[TMPRSS2-Erg/AR-V7: Prognostic value of tests in urine and biopsy rince material in prostate cancer]. / TMPRSS2-Erg/AR-V7 : valeur diagnostique des tests urinaires et sur liquides biopsiques dans le cancer prostatique.

INTRODUCTION: Nowadays, diagnostic biomarker research is oriented on a genomic characterisation of prostate cancer (PCa). This study evaluated diagnostic values of TMPRSS2-Erg fusion transcripts expression (TE) and androgen receptor variant 7 (AR-V7) on urine (tU) and biopsic rince material (tLRB) samples. MATERIALS AND METHODS: TE and AR-V7 have been tested by RT-PCR and RT-qPCR on urine and biopsies' rince liquid on 372 patients referred for prostate biopsies. RESULTS: Two hundred thirty-three patients (62%) were diagnosed with PCa. tU.AR-V7 was positive for 15 healthy patients (28%) and 30 patients diagnosed with PCa (37%). tLRB.AR-V7 was positive for 66 patients (42%) diagnosed with PCa. Concerning TE for patients diagnosed with PCa, tU was positive for 59 patients (54%) and tLRB for 132 (55%). TE and TE/AR-V7 combination were significantly associated with PCa (P<0.001), as tLRB.AR-V7 (P<0.001). Sensitivity and specificity for TE/AR-V7 combination for PCa were respectively: tU.TE/AR-V7 67% and 70%, tLRB.TE/AR-V7 68.8% and 71%, and, tUtLRB.TE/AR-V7 83% and 60%. There was no benefit for AR-V7 and TE association versus TE alone when comparing AUC. CONCLUSION: AR-V7 is not specific of PCa because of detection on healthy patients. This study did not managed to show a sufficient diagnostic value for TE/AR-V7 combination on urine and biospic rince material tests. LEVEL OF EVIDENCE: 3.

Implication of the human Binder of SPerm Homolog 1 (BSPH1) protein in capacitation.

Binder of SPerm (BSP) proteins are a family of proteins expressed exclusively in the male reproductive tract (seminal vesicles or epididymis) of several mammalian species. They are known to promote capacitation, a sperm maturation step essential for fertilization. Our recent studies have shown that in human, the Binder of SPerm Homolog 1 (BSPH1) is expressed solely in epididymal tissues. The goal of the current study was to characterize BSPH1 and evaluate its effect on different sperm functions. A human recombinant BSPH1 (rec-BSPH1) was produced, purified and refolded. Rec-BSPH1 was found to share many characteristics with other members of the BSP superfamily, as it was able to bind gelatin and heparin as well as capacitate sperm. Rec-BSPH1 had no effect on sperm acrosome reaction or any sperm motility parameters. Native BSPH1 was localized on the equatorial segment, post-acrosomal segment and neck of ejaculated human sperm. Rec-BSPH1, following incubation with washed ejaculated human sperm, exhibited binding patterns similar to the native protein. These results show that the human epididymal BSPH1 shares many biochemical and functional characteristics with BSP proteins secreted by seminal vesicles of ungulates, and behaves similarly to its murine epididymal orthologue BSPH1. This study of human BSPH1 brings us one step closer to understanding the importance of this protein in male fertility.

Search for light dark matter in XENON10 data.

We report results of a search for light (≲10 GeV) particle dark matter with the XENON10 detector. The event trigger was sensitive to a single electron, with the analysis threshold of 5 electrons corresponding to 1.4 keV nuclear recoil energy. Considering spin-independent dark matter-nucleon scattering, we exclude cross sections σ(n)>7×10(-42) cm(2), for a dark matter particle mass m(χ)=7 GeV. We find that our data strongly constrain recent elastic dark matter interpretations of excess low-energy events observed by CoGeNT and CRESST-II, as well as the DAMA annual modulation signal.

Dark matter results from 100 live days of XENON100 data.

We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0 × 10(-45) cm(2) for a WIMP mass of 50 GeV/c(2) at 90% confidence level.

First dark matter results from the XENON100 experiment.

The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter weakly interacting massive particles (WIMPs) scattering off 62 kg of liquid xenon in an ultralow background dual-phase time projection chamber. In this Letter, we present first dark matter results from the analysis of 11.17 live days of nonblind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the predefined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 × 10⁻44 cm² for 55 GeV/c² WIMPs at 90% confidence level. Below 20 GeV/c², this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.

