The pulmonary effects of buthionine sulfoximine treatment and glutathione depletion in rats

Buthionine sulfoximine (BSO), an inhibitor of de novo synthesis of glutathione (GSH), was used to deplete rats of GSH and determine the effect of treatment on antioxidant enzyme responses, lung injury, and the susceptibility to concurrent sublethal or lethal hyperoxia. In a preliminary experiment, total lung nonprotein sulfhydryl (NPSH) and GSH levels were measured at various times after single doses of BSO. The lowest concentrations were observed at 12 to 18 h. These experiments were used to establish a repeated dosing protocol for more prolonged GSH depletion. The lungs of rats treated with BSO for 4 days demonstrated markedly decreased GSH and NPSH levels (10 to 40% of control values) and glutathione peroxidase activity (45 to 60% of control values). Superoxide dismutase activities were elevated, glutathione reductase activity was slightly elevated, and catalase activity was unchanged. These changes were dose-responsive. The lungs of treated rats were grossly and microscopically normal. BSO treatment of additional rats did not increase susceptibility to lethal hyperoxia (greater than 98% oxygen). Combined treatment of rats with both BSO and sublethal hyperoxia (80% oxygen) for 4 days did not alter the biochemical responses demonstrated by rats treated solely with BSO. The marked increase in catalase activity obtained after hyperoxia alone was not observed in rats treated with both hyperoxia and BSO. The lungs of saline- and BSO-treated rats exposed to sublethal hyperoxia demonstrated a patchy distribution of slight perivascular and peribronchiolar edema.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improved use of buthionine sulfoximine to prevent cisplatin nephrotoxicity in rats

Summary Male Sprague Dawley rats were treated with buthionine sulfoximine (BSO) and cisplatin in different doses and schedules to optimize the chemoprotective effect of BSO against cisplatin nephrotoxicity. BSO at 4 mmol/kg, administered s.c. 2 h prior to cisplatin, resulted in normal blood urea nitrogen (BUN) levels in rats treated with 3 or 4 mg/kg cisplatin, and modestly, but significantly reduced the toxicity of cisplatin at 5 mg/kg. Administration of BSO (4 mmol/kg) at intervals ranging from 0 to 16 h prior to cisplatin (5 mg/kg) resulted in a significant reduction in BUN values. A BSO dose as low as 0.04 mmol/kg was found to be as effective as 4 mmol/kg against nephrotoxicity associated with cisplatin at 4 mg/kg. Repetitive injections of BSO (1 mmol/kg every 12 h, four times, beginning 2 h prior to cisplatin) significantly inhibited elevations of BUN associated with high-dose cisplatin (6 mg/kg), whereas a single BSO injection of 4 mmol/kg was ineffective. The degree and duration of renal glutathione depletion was related to the dose of BSO. Renal glutathione content following 4 mmol/kg BSO was 38% of control at 2 h and 40% at 24 h; following 0.04 mg/kg, glutathione was 47% at 2 h and almost 100% at 24 h. Simultaneous in vitro administration of BSO did not inactivate cisplatin cytotoxicity as measured by the colony-forming ability of MBT-2 cells in soft agar. These data indicate that repeated injections of BSO, beginning prior to cisplatin administration, would improve the nephroprotective effect without compromising the chemotherapeutic efficacy of cisplatin. It is suggested that the ability of BSO to reduce cisplatin nephrotoxicity may not correlate with the degree of renal glutathione depletion and that the mechanism of action is unlikely to involve direct inactivation of cisplatin.Abbreviations BSO -buthionine sulfoximine - BUN blood urea nitrogen     

丁硫氨酸硫酸亚胺逆转人结肠癌细胞多药耐药的机制

目的探讨丁硫氨酸硫酸亚胺(BSO)逆转人结肠癌LoVo／Adr细胞多药耐药性的可行性,并初步探讨其逆转机制。方法MTT法检测BSO对多药耐药LoVo／Adr细胞抗癌药物敏感性的影响; RT-PCR法检测细胞中多药耐药1(mdr1)基因及谷胱甘肽巯基转移酶(GST)-πmRNA水平;免疫组化染色检测GST-π蛋白水平;1氯-2,4-二硝基苯法测定GST活性。结果BSO作用后亲本LoVo细胞中阿霉素、丝裂霉素的IC50无显著变化,而在LoVo／Adr细胞中,阿霉素的IC50由(3．08±0．84)mg／L降至(1.31±0．53)mg／L(t=3．09,P<0．05),丝裂霉素的IC50由(1．24±0．45)mg／L降至(0．54±0．32)mg/L(t=165．50,P<0.01);BSO对mdr1基因mRNA水平无影响,BSO作用前后GST-πmRNA表达量分别为1．75±0.24和0．84±0．19(t=5．11,P<0．05),BSO作用后LoVo／Adr细胞GST-π蛋白表达显著低于处理前;BSO处理前后LoVo／Adr细胞GST活性分别为(144．26±50．13)和(129.58±41．36)U／mg(t=0,57,P>0．05)。结论BSO可有效增强人结肠癌耐药细胞LoVo／Adr对阿霉素、丝裂霉素的敏感性,具有逆转作用,其机制与mdr1基因无关,但与GST-π基因下调有关,可能是通过降低细胞内GST-π含量,增强对化疗药物的敏感性。     

