In vitro testing of flash-frozen sublingual membranes for storage and reproducible permeability studies of macromolecular drugs from solution or nanofiber mats.

Sublingual drug delivery allows systemic delivery of drug without difficulties connected with the gastrointestinal pathway. We developed a new simple protocol for easy-to-use processing and storage of porcine sublingual mucosal membrane for in vitro studies using "flash freezing" in liquid nitrogen. All the dextrans used as mucosal membrane integrity and permeability markers permeated only slowly through sublingual mucosa illustrating usability both the "fresh" and "flash frozen" sublingual membranes whereas conventional cold storage "frozen" membranes have shown significantly higher permeabilities for macromolecules due to the sustained damage. The permeability values were too low to expect dextrans to be potential carriers at this context. To test albumin as a drug carrier we compared FITC-albumin permeation from solutions vs. nanofiber mats donors. To increase the amounts and prolong the transport, we manufactured nanofiber mats loaded with fluorescently marked albumin using well-scalable electrospinning technology. Nanofiber mats have allowed albumin passage through the sublingual membrane in similar amounts as from the pure artificial saliva solution. Since salivary washout strictly limits the duration of liquid dosages, nanofiber mats may thus permit prolonged sublingual administration.

Intravenous rutin in rat exacerbates isoprenaline-induced cardiotoxicity likely due to intracellular oxidative stress.

OBJECTIVES: Rutin, quercetin-3-O-rutinoside, a natural flavonol glycoside, has shown various in vitro benefits with potential use treating human diseases, especially cardiovascular system disorders. Antioxidant properties are assumed to underlie the majority of these benefits. Yet rutin pro-oxidant properties have been reported as well. Our research group has recently shown aggravating effects on isoprenaline (ISO)-induced cardiotoxicity in Wistar:Han rats after 24 hours. METHODS: This study was designed to examine in more detail the reasons for the negative effects of rutin (11.5 and 46 mg/kg, i.v.) after administration of ISO (100 mg/kg, s.c.) in rats within 2 hours of continuous experiment and in the H9c2 cardiomyoblast-derived cell line. RESULTS: Like our previous findings, rutin did not (11.5 or 46 mg/kg, i.v.) reduce the ISO-induced mortality within 2 hours although the lower dose significantly reduced cardiac troponin T (cTnT) and partly improved the histological findings. In contrast, the higher dose increased the mortality in comparison with solvent (1.26% w/v sodium bicarbonate). This was not caused by any specific haemodynamic disturbances. It appears to be associated with oxidative stress as rutin enhanced intracellular reactive oxygen species formation in vitro and had the tendency to increase it in vivo. CONCLUSIONS: Rutin, likely due to its pro-oxidative effects, can exacerbate catecholamine cardiotoxicity depending on the dose used.

Flavonoid metabolite 3-(3-hydroxyphenyl)propionic acid formed by human microflora decreases arterial blood pressure in rats.

There are reports of positive effects of quercetin on cardiovascular pathologies, however, mainly due to its low biovailability, the mechanism remains elusive. Here, we report that one metabolite formed by human microflora (3-(3-hydroxyphenyl)propionic acid)relaxed isolated rat aorta and decreased arterial blood pressure in rats.

Oral administration of quercetin is unable to protect against isoproterenol cardiotoxicity.