Renal permeability alteration precedes hypertension and involves bradykinin in the spontaneously hypertensive rat.

Vascular permeability disorders have been described in experimental models, as well as in human hypertension. We recently described the fact that vascular permeability to albumin is heterogeneous in the normal rat. In the present study, we examine the contents of Evans blue dye (EB) bound to albumin in selected organs of unanesthetized Wistar Kyoto (WKY) and in spontaneously hypertensive rats (SHR) at various stages of development of hypertension. EB was injected in the caudal vein of paired 4, 8, 12, and 16-wk-old WKY and SHR. Rats were killed 10 min after EB injection and extraction of the marker was measured in selected tissues. In additional 4 and 16-wk-old animals, bradykinin B1 and B2 receptor antagonists (BKA) were also injected with EB. Renal contents of EB bound to albumin were higher in the SHR than in the WKY: 196 +/- 9, 202 +/- 10, 182 +/- 7, and 196 +/- 9, compared with 158 +/- 8, 155 +/- 7, 138 +/- 7, and 118 +/- 6 micrograms/g dry tissue, in the 4, 8, 12, and 16-wk-old rats, respectively. In the 4-wk-old SHR and WKY, blood pressure values were normal and comparable, yet the alteration in EB permeability was already present in the SHR. Both BKA failed to alter the renal EB extravasation in the WKY, but the B2-BKA restored the renal permeability to control levels in the SHR. We conclude that a selective defect in the renal vascular permeability to EB developed in the SHR. Since this finding precedes hypertension and is corrected by a selective B2-BKA, it is suggested that bradykinin is involved at an early stage of the disease in the SHR.

The effect of ketone bodies on renal ammoniogenesis.

Infusion of ketone bodies to ammonium chloride-loaded acidotic dogs was found to induce significant reduction in urinary excretion of ammonia. This effect could not be attributed to urinary pH variations. Total ammonia production by the left kidney was measured in 25 animals infused during 90 min with the sodium salt of D,L-beta-hydroxybutyric acid adjusted to pH 6.0 or 4.2. Ketonemia averaged 4.5 mM/liter. In all experiments the ammonia content of both urine and renal venous blood fell markedly so that ammoniogenesis was depressed by 60% or more within 60 min after the onset of infusion. Administration of equimolar quantities of sodium acetoacetate adjusted to pH 6.0 resulted in a 50% decrease in renal ammonia production. Infusion of ketone bodies adjusted to pH 6.0 is usually accompanied by a small increase in extracellular bicarbonate (3.7 mM/liter). However infusion of D,L-sodium lactate or sodium bicarbonate in amounts sufficient to induce a similar rise in plasma bicarbonate resulted in only a slight decrement in ammonia production (15%). The continuous infusion of 5% mannitol alone during 90-150 min failed to influence renal ammoniogenesis. Infusion of pure sodium-free beta-hydroxybutyric acid prepared by ion exchange (pH 2.2) resulted in a 50% decrease in renal ammoniogenesis in spite of the fact that both urinary pH and plasma bicarbonate fell significantly. During all experiments where ketones were infused, the renal extraction of glutamine became negligible as the renal glutamine arteriovenous difference was abolished. Renal hemodynamics did not vary significantly. Infusion of beta-hydroxybutyrate into the left renal artery resulted in a rapid decrease in ammoniogenesis by the perfused kidney. The present study indicates that ketone bodies exert their inhibitory influence within the renal tubular cell. Since their effect is independent of urinary or systemic acid-base changes, it is suggested that they depress renal ammoniogenesis by preventing the transformation of glutamine and glutamate into alpha-ketoglutarate in the mitochondria of the renal tubular cell.

Bioequivalence of abacavir generic and innovator formulations under fasting and fed conditions.

