l-Arginine Supplementation Alleviates Postprandial Endothelial Dysfunction When Baseline Fasting Plasma Arginine Concentration Is Low: A Randomized Controlled Trial in Healthy Overweight Adults with Cardiometabolic Risk Factors.

BACKGROUND: Vascular endothelial dysfunction, the hallmark of early atherosclerosis, is induced transiently by a high-fat meal. High doses of free l-arginine supplements reduce fasting endothelial dysfunction. OBJECTIVE: We sought to determine the effects of a low dose of a sustained-release (SR) l-arginine supplement on postprandial endothelial function in healthy overweight adults with cardiometabolic risk factors and to investigate whether this effect may vary by baseline arginine status. METHODS: In a randomized, double-blind, 2-period crossover, placebo-controlled trial (4-wk treatment, 4-wk washout), we compared the effects of 1.5 g SR-l-arginine 3 times/d (4.5 g/d) with placebo in 33 healthy overweight adults [body mass index (BMI, in kg/m(2)): 25 to >30] with the hypertriglyceridemic waist (HTW) phenotype [plasma triglycerides > 150 mg/dL; waist circumference > 94 cm (men) or > 80 cm (women)]. The main outcome variable tested was postprandial endothelial function after a high-fat meal (900 kcal), as evaluated by use of flow-mediated dilation (FMD) and Framingham reactive hyperemia index (fRHI), after each treatment. By use of subgroup analysis, we determined whether the effect was related to the baseline plasma arginine concentration. RESULTS: In the total population, the effects of SR-arginine supplementation on postprandial endothelial function were mixed and largely varied with baseline fasting arginine concentration (P-interaction < 0.05). In the lower half of the population (below the median of 78.2 µmol arginine/L plasma), but not the upper half, SR-arginine supplementation attenuated the postprandial decrease in both FMD (29% decrease with SR-arginine compared with 50% decrease with placebo) and fRHI (5% increase with SR-arginine compared with 49% decrease with placebo), resulting in significantly higher mean ± SEM values with SR-arginine (FMD: 4.0% ± 0.40%; fRHI: 0.41 ± 0.069) than placebo (FMD: 2.9% ± 0.31%; fRHI: 0.21 ± 0.060) at the end of the postprandial period (P < 0.05). CONCLUSIONS: Supplementation with low-dose SR-arginine alleviates postprandial endothelial dysfunction in healthy HTW adults when the baseline plasma arginine concentration is relatively low. The benefits of arginine supplementation may be linked to a lower ability to mobilize endogenous arginine for nitric oxide synthesis during a postprandial challenge. This trial was registered at clinicaltrials.gov as NCT02354794.

Evidence for a Specific Diabetic Cardiomyopathy: An Observational Retrospective Echocardiographic Study in 656 Asymptomatic Type 2 Diabetic Patients.

Aim. Our aim was to assess the prevalence of subclinical diabetic cardiomyopathy, occurring among diabetic patients without hypertension or coronary artery disease (CAD). Methods. 656 asymptomatic patients with type 2 diabetes for 14 ± 8 years (359 men, 59.7 ± 8.7 years old, HbA1c 8.7 ± 2.1%) and at least one cardiovascular risk factor had a cardiac echography at rest, a stress cardiac scintigraphy to screen for silent myocardial ischemia (SMI), and, in case of SMI, a coronary angiography to screen for silent CAD. Results. SMI was diagnosed in 206 patients, and 71 of them had CAD. In the 157 patients without hypertension or CAD, left ventricular hypertrophy (LVH: 24.1%) was the most frequent abnormality, followed by left ventricular dilation (8.6%), hypokinesia (5.3%), and systolic dysfunction (3.8%). SMI was independently associated with hypokinesia (odds ratio 14.7 [2.7-81.7], p < 0.01) and systolic dysfunction (OR 114.6 [1.7-7907], p < 0.01), while HbA1c (OR 1.9 [1.1-3.2], p < 0.05) and body mass index (OR 1.6 [1.1-2.4], p < 0.05) were associated with systolic dysfunction. LVH was more prevalent among hypertensive patients and hypokinesia in the patients with CAD. Conclusion. In asymptomatic type 2 diabetic patients, diabetic cardiomyopathy is highly prevalent and is predominantly characterized by LVH. SMI, obesity, and poor glycemic control contribute to structural and functional LV abnormalities.