Catecholamines are endogenous amines that participate in the maintenance of cardiovascular system homeostasis. However, excessive release or exogenous administration of catecholamines is cardiotoxic. The synthetic catecholamine, isoprenaline (isoproterenol, ISO), with non-selective ß-agonistic activity has been used as a viable model of acute myocardial toxicity for many years. Since the pathophysiology of ISO-cardiotoxicity is complex, the aim of this study was to elucidate the effect of oral quercetin pretreatment on myocardial ISO toxicity. Wistar-Han rats were randomly divided into four groups: solvent or quercetin administered orally by gavage in a dose of 10 mg kg(-1) daily for 7 days were followed by s.c. water for injection or ISO in a dose of 100 mg kg(-1). Haemodynamic, ECG and biochemical parameters were measured; effects on blood vessels and myocardial histology were assessed, and accompanying pharmacokinetic analysis was performed. Quercetin was unable to protect the cardiovascular system against acute ISO cardiotoxicity (stroke volume decrease, cardiac troponin T release, QRS-T junction elevation and histological impairment). The sole positive effect of quercetin on catecholamine-induced cardiotoxicity was the normalization of increased left ventricular end-diastolic pressure caused by ISO. Quercetin did not reverse the increased responsiveness of rat aorta to vasoconstriction in ISO-treated animals, but it decreased the same parameter in the control animals. Accompanying pharmacokinetic analysis showed absorption of quercetin and its metabolite 3-hydroxyphenylacetic acid formed by bacterial microflora. In conclusion, a daily oral dose of 10 mg kg(-1) of quercetin for 7 days did not ameliorate acute ISO-cardiovascular toxicity in rats despite minor positive cardiovascular effects.

Dexrazoxane provided moderate protection in a catecholamine model of severe cardiotoxicity.

Positive effects of dexrazoxane (DEX) in anthracycline cardiotoxicity have been mostly assumed to be associated with its iron-chelating properties. However, this explanation has been recently questioned. Iron plays also an important role in the catecholamine cardiotoxicity. Hence in this study, the influence of DEX on a catecholamine model of acute myocardial infarction (100 mg/kg of isoprenaline by subcutaneous injection) was assessed: (i) the effects of an intravenous dose of 20.4 mg/kg were analyzed after 24 h, (ii) the effects were monitored continuously during the first two hours after drug(s) administration to examine the mechanism(s) of cardioprotection. Additional in vitro experiments on iron chelation/reduction and influence on the Fenton chemistry were performed both with isoprenaline/DEX separately and in their combination. DEX partly decreased the mortality, reduced myocardial calcium overload, histological impairment, and peripheral haemodynamic disturbances 24 h after isoprenaline administration. Continuous 2 h experiments showed that DEX did not influence isoprenaline induced atrioventricular blocks and had little effect on the measured haemodynamic parameters. Its protective effects are probably mediated by inhibition of late myocardial impairment and ventricular fibrillation likely due to inhibition of myocardial calcium overload. Complementary in vitro experiments suggested that iron chelation properties of DEX apparently did not play the major role.

Cardiac biomarkers in a model of acute catecholamine cardiotoxicity.

Coronary heart disease and in particular its most serious form - acute myocardial infarction (AMI) - represents the most common cause of mortality in developed countries. Better prognosis may be achieved by understanding the etiopathogenetic mechanisms of AMI. Therefore, a catecholamine model of myocardial injury, which has appeared to be very similar to AMI in human in some aspect, was used. Male Wistar:Han rats were randomly divided into two groups: control group (saline) and isoprenaline group (ISO; synthetic catecholamine, 100 mg.kg(- 1) subcutaneously [s.c.]). After 24 hours, functional parameters were measured, biochemical markers in the blood and metals content in the heart tissue were analysed and histological examination was performed. ISO caused marked myocardial injury that was associated with myocardial calcium overload. Close correlation between myocardial impairment (i.e. serum TnT, stroke volume index and wet ventricles weight) and the levels of myocardial calcium was observed. Direct reactive oxygen species (ROS) involvement was documented only by non-significant increase in malonyldialdehyde 24 hours after ISO injury. Moreover, myocardial element analysis revealed no significant changes as for the content of zinc and iron while selenium and copper increased in the ISO group although it reached statistical significance only for the latter.

Atorvastatin Increases Endoglin, SMAD2, Phosphorylated SMAD2/3 and eNOS Expression in ApoE/LDLR Double Knockout Mice.