OBJECTIVE: Abacavir sulfate is a synthetic carbocyclic nucleoside analogue indicated for the treatment of HIV-1 infection in combination with other antiretroviral agents. The objective of the current study was to determine the bioequivalence between a generic formulation of abacavir and the innovator product. MATERIAL AND METHODS: A total of 80 subjects were randomly assigned to receive a single 300 mg oral dose of abacavir sulfate as the generic (Ranbaxy-Abacavir, Ranbaxy Laboratories Ltd., equivalent to 300 mg of abacavir) and innovator (Ziagen, GlaxoSmithKline) tablet formulations in 2-way crossover studies performed under fasting (n=40) and fed (n=40) conditions. Multiple blood samples were collected over 14 hours and plasma concentrations of abacavir were assayed using an LC/MS/MS method with a limit of quantitation of 25.0 ng/ml. Pharmacokinetic (PK) parameters were calculated using noncompartmental methods. RESULTS: Under fasting conditions, geometric mean area under the curve from time 0 to the last measurable concentration (AUC(0-t)), area under the curve extrapolated to infinity (AUC(0-infinity) and maximum plasma concentrations (Cmax) of abacavir for the generic (5565 ng x h/ml, 5668 ng x h/ml and 2526 ng/ml, respectively) and innovator (5675 ng x h/ml, 5770 ng x h/ml and 2528 ng/ml, respectively) products were very similar. Under fed conditions, mean values of AUC(0-t) AUC(0-infinity) and Cmax for the generic (4487 ng x h/ml, 4571 ng x h/ml and 1841 ng/ml, respectively) and innovator (4574 ng x h/ml, 4654 ng x h/ml and 1781 ng/ml, respectively) formulations were also very similar. Ratios of LSM and 90% confidence intervals of PK parameters between the 2 formulations were within 80.0 - 125.0% under fasting and fed conditions, suggesting that the 2 tablet formulations resulted in similar rate and extent of bioavailability. Adverse events for the generic and innovator products were similar in nature and frequency in the fasting and fed studies. CONCLUSIONS Based on the above results, the generic tablet formulation of abacavir developed by Ranbaxy should be equally effective as the innovator product.

Epididymal Binder of SPerm genes and proteins: what do we know a decade later?

Binder of SPerm (BSP) proteins from ungulates (more specifically bull, bison, buffalo, stallion, boar, goat, and ram) have been extensively studied in the past 30 years. These proteins secreted by seminal vesicles constitute between 1 and 60% of total seminal plasma proteins depending on the species. In addition to sharing many biochemical characteristics such as the ability to bind to gelatin, glycosaminoglycans, choline phospholipids, and lipoproteins, they also share a main function: promoting sperm capacitation. Over the last 10 years, new members of the BSP superfamily have been discovered. These proteins found in bulls, humans, mice, and rabbits are expressed in the epididymides rather than in seminal vesicles and constitute only a minute percentage of the seminal plasma proteins. However, they share many characteristics with BSPs expressed by accessory glands including their structure, their ability to bind to the aforementioned BSP ligands, as well as their ability to promote sperm capacitation. More investigations need to be done on epididymal BSP proteins, but studies described in this review constitute a solid foundation toward deciphering the significance of epididymal BSP proteins in male fertility.

Hypertension in elderly patients. A comparative study between indapamide and hydrochlorothiazide.

Diuretic therapy is still regarded as the first-step approach in elderly patients with benign or moderate arterial hypertension. Traditional preparations such as thiazides, or potassium-sparing agents, are not devoid of significant side effects, however. Indapamide, a nonthiazide diuretic, has been shown to reduce blood pressure at low doses, in several clinical reports. In the present study, the effect of indapamide (2.5 mg per day) was compared with that of hydrochlorothiazide (50 mg per day) on blood pressure and serum chemistry of 47 elderly hypertensive patients (ages 65 to 91). After a six-week placebo-treatment period, patients were randomly assigned to receive either indapamide or hydrochlorothiazide. At that moment, blood pressure of patients in the supine position averaged 185 +/- 2/107 +/- 2, and 181 +/- 3/102 +/- 2 mm Hg, in the indapamide and hydrochlorothiazide groups, respectively. After 48 weeks of therapy, blood pressure was 162 +/- 3/89 +/- 2 and 170 +/- 2/94 +/- 2 mm Hg in the same groups, respectively. Serum sodium levels remained unchanged in indapamide-treated patients, but decreased progressively from 141 +/- 1 to 134 +/- 1 meq/liter in hydrochlorothiazide-treated patients. Serum potassium levels decreased from 4.50 +/- 0.12 to 4.04 +/- 0.10 meq/liter in indapamide-treated patients, whereas in the patients receiving hydrochlorothiazide, kalemia decreased from 4.23 +/- 0.09 to 3.33 +/- 0.01 meq/liter. Finally, serum uric acid levels did not increase significantly in patients receiving indapamide, whereas it rose from 6.5 +/- 0.4 to 8.7 +/- 0.3 mg/dl in patients treated with hydrochlorothiazide. In conclusion, indapamide resulted in a better control of systolic and diastolic blood pressure in this group of elderly hypertensive patients. In addition, the effect of each drug on blood chemistry differed markedly: indapamide failed to alter significantly the serum ionic composition, whereas hydrochlorothiazide was associated with both hyponatremia and hypokalemia.