Noninvasive study of coronary microcirculation response to a cold pressor test.

BACKGROUND: The aims of this study were to noninvasively (i) assess the coronary microcirculation changes in response to a cold pressor test (CPT) in control subjects, nondiabetic obese patients and patients with type 2 diabetes and (ii) investigate the response of the coronary microcirculation in patients with diabetes according to the presence or the absence of silent myocardial ischaemia (SMI), asymptomatic coronary stenosis (CS) and left ventricle hypertrophy (LVH). METHODS: The mean left anterior descending coronary flow velocity (mCFV) was measured using transthoracic Doppler before and after a CPT in 16 control subjects, 11 obese and 66 asymptomatic diabetic patients with a high cardiovascular risk. Patients with diabetes were screened for SMI using stress myocardial scintigraphy and/or echocardiography. A coronary angiography was performed in those with SMI. RESULTS: At baseline, pressure-rate product (PRP) was correlated with mCFV (r = 0.23; P < 0.05) and left ventricle mass (r = 0.26; P < 0.05) in the whole population. Changes in PRP and mCFV during CPT were correlated with controls (r = 0.58, P < 0.05), obese (r = 0.75, P < 0.01) and diabetic patients without CS (r = 0.56, P < 0.0001) or without LVH (r = 0.63, P < 0.05) but not in diabetic patients with CS or with LVH. In patients with diabetes, SMI was associated with mCFV changes, independent of other parameters (P < 0.05). CONCLUSION: Transthoracic coronary Doppler allows noninvasive study of changes in the coronary microcirculation during CPT. In asymptomatic patients with type 2 diabetes, this method showed that SMI was associated with mCFV changes during CPT and the presence of CS or LVH was associated with a mismatch between coronary microcirculation and myocardial oxygen demand.

Flow-mediated-paradoxical vasoconstriction is independently associated with asymptomatic myocardial ischemia and coronary artery disease in type 2 diabetic patients.

BACKGROUND: To investigate whether flow-mediated dilation (FMD) impairment, which precedes overt atherosclerosis, is associated with silent myocardial ischemia (SMI) and asymptomatic coronary artery disease (CAD) in type 2 diabetes. METHODS: Forearm FMD was measured by ultrasonography in 25 healthy control, 30 non-diabetic overweight or obese patients and 118 asymptomatic type 2 diabetic patients with a high cardiovascular risk profile. SMI (abnormal stress myocardial scintiscan and/or stress dobutamine echocardiogram) and CAD (coronary angiography in the patients with SMI) were assessed in the diabetic cohort. RESULTS: FMD was lower in diabetic patients (median 0.61% (upper limits of first and third quartiles -1.22;3.2)) than in healthy controls (3.95% (1.43;5.25), p < 0.01) and overweight/obese patients (4.25% (1.74;5.56), p < 0.01). SMI was present in 60 diabetic patients, including 21 subjects with CAD. FMD was lower in patients with SMI than in those without (0.12% (-2.3;1.58) vs 1.64% (0;3.69), p < 0.01), with a higher prevalence of paradoxical vasoconstriction (50.0% vs 29.3%, p < 0.05). FMD was also lower in patients with than without CAD (-1.22% (-2.5;1) vs 1.13% (-0.4;3.28), p < 0.01; paradoxical vasoconstriction 61.9% vs 34.4%, p < 0.05). Logistic regression analyses considering the parameters predicting SMI or CAD in univariate analyses with a p value <0.10 showed that paradoxical vasoconstriction (odds ratio 2.7 [95% confidence interval 1.2-5.9], p < 0.05) and nephropathy (OR 2.6 [1.2-5.7], p < 0.05) were independently associated with SMI; and only paradoxical vasoconstriction (OR 3.1 [1.2-8.2], p < 0.05) with CAD. The negative predictive value of paradoxical vasoconstriction to detect CAD was 88.7%. CONCLUSIONS: In diabetic patients, FMD was independently associated with SMI and asymptomatic CAD. TRIAL REGISTRATION: Trial registration number NCT00685984.

Epo deficiency alters cardiac adaptation to chronic hypoxia.