AIM: Endoglin is a homodimeric transmembrane glycoprotein that has been demonstrated to affect transforming growth factor beta (TGF-beta) signaling and endothelial nitric oxide synthase (eNOS) expression by affecting SMAD proteins in vitro. Thus, in this study we stepped forward to elucidate whether endoglin is co-expressed with SMAD2, phosphorylated SMAD2/3 proteins and eNOS in vivo in atherosclerotic lesions in ApoE/LDLR double knockout mice. In addition, we sought whether endoglin expression as well as the expression of SMAD2, phosphorylated SMAD2/3 and eNOS is affected by atorvastatin treatment. METHODS: Two-month-old female ApoE/LDLR double knockout mice were divided into two groups. The control group was fed with the western type diet whereas in the atorvastatin group, atorvastatin at dose 100 mg/kg per day was added to the same diet. Immunohistochemical and western blot analysis of endoglin, SMAD2, phosphorylated SMAD2/3 and eNOS expressions in aorta were performed. RESULTS: The biochemical analysis showed that administration of atorvastatin significantly decreased level of total cholesterol, VLDL, LDL, TAG, and significantly increased level of HDL cholesterol. Fluorescence immunohistochemistry showed endoglin co-expression with SMAD2, phosphorylated SMAD2/3 and eNOS in aortic endothelium covering atherosclerotic lesions in both control and atorvastatin treated mice. Western blot analysis demonstrated that atorvastatin significantly increased expression of endoglin, SMAD2, phosphorylated SMAD2/3, and eNOS in mice aorta. CONCLUSION: These findings suggest, that endoglin might be interesting marker of endothelial dysfunction and/or atherogenesis which is upregulated by statins implicating potential beneficial role of endoglin and its pathway in atherosclerosis.

Expression and activity of vitamin D receptor in the human placenta and in choriocarcinoma BeWo and JEG-3 cell lines.

Vitamin D receptor (VDR) regulates the expression of many genes involved in mineral metabolism, cellular proliferation, differentiation and drug biotransformation. We studied the expression and activity of VDR and its heterodimerization partner retinoid X receptor-alpha (RXRalpha) in choriocarcinoma trophoblast cell lines BeWo and JEG-3, in comparison with human isolated placental cytotrophoblasts and human full term placenta. We found that VDR and RXRalpha are localised in the human term placenta trophoblast and expressed in isolated cytotrophoblasts. However, we found low expression and no transcriptional activity of VDR in used choriocarcinoma cell lines. The inhibitor of DNA methylation, 5-deoxy-3'-azacytidine, and histone deacetylase inhibitor sodium butyrate partially restored the expression of VDR, suggesting an epigenetic suppression of the gene in choriocarcinoma cells. Differentiation of BeWo cells resulted in up-regulation of VDR mRNA. Finally, we observed a non-genomic effect of 1,25(OH)(2)D(3) in the activation of the extracellular signal-regulated kinase (ERK) signalling pathway in JEG-3 cells. In conclusion, our results suggest an epigenetic repression of VDR gene expression and activity in choriocarcinoma cell lines, and a non-genomic effect of 1,25(OH)(2)D(3) in JEG-3 cells.

The effects of lactoferrin in a rat model of catecholamine cardiotoxicity.

Lactoferrin is recently under intense investigation because of its proposed several pharmacologically positive effects. Based on its iron-binding properties and its physiological presence in the human body, it may have a significant impact on pathological conditions associated with iron-catalysed reactive oxygen species (ROS). Its effect on a catecholamine model of myocardial injury, which shares several pathophysiological features with acute myocardial infarction (AMI) in humans, was examined. Male Wistar rats were randomly divided into four groups according to the received medication: control (saline), isoprenaline (ISO, 100 mg kg(-1) s.c.), bovine lactoferrin (La, 50 mg kg(-1) i.v.) or a combination of La + ISO in the above-mentioned doses. After 24 h, haemodynamic functional parameters were measured, a sample of blood was withdrawn and the heart was removed for analysis of various parameters. Lactoferrin premedication reduced some impairment caused by ISO (e.g. a stroke volume decrease, an increase in peripheral resistance and calcium overload). These positive effects were likely to have been mediated by the positive inotropic effect of lactoferrin and by inhibition of ROS formation due to chelation of free iron. The failure of lactoferrin to provide higher protection seems to be associated with the complexity of catecholamine cardiotoxicity and with its hydrophilic character.