Effect of indapamide on phosphate metabolism and vascular reactivity.

The effect of indapamide, a nonthiazide diuretic, on urinary electrolytes, renal hemodynamics, and tissue inorganic phosphate was examined in normal anesthetized rats, as well as on vascular reactivity in vitro. Intravenous injections of 0.5 ml/kg of 1 x 10(-5), 1 x 10(-4), and 1 x 10(-3) M indapamide solutions reduced mean arterial pressure from 123 to 114, 130 to 113, and 128 to 114 mm Hg and the plasma phosphate concentrations from 6.4 to 4.2, 6.6 to 4.8, and 7.0 to 4.5 mg/dl, respectively. Similarly, there was a dose-dependent effect of indapamide on fractional excretion of phosphate, which increased from 17 to 44, 24 to 53, and 18 to 75 percent in animals receiving increasing doses of indapamide. This effect of indapamide on the external phosphate balance was associated with significant reduction of kidney cortex and skeletal muscle total inorganic phosphate. In contrast, fractional sodium excretion augmented by 2.6, 2.5, and 2.5 percent, respectively, at each dose of indapamide. This compound also reduced significantly the contractions of strips of rabbit aorta and mesenteric artery elicited by norepinephrine (0.01 to 1.0 micrograms/ml). These results suggest that indapamide-induced reduction of blood pressure could be mediated by an effect of this drug on phosphate balance, and probably on vascular reactivity.

Indapamide is superior to thiazide in the preservation of renal function in patients with renal insufficiency and systemic hypertension.

The long-term effects of indapamide or hydrochlorothiazide on blood presssure and renal function were examined in patents with impaired renal function and moderate hypertension. Both drugs controlled hypertension and blood pressure remained normal during the 2 years of the study. Despite this comparable control of hypertension, indapamide therapy was associated with a 28.5 +/- 4.4% increase in creatinine clearance, whereas treatment with hydrochlorothiazide was associated with a 17.4 +/- 3.0% decrease in creatinine clearance. The results of the study indicate that indapamide is superior to hydrochlorothiazide in the treatment of patients with impaired renal function and moderate hypertension.

Role of eicosanoids in PAF-induced increases of the vascular permeability in rat airways.

1. Platelet activating factor (PAF; 1.0 and 5.0 micrograms kg-1) injected in the tail vein of unanaesthetized rats dose-dependently increased the vascular permeability of the trachea, upper and lower bronchi (up to 400%) as measured by the extravasation of Evans blue dye. The permeability of the parenchyma was not affected by PAF treatment. 2. Pretreatment of the animals with an intravenous injection of the PAF antagonist BN-52021 (10 mg kg-1) abolished almost totally the vascular permeability changes elicited by PAF injection (5.0 micrograms kg-1). 3. Pretreatment of the animals with intravenous injections of inhibitors of thromboxane formation, indomethacin (10 mg kg-1) and compound OKY-046 (10 mg kg-1), and thromboxane antagonist, compound L-655,240 (5 mg kg-1), partially reduced PAF effects in the airways (from 28 to 69%). The thromboxane mimic U-44069 (5.0 micrograms kg-1) did not modify the vascular permeability of rat airways. The effect of a low dose of PAF (0.1 microgram kg-1) on the vascular permeability of the trachea and bronchi (but not of the parenchyma) was potentiated by compound U-44069 (5.0 micrograms kg-1) or noradrenaline (400 ng kg-1) whereas the effect of a high dose of PAF (5.0 micrograms kg-1) was not affected. 4. Neither the peptidoleukotriene antagonist MK-571 (10 mg kg-1) nor the 5-lipoxygenase inhibitor, L-663,536 (10 mg kg-1) given before the injection of PAF (5.0 micrograms kg-1) affected the protein extravasation in rat lung tissues. 5. These data suggest that the effect of PAF on rat vascular permeability is partly modulated by thromboxane formation although thromboxanes have no direct effect on the permeability. Thromboxane may act via a vasoconstriction that increases hydrostatic pressure and potentiates the extravasation elicited by PAF effect on endothelial cells. 6. Leukotrienes do not appear to be involved in the changes of rat airway permeability induced by PAF.