The involvement of erythropoietin in cardiac adaptation to acute and chronic (CHx) hypoxia was investigated in erythropoietin deficient transgenic (Epo-TAg(h)) and wild-type (WT) mice. Left (LV) and right ventricular functions were assessed by echocardiography and hemodynamics. HIF-1α, VEGF and Epo pathways were explored through RT-PCR, ELISA, Western blot and immunocytochemistry. Epo gene and protein were expressed in cardiomyocytes of WT mice in normoxia and hypoxia. Increase in blood hemoglobin, angiogenesis and functional cardiac adaptation occurred in CHx in WT mice, allowing a normal oxygen delivery (O2T). Epo deficiency induced LV hypertrophy, increased cardiac output (CO) and angiogenesis, but O2T remained lower than in WT mice. In CHx Epo-TAg(h) mice, LV hypertrophy, CO and O2T decreased. HIF-1α and Epo receptor pathways were depressed, suggesting that Epo-TAg(h) mice could not adapt to CHx despite activation of cardioprotective pathways (increased P-STAT-5/STAT-5). HIF/Epo pathway is activated in the heart of WT mice in hypoxia. Chronic hypoxia induced cardiac adaptive responses that were altered with Epo deficiency, failing to maintain oxygen delivery to tissues.

Bosentan effects in hypoxic pulmonary vasoconstriction: Preliminary study in subjects with or without high altitude pulmonary edema-history.

Hypoxia-induced pulmonary vasoconstriction in patients with a medical history of high-altitude pulmonary edema (HAPE) may involve activation of the endothelin-1 (ET-1) pathway. We, therefore, compared the effect of the ETA/ETB receptor antagonist, bosentan, on pulmonary artery systolic pressure (PASP) in healthy subjects with (HS: HAPE subjects, n=5) or without a HAPE-history (CS: Control subjects, n=10). A double-blind, placebo-controlled, randomized, crossover design was performed in order to study the effects on PASP of a single oral dose of bosentan (250 mg) after 90 min exposure to normobaric hypoxia (FiO(2) =0.12). In normoxia, PASP, evaluated by echocardiography, was 23.4±2.7 mmHg in CS and 28±5.8 mmHg in HS (NS). During the placebo period, hypoxia induced a significant decrease in SaO(2), PaO(2) and PCO(2) and increase in pH in both CS and HS. Pulmonary arterial systolic pressure was also significantly increased (+8.5±5.0 mmHg in CS; +13.4±3.1 mmHg in HS) and reached significantly higher levels in HS than in CS (P=0.02). Bosentan significantly but similarly blunted the hypoxia-induced increase in PASP in both CS (Bosentan: 27.0±3.3 mmHg; placebo: 32.1±3.5 mmHg; P<0.01) and HS (Bosentan: 35.0±2.9 mmHg; placebo: 41.4±7.6 mmHg; P<0.05), (CS 5.2±5.3 vs. HS -6.4±5.2 mmHg, NS). Bosentan did not have a major effect on the hypoxia-induced changes in blood gas, or on cardiac output (CO) and systemic blood pressure (SBP), which were not modified by hypoxia. Plasma ET-1 in hypoxia during the bosentan period was 2.8 times higher than during for both CS and HS. A single oral dose of bosentan similarly blunted the hypoxia-induced increase in PASP both in healthy and HAPE-susceptible subjects, without altering CO or SBP.

Inhibition of vascular smooth muscle cell proliferation and migration in vitro and neointimal hyperplasia in vivo by adenoviral-mediated atrial natriuretic peptide delivery.

BACKGROUND: Vascular smooth muscle cell (VSMC) proliferation and migration are important components of the remodeling process in atherosclerosis or following angioplasty. Atrial natriuretic peptide (ANP) inhibits the growth of VSMCs in vitro but this effect has not been proven in vivo. In the present study, we examined the effects of local overexpression of ANP following gene transfer on in vitro VSMC proliferation and migration and in vivo neointimal formation in a rat carotid artery model of vascular injury. METHODS: ANP gene transfer was performed using a recombinant adenovirus containing the ANP cDNA controlled by the Rous sarcoma virus (RSV) long terminal repeat (Ad-RSV-ANP). A recombinant adenovirus expressing the RSV-controlled ß-galactosidase gene (Ad-RSV-ß-gal) was used as the control. Rat VSMC culture was used for in vitro studies. In the in vivo experiments, carotid arteries were analyzed after balloon injury and local infusion of the viral solution. RESULTS: VSMCs transfected by Ad-RSV-ANP produced a significant amount of ANP detected by immunoreactive assay and accumulated about 6.5 times more cGMP than the viral control. VSMC proliferation stimulated with 10% fetal calf serum was reduced by 31% and migration by 25%. Fourteen days after injury, neointimal formation and the intima/media ratio were reduced by 25% and 28%, respectively, in the Ad-RSV-ANP-treated group compared to the control group. CONCLUSIONS: The present study demonstrates the efficacy of recombinant adenovirus Ad-RSV-ANP with respect to inhibiting rat VSMC proliferation and migration. Our findings also provide evidence that ANP is implicated in the modulation of vascular remodeling following endothelial injury.