Direct administration of rutin does not protect against catecholamine cardiotoxicity.

High levels of catecholamines are cardiotoxic and may trigger acute myocardial infarction (AMI). Similarly, the synthetic catecholamine isoprenaline (ISO) evokes a pathological state similar to AMI. During AMI there is a marked increase of free iron and copper which are crucial catalysts of reactive oxygen species formation. Rutin, a natural flavonoid glycoside possessing free radical scavenging and iron/copper chelating activity, may therefore be potentially useful in reduction of catecholamine cardiotoxicity as was previously demonstrated after its long-term peroral administration. Male Wistar:Han rats received rutin (46 or 11.5 mg kg(-1) i.v.) alone or with necrogenic dose of ISO (100 mg kg(-1) s.c.). Haemodynamic parameters were measured 24h after drug application together with analysis of blood, myocardial content of elements and histological examination. Results were confirmed by cytotoxicity studies using cardiomyoblast cell line H9c2. Rutin in a dose of 46 mg kg(-1) aggravated ISO-cardiotoxicity while the dose of 11 mg kg(-1) had no effect. These unexpected results were in agreement with in vitro experiments, where co-incubation with larger concentrations of rutin significantly augmented ISO cytotoxicity. Our results, in contrast to previous studies in the literature, suggest that the reported positive effects of peroral administration of rutin were unlikely to have been mediated by rutin per se but probably by its metabolite(s) or by some other, at this moment, unknown adaptive mechanism(s), which merit further investigation.

Microdispersed Oxidized Cellulose as a novel potential substance with hypolipidemic properties.

OBJECTIVE: The aim of this study was to determine whether Microdispersed Oxidized Cellulose (MDOC) possesses a hypolipidemic effect in apolipoprotein-E/low-density lipoprotein receptor double-knockout (ApoE/LDLR-deficient) mice and the possible mechanism of this effect in mice. METHODS: Female ApoE/LDLR-deficient mice subdivided into two groups were fed with a Western-type diet for 8 wk, and the experimental group was supplemented with 5% MDOC for 8 wk. Female C57BL/6J mice were fed an atherogenic diet containing 5% MDOC or pectin for the determination of a possible hypolipidemic mechanism of MDOC action. RESULTS: Biochemical analysis showed that 5% MDOC treatment significantly decreased total cholesterol by 20% (P = 0.0338) and very-LDL cholesterol by 21% (P = 0.0110) and significantly increased the level of high-density lipoprotein cholesterol by 62% (P = 0.0172) when compared with non-treated ApoE/LDLR-deficient mice. The results Association of Official Analytical Chemists method 991.43 revealed that MDOC contains 59.78 +/- 5.0% of fiber. Furthermore, it was demonstrated that administration of MDOC did not affect cholesterol absorption in the small intestine. Using C57BL/6J mice, MDOC and pectin treatments decreased cholesterol content in liver and increased fermentation in the gut in vivo. In vitro experiments confirmed that MDOC is fermentable under conditions mimicking those in the large intestine. CONCLUSION: We demonstrated hypolipidemic effects of MDOC in ApoE/LDLR-deficient mice. Moreover, we propose that MDOC is a hypolipidemic soluble fiber acting probably by increased fermentation and production of short-chain fatty acids in the large intestine in mice. We propose that MDOC might be a possible source of soluble fiber for use in dietary supplements.

Atorvastatin has hypolipidemic and anti-inflammatory effects in apoE/LDL receptor-double-knockout mice.