Preclinical evaluation of azathioprine plus buthionine sulfoximine in the treatment of human hepatocarcinoma and colon carcinoma

AIM: To evaluate the efficacy and the safety of azathioprine (AZA) and buthionine sulfoximine (BSO) bylocalized application into HepG2 tumor in vivo.METHODS: Different hepatoma and colon carcinoma cell lines (HepG2, HuH7, Chang liver, LoVo, RKO, SW-48, SW-480) were grown in minimal essencial medium supplemented with 10% fetal bovine serum and 1% antibiotic/antimycotic solution and maintained in a humidified 37 ℃ incubator with 5% CO2. These cells were pretreated with BSO for 24 h and then with AZA for diffe...     

Cataractogenesis and lipid peroxidation in newborn rats treated with buthionine sulfoximine: Preventive actions of melatonin

ABSTRACT: The purpose of this study was to examine the influence of exogenously administered melatonin on cataract formation and lipid peroxidation in newborn rats treated with buthionine sulfoximine (BSO), a drug which inhibits the rate-limiting enzyme in glutathione (GSH) synthesis, y-glutamylcysteine synthase, thereby depleting animals of their stores of the important intracellular antioxidant, GSH. BSO (3 mmol/kg BW) was given for three consecutive days beginning on postnatal day 2; melatonin (4 mg/kg) was injected daily beginning on postnatal day 2 and continuing until the animals were killed (either day 9 or day 17 after birth). None of the control animals (rats treated with neither BSO nor with melatonin) developed lenticular opacification during the observation period. In the BSO-treated rats, 16 of 18 animals (89%) had observable cataracts when they were examined. In rats that received both BSO and melatonin, the incidence of cataracts was highly significantly decreased, i.e., only 3 of 18 rats (7%) had observable cataracts. In addition to cataracts, the level of lipid peroxidation products (malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA)) was examined in the lens, brain, liver, lung, and kidney of control and experimental animals. In BSO-treated rats, the lens, kidney, and lung exhibited increased levels of MDA plus 4-HDA relative to those measured in the control rats; these increases were reversed in the BSO-treated rats who were injected with melatonin daily. While BSO administration did not increase basal levels of MDA plus 4-HDA in either the brain or liver, melatonin reduced levels of lipid peroxidation products below those measured in the control rats (at 17 days after birth). The changes induced by melatonin are consistent with the free-radical scavenging and antioxidative properties of this indole.     

Cardiovascular manifestations of Alkaptonuria

The cardiovascular manifestations of alkaptonuria relate to deposition of ochronotic pigment within heart valves, endocardium, aortic intima and coronary arteries. We assessed 16 individuals with alkaptonuria for cardiovascular disease, including full electrocardiographic and echocardiographic assessment. The self reported prevalence of valvular heart disease and coronary artery disease was low. There was a significant burden of previously undiagnosed aortic valve disease, reaching a prevalence of over 40% by the fifth decade of life. The aortic valve disease was found to increase in both prevalence and severity with advancing age. In contrast to previous reports, we did not find a significant burden of mitral valve disease or coronary artery disease. These findings are important for the clinical follow-up of patients with alkaptonuria and suggest a role for echocardiographic surveillance of patients above 40 years old.     