Amebic liver abscess, extensive thrombosis, and patent cardiac foramen ovale.

Extensive venous thrombosis is usually seen postmortem in amebic liver abscess because of its dismal prognosis. Herein, we describe amebic liver abscess, whose late diagnosis led to multiple deep thromboses, pulmonary embolism, and right atrial thrombosis, in this patient with patent foramen ovale.

Pulmonary pressure and cardiac function in chronic mountain sickness patients.

BACKGROUND: Chronic mountain sickness (CMS) is characterized by a loss of adaptation to hypoxia in high-altitude (HA) dwellers. Chronic hypoxemia, excessive erythrocytosis and frequently pulmonary hypertension (PH), which may lead to cardiac failure, develop in patients. We sought to assess the determinants of cardiac function in CMS patients with hypoxia-induced PH. METHODS: Fifteen healthy men living at sea level (SL) were compared to 15 healthy men living at HA and 55 patients with CMS from Cerro de Pasco, Peru (altitude, 4,300 m). Pulmonary pressures and cardiac function were estimated by echocardiography. RESULTS: None of the subjects had overt cardiac failure symptoms. CMS patients exhibited elevated mean pulmonary pressures as assessed by high-tricuspid pressure gradients (CMS patients, 34 +/- 10 mm Hg; HA subjects, 25 +/- 4 mm Hg [p = 0.002]; and SL subjects, 19 +/- 3 mm Hg [p < 0.001]). They also showed right ventricular (RV) dilation (mean end-diastolic RV area: CMS patients, 17 +/- 2 cm(2); HA subjects, 13 +/- 2 cm(2); SL subjects, 12 +/- 2 cm(2); p < 0.001) but did not display impaired systolic ventricular function. However, the RV Tei index was increased in CMS and HA subjects (CMS patients, 0.56 +/- 0.15; HA subjects, 0.52 +/- 0.12; SL subjects, 0.21 +/- 0.12; p < 0.001). CONCLUSION: Despite obvious pulmonary arterial hypertension and right heart dilation, CMS patients did not show any symptom or echocardiographic parameter of heart failure. TRIAL REGISTRATION: ClinicalTrials.gov. Identifier: NCT00424970.

Acetazolamide for Monge's disease: efficiency and tolerance of 6-month treatment.

RATIONALE: Monge's disease is characterized by an excessive erythrocytosis, frequently associated with pulmonary hypertension, in high-altitude dwellers. It has a considerable impact on public health in high-altitude regions. A preliminary study demonstrated the efficiency of acetazolamide (Acz) (250 mg/d for 3 wk) in reducing serum erythropoietin and hematocrit. OBJECTIVES: Evaluate the efficacy and tolerance of a 6-month treatment with 250 mg Acz that could be chronically implemented and its effects on pulmonary artery pressure and cardiac function. METHODS: A two-phase study was performed in patients (hematocrit > or = 63%) from Cerro de Pasco, Peru (4,300 m). First phase: a double-blind, placebo-controlled study in 55 patients who received a single dose of either 250 mg Acz (n = 40) or placebo (n = 15) by daily oral administration for 12 weeks. Second phase (open label): after a 4-week washout period, all patients received 250 mg Acz for 12 weeks. Hematocrit, blood gases, clinical outcome, and pulmonary artery circulation were evaluated. MEASUREMENTS AND MAIN RESULTS: First phase: Acz decreased by 44% the number of polycythemic subjects (P = 0.02), decreased hematocrit from 69 to 64% (P < 0.001), and increased arterial O(2) pressure from 42 to 45 mm Hg (P < 0.001). No severe adverse effect or hypokalemia was recorded. The second phase reproduced the effects observed during the first phase, without cumulative effects on hematocrit. A 4-week washout restored basal hematocrit. Only patients who received Acz for 6 months showed a clear reduction in pulmonary vascular resistance. CONCLUSIONS: Acz reduces erythrocytosis and improves pulmonary circulation in Monge's disease without adverse effects. Its implementation as a chronic treatment for this disease appears efficient and safe.