Statins are first-line pharmacotherapeutic agents for hypercholesterolemia treatment in humans. However the effects of statins in animal models of atherosclerosis are not very consistent. Thus we wanted to evaluate whether atorvastatin possesses hypolipidemic and anti-inflammatory effects in mice lacking apolipoprotein E/low-density lipoprotein receptor (apoE/LDLR-deficient mice). Two-month-old female apoE/LDLR-deficient mice (n=24) were randomly subdivided into 3 groups. The control group of animals (n=8) was fed with the western type diet (atherogenic diet) and in other two groups atorvastatin was added to the atherogenic diet at the dosage of either 10 mg/kg or 100 mg/kg per day for a period of 2 months. Biochemical analysis of lipids, ELISA analysis of monocyte chemotactic protein-1 (MCP-1) in blood, quantification of lesion size and expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) in the atherosclerotic lesion by means of immunohistochemistry and Western blot analysis were performed. The biochemical analysis showed that administration of atorvastatin (100 mg/kg/day) significantly decreased level of total cholesterol, lipoproteins (VLDL and LDL), triacylglycerol, and moreover significantly increased level of HDL. ELISA analysis showed that atorvastatin significantly decreased levels of MCP-1 in blood and immunohistochemical and Western blot analysis showed significant reduction of VCAM-1 and ICAM-1 expression in the vessel wall after atorvastatin treatment (100 mg/kg/day). In conclusion, we demonstrated here for the first time strong hypolipidemic and anti-inflammatory effects of atorvastatin in apoE/LDLR-deficient mice. Thus, we propose that apoE/LDLR-deficient mice might be a good animal model for the study of statin effects on potential novel markers involved in atherogenesis and for the testing of potential combination treatment of new hypolipidemic substances with statins.

Endothelial expression of endoglin in normocholesterolemic and hypercholesterolemic C57BL/6J mice before and after atorvastatin treatment.

Endoglin (CD105) is a homodimeric transmembrane glycoprotein strongly related to transforming growth factor (TGF)-beta signaling and many pathological states. In this study, we wanted to evaluate whether endoglin is expressed in normocholesterolemic and hypercholesterolemic C57BL/6J mice as well as whether it is affected by atorvastatin treatment in these mice. C57BL/6J mice were fed with chow diet or an atherogenic diet for 12 weeks after weaning. In 2 atorvastatin-treated groups, mice were fed the same diets (chow or atherogenic) as described above except atorvastatin was added at the dosage of 10 mg x kg(-1) x day(-1) for the last 8 weeks before euthanasia. Biochemical analysis of blood samples revealed that administration of atherogenic diet significantly increased levels of total cholesterol, VLDL, LDL, and decreased levels of HDL. Atorvastatin treatment resulted in a significant decrease in total cholesterol and VLDL only in mice fed by atherogenic diet. Quantitative stereological analysis revealed that atorvastatin significantly decreased endothelial expression of endoglin in C57BL/6J mice fed the atherogenic diet. In conclusion, we demonstrated that endothelial expression of endoglin is upregulated by hypercholesterolemia and decreased by the hypolipidemic effect of atorvastatin in C57BL/6J mice, suggesting that endoglin expression could be involved in atherogenesis.

Atorvastatin slows down the deterioration of inner ear function with age in mice.

Statins have revolutionized the treatment of hypercholesterolemia due to their ability to inhibit cholesterol biosynthesis. Their immunomodulatory and anti-inflammatory effects and positive effects on the treatment of atherosclerosis and its complications are well known. Here, we describe the effects of statins on the treatment of presbycusis in C57BL/6J mice. In this strain with accelerated aging, we demonstrate that animals treated with atorvastatin (10mg/kg per day in chow diet) for 2 months showed larger amplitudes of distortion product otoacoustic emissions (DPOAE) than did the non-treated control group. This finding indicates a better survival of outer hair cell function in the inner ear of C57BL/6J mice. The observed decreased expression of intercellular and vascular adhesion molecules in the aortic wall of atorvastatin-treated animals suggests that reducing endothelial inflammatory effects may contribute to the positive effect of atorvastatin on the amplitudes of DPOAE by influencing the blood supply to the inner ear. No such beneficial effect of statins was found in apoE(-/-) mice treated with atorvastatin under the same conditions. Our results suggest that statins could also slow down the age-related deterioration of hearing in man.

Atorvastatin has distinct effects on endothelial markers in different mouse models of atherosclerosis.