Cardiovascular manifestations of phaeochromocytoma

Clinical expression of phaeochromocytoma may involve numerous cardiovascular manifestations, but usually presents as sustained or paroxysmal hypertension associated with other signs and symptoms of catecholamine excess. Most of the life-threatening cardiovascular manifestations of phaeochromocytoma, such as hypertensive emergencies, result from a rapid and massive release of catecholamines from the tumour. More rarely, patients with phaeochromocytoma present with low blood pressure or even shock that may then precede multisystem crisis. Sinus tachycardia, with palpitations as the presenting symptom, is the most prevalent abnormality of cardiac rhythm in phaeochromocytoma, but tumours can also be associated with more serious ventricular arrhythmias or conduction disturbances. Reversible dilated or hypertrophic cardiomyopathy are well established cardiac manifestations of phaeochromocytoma, with more recent attention to an increasing number of cases with Takotsubo cardiomyopathy. This review provides an update on the cause, clinical presentation and treatment of the cardiovascular manifestations of phaeochromocytoma. As the cardiovascular complications of phaeochromocytoma can be life-threatening, all patients who present with manifestations that even remotely suggest excessive catecholamine secretion should be screened for the disease.     

嗜铬细胞瘤的心血管表现

<正>嗜铬细胞瘤和副神经节瘤(pheochromocytoma and paraganglioma,PH/PGL)是起源于胚胎神经嵴的副神经节细胞的少见神经内分泌肿瘤。位于肾上腺的称为PH,位于肾上腺外的称为PGL。绝大多数PH/PGL产生儿茶酚胺,且多数患者以分泌去甲肾上腺素为主,合并分泌肾上腺素,并因     

Oxidative stress by glutathione depletion induces osteonecrosis in rats

OBJECTIVE: We recently implicated in vivo oxidative stress in the development of osteonecrosis in a steroid-induced osteonecrosis model in the domestic rabbit. In the present experiment we devised a new non-traumatic model using the rat to investigate the relationship between oxidative stress and the development of osteonecrosis. METHODS: Seven 24-week-old male Wistar rats were subcutaneously injected with the pro-oxidant buthionine sulphoximine (BSO) 500 mg/kg for 14 consecutive days (group B) and eight rats received injections of vehicle (physiological saline; group N). The rats in both groups were killed after 14 days, and their bilateral femurs were examined histopathologically. Blood levels of reduced glutathione (GSH), total cholesterol (T-cho) and triglycerides (TG) were also determined. RESULTS: GSH was significantly decreased in group B compared with group N (P < 0.01). No significant differences were found in T-cho or TG. Osteonecrosis was not detected in any animal in group N in contrast to five of seven animals in group B (P < 0.05). CONCLUSION: BSO is an inducer of oxidative stress, in particular interfering with the synthesis of GSH in vivo. In the present study, GSH levels were markedly reduced by BSO, whereas neither T-cho nor TG was significantly changed. The high rate of osteonecrosis noted in group B suggests that oxidative stress alone may be sufficient to promote the development of osteonecrosis at certain sites.     

甲状旁腺功能减退症和假性甲状旁腺功能减退症心血管系统表现

甲状旁腺功能减退症(hypoparathyroidism,HP)和假性甲状旁腺功能减退症(pseudohypoparathyroidism,PHP)均以低钙血症、高磷血症为主要生化特征,前者甲状旁腺素(parathyroid hormone,PTH)减低或不适当的正常,后者PTH水平升高,这些生化指标异常均可能对心血管系统产生不利影响。急性严重低钙血症在HP和PHP患者会造成心脏结构和功能异常,急性和慢性低钙血症还会引起心脏传导异常。研究发现HP患者动脉粥样硬化和冠状动脉钙化的风险增加;而PHP患者可能出现高血压、肥胖和糖代谢异常。已有单中心研究发现非术后HP患者死亡和心血管事件发生风险增加。因目前研究数量有限,尚需进一步研究以探索HP和PHP对心血管系统的影响及其机制和可能风险。     

还原型谷胱甘肽对单侧输尿管梗阻致肾间质纤维化的保护作用

目的采用单侧输尿管梗阻（UUO）致肾间质纤维化大鼠模型,观察还原型谷胱甘肽（GSH）对转化生长因子β激活激酶（TAK1）表达的影响及对肾间质纤维化的保护作用。方法将72只大鼠随机分为假手术组、UUO模型组和GSH治疗组（GSH组）3组,每组24只。GSH组于术前1天给予还原型谷胱甘肽每天200mg／kg,腹腔注射。假手术组与UUO模型组给予等量生理盐水腹腔注射。HE及Masson染色观察梗阻侧肾脏病理变化,原位杂交及实时荧光定量PCR（RT—PCR）检测肾组织TAK1 mRNA的表达,Western—bloting检测TAK1及α-平滑肌肌动蛋白（α—SMA）的表达。结果与假手术组比较,UUO模型组TAK1及α—SMA的表达在UUO术后7天显著增加（P〈0．05）,但UUO模型组显著高于GSH组（P〈0．05）。结论GSH可能通过下调TAK1及α-SMA的表达,从而减轻UUO致肾间质纤维化的进展。     

