovastatina. Se revisa la literatura más reciente sobre estatinas y miopatía y se presenta su diagnóstico diferencial.

[Assessment of osteoinduction by statins in rat]

To date, studies about the systemic effects of statins on bone tissue have led to different resuts. The aim of this study was to assess the osteoinductivity by statins when injected intramuscularly or subcutaneously in rats. In this experimental study, 68 injections of Simvastatin, Lovastatin, Atorvastatin in polyethyleneglycole with 1mg/ml and polyethyleneglycole 300 were injected either S.C in rat`s backs or I.M into their hand and foot. After 6 weeks, the rats were killed and samples of the injection areas were provided and were studied under a microscope. In two of the samples, few bony areas were seen which were a mixture of lamellar and woven bone. Around these areas' an osteoblastic rim was visible. In another sample, a chondral area with an active mesanchimal connective tissue which was in a differentiation state to become cartilage, was seen. Finding of this study and the gradual differentiation of muscular tissue to bony stem tissue in around samples, confirms the probable osteoinductivity effect of theses compound. To confirm further we propose that this effect should be investigated on stem cell cultures, in vitro

Lovastatin reduces neuronal cell death in hippocampal CA1 subfield after pilocarpine-induced status epilepticus: preliminary results

OBJETIVO: Capacidade da lovastatina em prevenir a perda de neurônios hipocampais após o status epilepticus (SE) induzido pela pilocarpina. MÉTODO: Ratos adultos Wistar foram divididos em 4 grupos: (A) ratos controles que não receberam pilocarpina nem lovastatina (n=5); (B) ratos controles que receberam somente lovastatina (n=5); (C) ratos que receberam somente pilocarpina (n=5); (D) ratos que receberam pilocarpina e lovastatina (n=5). Após a administração de pilocarpina (350mg/kg, i.p.), somente ratos que evoluíram para o status epilepticus foram incluídos em nosso estudo. A atividade epiléptica foi interrompida com uma injeção de diazepam (10 mg/kg, i.p.) após 4h do início do SE. Os ratos tratados com lovastatina receberam duas doses de 20mg/kg via esofágica, imediatamente e 24 h após a indução do SE. Sete dias após o SE induzido pela pilocarpina, todos os animais foram perfundidos e seus cérebros processados para análise histológica através do método de Nissl. RESULTADOS: A contagem celular da formação hipocampal mostrou uma significante perda celular nos animais que receberam pilocarpina e apresentaram SE (CA1= 26,8 ± 13,67; CA3= 38,1 ± 7,2; hilus= 43,8 ± 3,95) quando comparados com animais pertencentes ao grupo controle (Grupo A: CA1= 53,2 ± 9,63; CA3= 63,5 ± 13,35; hilus= 59,08 ± 10,24; Grupo B: CA1= 74,3 ± 8,16; CA3= 70,1 ± 3,83; hilus= 70,6 ± 5,10). O número de células neuronais na região CA1 do hipocampo de ratos que apresentaram SE e receberam lovastatina (44,4 ± 17,88) foi estatisticamente maior quando comparado com animais que somente apresentaram SE. CONCLUSÃO: A lovastatina exerce papel neuroprotetor na atenuação do dano cerebral após o SE.

Statin inhibits interferon-gamma-induced expression of intercellular adhesion molecule-1 (ICAM-1) in vascular endothelial and smooth muscle cells

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, known as statins, are widely used for primary and secondary prevention of coronary artery atherosclerosis. Pathogenesis of atherosclerosis is multistep processes where transendothelial migration of various leukocytes including monocytes is a crucial step. Interferon-gamma(IFN-gamma) contributes in this process by activating macrophages and T-lymphocytes, and by inducing adhesion molecules in vascular endothelial and smooth muscle cells. In this study we investigated the expression of intercellular cell adhesion molecule- 1 (ICAM-1) in transformed endothelial cell line ECV304 cells as influenced by lovastatin, tumor necrosis factor-alpha (TNF-alpha) and IFN-gamma. Results show that lovastatin suppresses expression of ICAM-1 by inhibiting the IFN-gamma-induced extracellular signal-regulated kinase (ERK) p44/p42-STAT1 signaling pathway. In cells treated with lovastatin and IFN-gamma.ICAM-1 was expressed at a lower level than in cells treated with IFN-gamma alone. However, lovastatin does not reduce TNF-alpha induced expression of ICAM-1. A similar result was observed in cells treated with the MEKK inhibitor PD98059 and IFN-gamma. Cis-acting DNA sequence elements were identified in the 5'-flanking region of the ICAM-1 promoter that mediate inhibition by lovastatin; these sequences map to the IFN-gamma activated site which also binds the STAT1 homodimer. However, lovastatin did not inhibit IFN-gamma-mediated induction of the Y701 phosphorylated form of STAT1. But lovastatin does inhibit the IFN-gamma-mediated phosphorylation of ERK1/ERK2 (T202/Y204) and S727 phosphorylation of STAT1. TNF-alpha does not induce phosphorylation of ERK1/ERK2 and S727 in ECV304 and smooth muscle cells. The results provide the evidences that statins may have beneficial effects by inhibiting IFN-gamma action in atherosclerotic process