Phosphoramidon blocks big-endothelin-1 but not endothelin-1 enhancement of vascular permeability in the rat.

1. Changes in vascular permeability following intravenous injections of human big-endothelin-1 (big-ET-1) and endothelin-1 (ET-1) were measured by extravasation of Evans blue dye (EB, 20 mg kg-1) in selected tissues. 2. A low dose of big-ET-1 (40 pmol kg-1) failed to alter vascular permeability but a dose of 400 pmol kg-1 increased EB extravasation in the trachea, upper and lower bronchi, and lung parenchyma by 55 to 69% (P < 0.05). Vascular permeability was also enhanced in the liver, spleen, kidney, heart, and diaphragm by 20, 14, 41, 25, and 67%, respectively (P < 0.05). 3. Upon injection of ET-1 (400 pmol kg-1), EB extravasation increased in the upper and lower bronchi, lung parenchyma, liver, pancreas, kidney, heart, and diaphragm. 4. Administration of ET-1 and big-ET-1 was not associated with significant systemic responses. 5. Pretreatment with phosphoramidon (PA) blocked the response to big-ET-1 in all tissues examined but this inhibitor failed to alter the response to ET-1. 6. We conclude from these results that the dose-dependent increase in vascular permeability induced by big-ET-1 in various tissues follows its conversion to ET-1 by the endothelin converting enzyme, a PA-sensitive process.

Effect of PAF on rat lung vascular permeability: role of platelets and polymorphonuclear leucocytes.

1. The objectives of the present experiments were to assess the contribution of polymorphonuclear leucocytes (PMNLs), platelets and their products such as thromboxane A2 (TxA2), histamine and 5-hydroxytryptamine to platelet activating factor (PAF)-mediated protein extravasation in rat lungs. 2. Intravenous injection of PAF (1.0 and 5.0 micrograms kg-1) increased dose-dependently (up to 7.5 fold) the vascular permeability of the trachea, upper and lower bronchi to Evans blue dye (EB), a marker of albumin extravasation. The permeability of the pulmonary parenchyma was not affected significantly by PAF. 3. Thrombocytopenia induced by administration of the IgG fraction of goat anti-rat platelet serum (APS; 15 mg 100 g-1, i.p., 16-18 h) reduced by 55, 58 and 40% the effects of the lower dose of PAF (1.0 microgram kg-1) and by 31, 23 and 15% the effects of the higher dose of PAF (5.0 micrograms kg-1) on the permeability of the trachea, upper and lower bronchi respectively to albumin. 4. PMNL depletion induced by administration of rabbit anti-rat polymorphonuclear serum (ANS; 2 mg kg-1, i.v., 24 h) did not reduce significantly the effects of the lower dose of PAF (1.0 microgram kg-1) on the airways, however the effects of the higher dose of PAF (5.0 micrograms kg-1) on the permeability of the trachea, upper and lower bronchi to albumin were reduced by 43, 25 and 23% respectively. 5. The injection of both the anti-platelet and the anti-PMNL sera reduced by 61, 62 and 96% the effects of the lower dose of PAF (1.0 microg kg-1) and by 44, 39 and 47% the effects of the higher dose of PAF (5.0 microg kg-1) on the permeability of the trachea, upper and lower bronchi respectively.6. The combined injection of the TxA2-mimetic (U-44069; 5.0 microg kg-1) and PAF (1.0 and 5.0 microg kg-1)in thrombocytopenic rats overcame the vascular permeability decrease induced by APS treatment.7. Pretreatment of the animals with a combination of antagonists to histamine (mepyramine;3.0 mg kg-1) and 5-hydroxytryptamine (methysergide; 2.5 mg kg-1) did not cause a significant inhibition of the effect of PAF (1.0 and 5.0 microg kg-1) on EB extravasation in the airways.8. These data show that the effect of intravenous PAF on rat vascular permeability is partly modulated by polymorphonuclear leucocyte and platelet activation. Our results suggest that following its release,TxA2 could increase postcapillary hydrostatic pressure by inducing a venoconstriction and potentiate the extravasation elicited by PAF. These results do not suggest a major role for histamine and/or 5-hydroxytryptamine on PAF-induced albumin extravasation.