Protection from glutathione depletion by a glyconutritional mixture of saccharides

A complex glyconutritional (GN) mixture of mono-, di-and polysaccharides was investigated to assess its capacity to protect two different types of rodent cells, rat hepatocytes and mouse splenocytes, from depletion of glutathione by a sulfhydryl-reactive mycotoxin, patulin, or by coxsackievirus B3 (CVB3) infection, respectively. Rat hepatocytes were treated with the GN mixture in vitro or received carrier medium only prior to treatment with patulin. When treated with the GN mixture prior to patulin exposure hepatocytes demonstrated protection against depletion of intracellular reduced glutathione (GSH). Cells treated with the GN for up to 15 hours prior to patulin exposure showed no increase in protection of GSH above that demonstrated by cells treated for 3 hours. Mice were infected with CVB3 and one treatment group was injected intraperitoneally with the GN once a week. Animals were splenectomized each month over a ten month treatment for analysis of spleen monocytic cells. Splenocytes from mice treated with the GN mixture did not show the virally-associated depletion of intracellular GSH or damage to pancreatic acini observed in CVB3 inoculated but non-GN-treated mice. Animals from which spleen cells were taken for analysis showed no decrease in anti-CVB3 antibodies and no decrease in viral titers to accompany or explain the normal levels of intracellular GSH. These data strongly suggest that a complex mixture of exogenous saccharides exerts a protective effect on liver cells in vitro in that the cells are protected from chemically initiated depletion of intracellular GSH, and on spleen cells in vivo in that the cells are protected against a CVB3-initiated decrease in intracellular GSH and increase in pancreatic acini damage.     

Cardiovascular manifestations of myotonic dystrophy

Patients with myotonic dystrophy, the most common neuromuscular dystrophy in adults, have a high prevalence of arrhythmic complications with increased cardiovascular mortality and high risk for sudden death. Sudden death prevention is central and relies on annual follow-up and prophylactic permanent pacing in patients with conduction defects on electrocardiogram and/or infrahisian blocks on electrophysiological study. Implantable cardiac defibrillator therapy may be indicated in patients with ventricular tachyarrhythmia.     

Cardiovascular manifestations of systemic elastorrhexis

INTRODUCTION: Systemic elastorrhexis or Gr?nblad-Strandberg-Touraine syndrome is a rare inherited disease characterized by a generalized elastic tissue dysplasia and polymorphic clinical features, with the main tissues affected being cutaneous, ocular and arterial. CURRENT KNOWLEDGE AND KEY POINTS: Usual cardiovascular complications of this entity include ischemic heart disease, renovascular hypertension and atherosclerotic peripheral vascular disease. Some cases of restrictive cardiomyopathies and valvular disease have been reported. Coronary artery disease, often with early onset, is seen in approximately 20% of cases. FUTURE PROSPECTS AND PROJECTS: This review of the literature concerning a rare cause of cardiopathy underlines the need to search for underlying elastorrhexis in the clinical setting of early onset and severe coronary artery disease or arteriopathy, especially in the absence of vascular risk factors. This hereditary disease has been traced to chromosome 16p13.1 and may in the future be easily diagnosed, bypassing the need for cutaneous biopsy.     

Cardiovascular manifestations of Lyme disease

Although the cardiac manifestations of Lyme disease may be diverse, in general they are treatable with currently available therapies. A high index of suspicion is required to make a diagnosis, especially for patients who may lack a suggestive history of tick exposure or residence in an endemic region. Lyme disease-related heart block may require pacemaker insertion and supportive care. The efficacy of antibiotics in the therapy of acute and chronic cardiac Lyme disease will require further study. Serologic testing and cardiac histopathology are the most precise methods of diagnosis. There is a need to develop more sensitive and specific diagnostic tests for Lyme disease and for Lyme carditis in particular.     

Cardiovascular manifestations of ankylosing spondylitis

Summary In a retrospective study, 40 patients with ankylosing spondylitis were assessed for extraspinal manifestations. Cardiovascular complications were found in 17 patients (42.5%)∶5(12.5%) had aortic insufficiency, 3 (7.5%) had atrioventricular block and 5 (12.5%) had bundle branch block. Wolff-Parkinson-White syndrome was diagnosed in one case and short PR syndrome in another. Cardiovascular complications were more common in patients with longer disease duration. Ischemic heart disease was found in 17.5% of the cases and pulmonary fibrosis in 15%. Peripheral arthritis was found in 42.5% and its prevalence did not differ in patients with or without cardiac involvement.