Efecto comparativo de policosanol con dos inhibidores de la HMG-CoA reductasa en el tratamiento de la hipercolesterolemia tipo II / Comparative effects of policosanol and two HMG-CoA reductase inhibitors on type II hypercholesterolemia

Background: Policosanol is a new cholesterol lowering agent derived from sugar cane. Aim: To compare the cholesterol lowering efficacy of policosanol with HMG CoA inhibitors. Patients and methods: Patients with a LDL cholesterol over 160 mg/dl were studied. If, after 6 weeks of diet, cholesterol persisted elevated, they were doubly blind randomized to receive policosanol 10 mg/day (55 patients), lovastatin 20 mg/day (26 patients) or simvastatin 10 mg/day (25 patients). Serum cholesterol was measured again after 8 weeks of therapy. Results: Initial demographic and laboratory data were similar among treatment groups. A 24 percent LDL cholesterol reduction was obtained with policosanol, compared with a 22 percent reduction with lovastatin and a 15 percent reduction with simvastatin. HDL cholesterol significantly increased in patients on policosanol and did not change in the other treatment groups. Adverse effects of policosanol were mild and unspecific. No changes in hepatic enzymes were observed. Conclusions: Policosanol is a safe and effective cholesterol reducing agent

The effect of lovastatin on proliferation of cultured rat mesangial and aortic smooth muscle cells

In order to investigate the anti-proliferative effect of 3-hydroxy-3-methylglutaryl coenzyme. A reductase inhibitor, we evaluated the effects of lovastatin on DNA replication and the proliferation of rat mesangial and aortic smooth muscle cells, both of which were mesenchymal origin cells. Proliferations were determined by measuring [3H]thymidine uptake, and counting the number of cells. Growth-arrested mesangial and aortic smooth muscle cells were exposed to platelet-derived growth factor (PDGF), endothelin (ET) and angiotensin II (Ang II) to stimulate mitogenesis. All agents exhibited dose-dependent stimulation of [3H] thymidine uptake. PDGF was more potent than the others. Ang II increased [3H] thymidine uptake without demonstrable mitogenic activity. Lovastatin inhibited PDGF (10 ng/ml in mesangial cell, 25 ng/ml in smooth muscle cell)-, ET (10(-7)M)- and Ang II (10(-7)M)-induced [3H] thymidine uptake significantly in a dose-dependent manner in both cells. The increase of cell number in response to PDGF and ET treatment were also inhibited at 10 microM of lovastatin. The inhibitory effect of lovastatin was largely overcome in the presence of exogenous mevalonate at 200 microM, with 75.5% restoration from lovastatin-induced inhibition on PDGF-induced [3H] thymidine uptake in mesangial cells (77.8% in aortic smooth muscle cells). However, the addition of cholesterol did not prevent inhibition by lovastatin. In conclusion, lovastatin had an inhibitory effect on mesangial and aortic smooth muscle cell proliferation, and mevalonate was essential for DNA replication in both types of cells. Lovastatin may reduce glomerular and atherosclerotic injury through an anti-proliferative effect on mesangial and vascular smooth muscle cells, in addition to lowering circulating lipids.

Estatinas no tratamento da hipercolesterolemia / Statins in the hypercholesterolemia treatment

Estatinas säo drogas derivadas de microorganismos e que eficientemente interferem na síntese celular de colesterol por inibiçäo competitiva da enzima HMG-CoA-redutase. Näo obstante, as estatinas reduzem a colesterolemia por induzirem formaçäo de receptores que captam as LDL do plasma e por diminuirem a síntese de VLDL no fígado. Esta última explica o efeito parcial na queda da trigliceridemia. A eficiência das estatinas na diminuiçäo da colesterolemia é comparável à das resinas seqüestradoras de ácidos biliares, porém superios à dos fibrates e ácido nicotínico. Estatinas säo melhor toleradas do que estas últimas duas drogas, mas inferiores quanto à capacidade de diminuirem os triglicérides e de aumentarem o HDL-colesterol. Seletividade tissular varia entre as diversas estatinas, mas esta é uma questäo irrelevante tendo em vista a raridade dos efeitos colaterais. Conseqüentemente, estas drogas devem ser prescritas em razäo da potência farmacológica e do fator custo. Cinecoronarioangiografia seqüencial em pacientes com coronariopatia tratados com placebo em comparaçäo a estatinas isoladamente, indica que a doença arterial regride por métodos farmacológicos.