Enhancement by endothelin-1 of microvascular permeability via the activation of ETA receptors.

1. The objective of the present experiments was to assess the involvement of endothelin-A (ETA) receptors in mediating the effects of endothelin-1 on microvascular permeability in conscious rats. 2. Bolus injection of endothelin-1 (0.1 and 1 nmol kg-1, i.v.) resulted in a dose-dependent prolonged pressor effect preceded by a transient depressor response. These changes were accompanied by a dose-dependent loss of plasma volume. Endothelin-1 (1 nmol kg-1) enhanced the vascular permeability of the upper and lower bronchi, kidney, stomach, duodenum and spleen (up to 270%) as measured by the extravasation of Evans blue dye. 3. Pretreatment of the animals with the selective ETA receptor antagonist, BQ-123 (1 mg kg-1, i.v.) significantly blunted the pressor response to endothelin-1 without affecting the depressor response. BQ-123 inhibited by 87% the endothelin-1 (1 nmol kg-1)-induced plasma volume loss. BQ-123 markedly attenuated protein extravasation elicited by endothelin-1 in the upper and lower bronchi and kidney, whereas it completely inhibited the permeability effect of endothelin-1 in the stomach and duodenum. BQ-123 by itself had no significant effect on the parameters studied. 4. The endothelin-1 analogue, [Trp(For)21]-endothelin-1, in which Trp21 is formylated, was as potent a pressor agent as endothelin-1, but had no depressor action. Bolus injection of [Trp(For)21]-endothelin-1 (0.1 and 1 nmol kg-1, i.v.) evoked similar plasma volume losses to those observed following administration of equimolar doses of endothelin-1. Furthermore, 1 nmol kg-1 [Trp(For)21]-endothelin-l evoked increases in protein extravasation similar to endothelin-l, 1 nmol kg-1.5. The present findings suggest that endothelin- 1 enhances microvascular permeability, in part, via the activation of ETA receptors.

Reduction of capillary permeability in the fructose-induced hypertensive rat.

Impaired insulin transcapillary transport and the subsequent decrease in insulin delivery to target organs have been suggested to play a role in insulin resistance. These defects were studied in fructose-fed rats, an animal model with insulin resistance. For this study, male Sprague-Dawley rats were fed with either a 60% fructose enriched (F) or a standard chow diet (N) for a total of 2, 4, or 8 weeks. Capillary permeability to albumin was assessed at the end of each dietary period by quantifying the extravasation of albumin-bound Evans blue (EB) dye in different organs. Unanesthetized animals were injected with Evans blue dye (20 mg/kg) in the caudal vein 10 min before being killed and EB dye was extracted by formamide from selected organs collected after exsanguination. As expected, rats had an increase in blood pressure upon feeding with fructose at 4 and 8 weeks (F, 149 +/- 3 mm Hg; N, 139 +/- 3 mm Hg; P < .05). Using this technique, we showed a 56% and a 51% reduction in capillary permeability in skeletal muscles at 4 and 8 weeks of fructose feeding, respectively (4 weeks: N, 44.5 +/- 5.0 microg/g of dry tissue; F, 19.8 +/- 4.2 microg/g of dry tissue; P < .01 and 8 weeks: N, 23.3 +/- 3.7 microg/g of dry tissue; F, 11.3 +/- 4.0 microg/g of dry tissue; P < .05). Similar changes were observed at 4 weeks in the thoracic aorta (N, 82.8 +/- 8.8 microg/g of dry tissue; F, 53.0 +/- 5.1 microg/g of dry tissue; P < .02) and skin (N, 36.0 +/- 5.3 microg of dry tissue; F, 15.0 +/- 2.3 microg/g of dry tissue; P < .02) and at 8 weeks in the liver (N, 107.5 +/- 4.3 microg/g of dry tissue; F, 80.9 +/- 3.2 microg/g of dry tissue; P < .01). In conclusion, fructose feeding is accompanied by a significant and selective reduction of Evans blue leakage primarily in skeletal muscle and liver, and transiently in the skin and aorta, consistent with a role for decreased tissue insulin delivery in insulin resistance.