PURPOSE: Atherosclerosis is a progressive process that initially involves endothelial dysfunction. We investigated the effects of atorvastatin on both lipid parameters, and VCAM-1 and ICAM-1 expression in apoE-deficient or wild type C57BL/6J mice. METHODS: The C57BL/6J mice were fed with either chow or an atherogenic diet for 12 weeks. Male apoE-deficient mice were fed with the chow diet for 12 weeks. In 3 atorvastatin treated groups mice were fed the same diet as described above except atorvastatin was added to the diet at the dosage of 10 mg/kg per day for the last 8 weeks before euthanasia. RESULTS: Biochemical analysis showed that atorvastatin significantly decreased total cholesterol levels and VLDL in C57BL/6J mice fed with atherogenic diet but increased serum lipid levels in apoE-deficient mice. Stereological analysis of the immunohistochemical staining revealed that atorvastatin reduced endothelial expression of ICAM-1 and VCAM-1 only in C57BL/6J mice on chow diet. CONCLUSION: We have demonstrated that endothelial expression of both VCAM-1 and ICAM-1 does not correlate with cholesterol levels in these mice. Moreover, we showed that 8-week administration of atorvastatin decrease endothelial expression of VCAM-1 and ICAM-1 in C57BL/6J wild type mice beyond its lipid lowering effect but not in C57BL/6J wild type mice fed by atherogenic diet or in apoE-deficient mice.

Effects of oral alpha-tocopherol on lung response in rat model of allergic asthma.

OBJECTIVE AND BACKGROUND: Asthma is a chronic inflammatory disease in which an oxidant/antioxidant imbalance plays an important role. d-alpha-tocopherol (biologically the most active form of vitamin E) has redox properties and by scavenging the free radicals can act as an antioxidant. The aim of this study was to examine the effects of orally administered alpha-tocopherol in a rat model of allergic asthma. METHODOLOGY: Actively sensitized rats (OA) were treated with alpha-tocopherol (400 mg/kg/day for 10 days) or vehicle; 1 h after the last dose, they were challenged with antigen aerosol. The antigen-induced airway hyperresponsiveness to direct bronchoconstrictor (serotonin), the inflammatory cell infiltrate and histological changes were determined 1 or 24 h after the antigen challenge. RESULTS: Alpha-tocopherol pretreatment was not significantly effective at reducing the studied parameters when compared with controls, even though there was a tendency to a reduction in bronchial responsiveness and in eosinophil and neutrophil infiltration. CONCLUSION: Alpha-tocopherol when administered in the chosen study design in an animal model of asthma had no major effect on airway inflammation. The effect of antioxidants deserves further evaluation.

MDOC and atorvastatin have potential antiinflammatory effects in vascular endothelium of apoE-/- mouse model of atherosclerosis.

Members of the immunoglobulin superfamily of endothelial adhesion molecules, vascular cell adhesion molecule (VCAM-1) and intercellular cell adhesion molecule (ICAM- 1), strongly participate in leukocyte adhesion to the endothelium and play an important role in all stages of atherogenesis. The aim of this study was to detect and quantify the changes of endothelial expression of VCAM-1, and ICAM-1 in the vessel wall after the short-term administration of simvastatin, atorvastatin, and micro dispersed derivatives of oxidised cellulose (MDOC) in apolipoprotein-E-deficient (apoE(-/-)) mice atherosclerotic model. Hyperlipidemic apoE(-/-) mice (n = 32) received normal chow diet or diet containing simvastatin or atorvastatin 10 mg/kg/day or MDOC 50 mg/kg/day. Total cholesterol, VLDL, LDL, HDL and TAG were measured and the endothelial expression of VCAM-1 and ICAM-1 was visualized and quantified by means of immunohistochemistry and stereology, respectively. Total cholesterol levels was insignificantly lowered only in MDOC treated mice but not in mice treated with statins. ICAM-1 endothelial expression was not affected by neither simvastatin nor MDOC treatment. However, significant diminution of VCAM-1 endothelial expression was observed in both atorvastatin and MDOC treated mice. These results provide new information of potential hypolipidemic substance MDOC and its potential anti-inflammatory effects. Furthermore, we have confirmed anti-inflammatory effects of atorvastatin independent of plasma cholesterol lowering. Thus, the results of this study show potential benefit of both MDOC and atorvastatin treatment in apoE(-/-) mouse model of atherosclerosis suggesting their possible combination might be of interest.