A modified Cockcroft-Gault formula taking into account the body surface area gives a more accurate estimation of the glomerular filtration rate.

We sought to validate the improvement by adjustment for body surface area (BSA) of the accuracy of the original Cockcroft-Gault equation to estimate glomerular filtration rate (GFR), in a prospective cross-sectional study of 269 European patients with chronic kidney disease (CKD). We compared 3 methods: original Cockcroft-Gault equation, modified Cockcroft-Gault formula adjusted for BSA and abbreviated Modification of Diet in Renal Disease (MDRD) equation, using inulin clearance. Statistical analyses comprised repeated-measures analysis of variance (ANOVA), determination of the Pearson coefficient of correlation and a Bland-Altman concordance study. The ability of the GFR estimates to properly categorize patients in K/DOQI stages of CKD was also examined. Inulin clearance differed significantly from the standard Cockcroft-Gault method (ANOVA, p<0.001) and the abbreviated MDRD method (ANOVA, p<0.001) but not from the BSA-modified Cockcroft-Gault formula. Inulin clearance correlated better with the BSA-modified Cockcroft-Gault formula (r=0.88) and abbreviated MDRD equation (r=0.87) than with the standard Cockcroft-Gault equation (r=0.82). In concordance studies, bias was far smaller with the BSA-modified Cockcroft-Gault formula (mean bias -1.75 ml/min), than with the standard Cockcroft-Gault equation (mean bias -4.72 ml/min). The bias of the abbreviated MDRD was larger (mean bias +6.24 ml/min). Only patients with CKD stage 1 were better categorized with the BSA-modified Cockcroft-Gault formula and with the standard Cockcroft-Gault estimate than with the abbreviated MDRD equation. We conclude that adjustment for body surface area improves accuracy of the original Cockcroft-Gault equation.

Impaired coronary endothelium-dependent vasodilation is associated with microalbuminuria in patients with type 2 diabetes and angiographically normal coronary arteries.

OBJECTIVE: Microalbuminuria and impaired endothelium-dependent vasodilation are both predictors for cardiac events in patients with type 2 diabetes. The aim of the study was to evaluate whether microalbuminuria correlated with coronary endothelium-dependent vasodilation. RESEARCH DESIGN AND METHODS: We evaluated 84 patients (47 men, mean age 50.5 +/- 5.9 years) with type 2 diabetes for 9.4 +/- 3.4 years, without angiographic coronary stenosis and without major cardiovascular risk factors or other confounding factors, for endothelium investigation. Quantitative coronary angiography was used to assess coronary artery response to cold pressor testing, used to assess endothelium-dependent vasodilation, and to isosorbide dinitrate (endothelium-independent vasodilation). RESULTS: Endothelium-dependent vasodilation differed in the patients with and without microalbuminuria (changes in coronary artery diameter during cold pressor testing: -15.0 +/- 1.9% vs. -10.2 +/- 1.3%, respectively, P < 0.05) and correlated with urinary albumin excretion rate (r = -0.39, P = 0.003), diastolic blood pressure (r = 0.29, P < 0.01), and left ventricular mass index (r = -0.24, P < 0.05). Independent predictors for endothelium-dependent vasodilation were urinary albumin excretion rate (beta -0.04 [95% CI -0.07 to -0.01], P < 0.005) and left ventricular mass index (-0.26 [-0.49 to -0.05], P < 0.05). Endothelium-independent vasodilation was similar in both groups. CONCLUSIONS: Type 2 diabetic patients with microalbuminuria have a more severely impaired coronary endothelium-dependent vasodilation than those with normoalbuminuria. These data suggest a common pathophysiological process for both coronary vasomotor abnormalities and microalbuminuria.

Cardiovascular outcome of patients with abnormal coronary vasomotion and normal coronary arteriography is worse in type 2 diabetes mellitus than in arterial hypertension: a 10 year follow-up study.