The blood vessel, linchpin of diabetic lesions.

The morbidity and mortality associated with diabetes mellitus are essentially related to the vascular lesions that develop over time in this condition. Both the macrocirculation and microcirculation are involved, and as a consequence, vital organs such as the brain, retina, heart, and kidney and the limbs become damaged. Because microalbuminuria represents the earliest and probably most sensitive indication of endothelial dysfunction in diabetes mellitus, the results of pharmacologic intervention with angiotensin-converting enzyme inhibitors, which treat glomerular hypertension were the first indication of potential beneficial effects in reducing diabetic nephroplasty. The nature of endothelial dysfunction related to diabetes is probably not homogeneous, since microcirculation networks are affected at different periods and with variable intensity. This appears to be the case for the aorta, the heart, segments of the digestive tract, the skin, and the skeletal muscle, the largest consumer of insulin. Although the aorta and large arteries contain a small portion of the total blood volume, their distribution of blood flow (pulse pressure) to peripheral organs may affect endothelial function in the microcirculation. Changes in the structure of conduit arteries, partly responsible for the alteration in compliance characteristics, could well be related to the way these arteries are fed by the vasa vasorum system. This report describes a new in vitro approach to examine capillary permeability in normal and alloxan-induced diabetic rabbits. Preliminary results indicate that the size of terminal arterioles of the vasa vasorum (increased diameter) and the capillary permeability to albumin (markedly enhanced) in this specialized network are profoundly affected in the thoracic aorta obtained from diabetic animals. Albumin extravasation into the interstitial fluid compartment of the aorta is likely to lead to structural and physicochemical changes: in fact, removal of interstitial macromolecules via lymphatic drainage is poor in the blood vessel wall of large arteries. This experimental approach is likely to be useful in the exploration of medications affecting the structure and function of conduit vessels.

Endothelial dysfunction in diabetes mellitus.

In the present study, we examined the pattern of Evan's blue (EB) extravasation over time and we verified the effect of two inhibitors of aldose reductase (sorbinil and ARI 509) as well as aminoguanidine, which modulate nitric oxide (NO) production, on streptozotocin-induced capillary extravasation abnormalities in the upper bronchi, heart, kidney, duodenum, pancreas, skeletal muscle and skin. Albumin extravasation was measured using the EB technique (20 mg/kg). On the third day, a transient decrease in EB leakage was observed in the lung (-49%), heart (-29%) and skeletal muscle (-64%). These early changes in EB were transient, and values returned to normal there after. Later on, EB extravasation was significantly enhanced in the skin (+358, +680, +580, +525 and +365, respectively, at 2, 4, 5, 6 and 7 weeks of diabetes), the duodenum (+101, +160, +92, +124 and +76%), the upper bronchus (+70, +113, +70, +41 and +25%) and the pancreas (+43, +102, +46, +15 and +78%). In the kidney, the increase of EB extravasation was significant at 2 weeks (26%), and from 5 to 7 weeks (+12, +22, +36%). The chronic treatment of diabetic rats with aminoguanidine normalized capillary permeability in most tissues, suggesting that NO is involved in the development of endothelium dysfunction in this streptozotocin-induced diabetic model. Treatment with aldose reductase inhibitors selectively normalized EB extravasation in the kidney.

Antihypertensive drugs and endothelial cell function.

Arterial hypertension is associated with increased capillary permeability, a possible contributor to the vascular remodeling process which could be involved in certain pathological conditions arising from elevated blood pressure. This study evaluated the effects of various antihypertensive drugs on capillary permeability in the normal rat, using Evan's blue dye (EB) as a marker of albumin extravasation. The results reveal that acute injection of certain diuretics (furosemide, indapamide, hydrochlorothiazide) increase while others (amiloride, cicletanine) decrease capillary permeability via stimulation of the cyclooxygenase pathway. 10 day gavage with indapamide, amiloride and cicletanine, as well as angiotensin-converting enzyme (ACE) inhibitor perindopril and calcium channel blockers nifedipine and verapamil decreases capillary permeability, whereas furosemide, hydrochlorothiazide, ACE inhibitor captopril and calcium channel blocker clentiazem do not modify or increase EB extravasation. Hence, selected antihypertensive agents reduce capillary permeability and could therefore have a supplemental protective vascular effect, in addition to their lowering arterial pressure.