Endoglin expression in hyper-cholesterolemia and after atorvastatin treatment in apoE-deficient mice.

PURPOSE: Endoglin (CD105) is a marker of activated endothelium and a modulator of TGF-beta signaling. We hypothesized whether endothelial expression of endoglin is changed in hypercholesterolemia as well as whether its expression is affected by atorvastatin treatment in apoE-deficient mice. METHODS: ApoE-deficient mice were fed with the chow diet for either 4 weeks or for 12 weeks respectively. In two treated groups, mice were fed with chow diet except atorvastatin was added to the diet for the last 4 weeks or for the last 8 weeks respectively, before euthanasia. RESULTS: Administration of atorvastatin did not affect lipid parameters after 4 weeks treatment, however increased all lipid parameters after 8 weeks of treatment. Stereological analysis of immunohistochemical staining revealed that atorvastatin significantly decreased endoglin expression in endothelium after 4 weeks of treatment but increased it after 8 weeks of treatment. CONCLUSIONS: This study demonstrates that endoglin is expressed by aortic endothelium showing similar staining patterns like other markers involved in the process of atherosclerosis. In addition, we showed that endoglin expression in endothelium could be affected by the administration of atorvastatin beyond its lipid lowering effects in apoE-deficient mice.

Vimentin expression during altered spermatogenesis in rats.

The collapse of vimentin caused by some xenobiotics correlates with the loss of structural integrity of the seminiferous epithelium. In this study, we investigated the effect of busulphan (an anticancer drug with toxic effects on dividing germ cells) on vimentin filament distribution in rat seminiferous epithelium and compared it with changes found in testes of unilaterally cryptorchid rats. In the seminiferous epithelium, the vimentin labelling was observed only in the Sertoli cells, showing a stage-specific arrangement of the filaments. Both busulphan treatment and cryptorchism caused altered distribution of vimentin filaments in the Sertoli cells. In both models, the apical vimentin filaments collapsed towards the nuclei and were disorganized in the basal region of the Sertoli cells while the germ cells were diminished in the epithelium. After the busulphan effect subsided (4 weeks after administration), spermatogenesis began to restore and vimentin filaments began to organize in basal and perinuclear regions of Sertoli cells among the spermatogonia and spermatocytes. Vimentin labelling of the sloughed material in the lumen of cryptorchid testes (but not in busulphan treated animals) was observed. We conclude that the Sertoli cell vimentin filaments play an important role in the maintenance of spermatogenesis, their damage is associated with the seminiferous epithelium disintegration and their restoration with a recovery of spermatogenesis after the unfavourable conditions subside.

99mTc demotate 1: biodistribution and elimination characteristics in rats.

BACKGROUND AND METHODS: In this study, we investigated the biodistribution and elimination characteristics of a new radiolabelled somatostatin analogue, 99mTc demotate 1, in rats by in-vivo biodistribution and elimination experiments, perfused rat liver and kidney experiments and micro-autoradiography of renal tissue. RESULTS: Rapid clearance from blood and most organs was found. High and long-term uptake in organs with high density of somatostatin receptors (the adrenals and pancreas) and in stomach and intestine was reduced in non-radiolabelled octreotide pretreated animals. The predominant urine excretion was associated with an accumulation of 99mTc demotate 1 in the kidney, mainly in the renal cortex. This uptake was not affected by non-radiolabelled octreotide pretreatment. CONCLUSION: 99mTc demotate 1 is a prospective radiopharmaceutical for use in human medicine in somatostatin receptor-positive tumour imaging and its potential should be confirmed in further experiments and clinical trials.