Diabetes and arterial hypertension are major cardiovascular risk factors. Coronary endothelial dysfunction is frequently observed in diabetic and hypertensive patients. This study was designed to compare cardiovascular outcome of hypertensive (HT) and type 2 diabetic patients (D2) with angiographically normal coronary arteries on the basis of their epicardial coronary endothelial function. Coronary reactivity assessment by cold-pressor test (CPT) using quantitative coronary angiography was achieved in 65 HT (45 males, 20 females) aged 51.9+/-7.6 years, and in 59 D2 (32 males, 27 females) aged 48.9+/-7.3 years, with angiographically normal coronary arteries and without other major coronary risk factor. Cardiovascular events (CVE) were recorded with a mean follow-up of 108+/-15 months in HT, and 113+/-10 months in D2. During CPT, in HT coronary artery dilation occurred in 10.8% of the patients, no change in 21.5%, and constriction in 67.7%. In D2, dilation occurred in 3.4% of the patients, no change in 18.6%, and constriction in 78.0%. During follow-up, in HT there were nine CVE in 6/65 patients (9.2%), all in the 6/44 (13.6%) patients with coronary artery constriction. In D2, there were 18 CVE in 16/59 patients (27.1%, P<0.01 versus HT), with 17 CVE in the 15/46 patients with coronary artery constriction, and one CVE in the 1/13 patients without constriction (32.6% versus 7.7%). In patients with coronary artery constriction, CVE were more frequent in D2 than in HT (P<0.05). Last, CVE were more severe and occurred earlier in D2 than in HT. In conclusion, epicardial coronary endothelial dysfunction is predictive of long-term CVE in HT and D2 with angiographically normal coronary arteries. Cardiovascular outcome of patients with coronary constriction is worse in D2 than in HT. At the opposite, patients without constriction have good cardiovascular prognosis in both subgroups.

Sildenafil inhibits altitude-induced hypoxemia and pulmonary hypertension.

Exposure to high altitude induces pulmonary hypertension that may lead to life-threatening conditions. In a randomized, double-blind, placebo-controlled study, the effects of oral sildenafil on altitude-induced pulmonary hypertension and gas exchange in normal subjects were examined. Twelve subjects (sildenafil [SIL] n = 6; placebo [PLA] n = 6) were exposed for 6 days at 4,350 m. Treatment (3 x 40 mg/day) was started 6 to 8 hours after arrival from sea level to high altitude and maintained for 6 days. Systolic pulmonary artery pressure (echocardiography) increased at high altitude before treatment (+29% versus sea level, p < 0.01), then normalized in SIL (-6% versus sea level, NS) and remained elevated in PLA (+21% versus sea level, p < 0.05). Pulmonary acceleration time decreased by 27% in PLA versus 6% in SIL (p < 0.01). Cardiac output and systemic blood pressures increased at high altitude then decreased similarly in both groups. Pa(O(2)) was higher and alveolar-arterial difference in O(2) lower in SIL than in PLA at rest and exercise (p < 0.05). The altitude-induced decrease in maximal O(2) consumption was smaller in SIL than in PLA (p < 0.05). Sildenafil protects against the development of altitude-induced pulmonary hypertension and improves gas exchange, limiting the altitude-induced hypoxemia and decrease in exercise performance.

Hypoxia upregulates VEGF expression in alveolar epithelial cells in vitro and in vivo.

We investigated regulation of vascular endothelial growth factor (VEGF) expression by hypoxia in cultured and freshly isolated rat alveolar epithelial cells (AEC). In vitro, hypoxia increased VEGF mRNA and protein levels, with maximal stimulation at 0% O2 for 18 h. A similar upregulation of VEGF expression was found in alveolar epithelial type II (ATII) cells freshly isolated from rats exposed to 8% O2 for 24 h. In vitro, hypoxia-induced upregulation of VEGF mRNA was due to an increase in transcription, rather than an increase in RNA stability, inasmuch as the half-life of VEGF mRNA was unchanged. Upregulation of VEGF mRNA by hypoxia was mimicked by CoCl2 and desferrioxamine in normoxic AEC and was not prevented by inhibitors of reactive oxygen species, suggesting that hypoxic VEGF regulation involved an O2-dependent protein that requires ferrous ions but is independent of reactive oxygen species generation. In polarized ATII cells, VEGF protein was secreted at the apical and basolateral sides. Similarly, in rats, VEGF was secreted in bronchoalveolar lavage fluid. Hypoxia induced a twofold increase in VEGF protein at the apical side of ATII cells in culture and in bronchoalveolar lavage fluid. These findings suggest that release of VEGF synthesized by AEC may target not only endothelial cells but also other alveolar cells, including macrophages and epithelial cells.