Safe and Successful Surgical Outcome in Persons with Hemophilia A with and without Inhibitors Treated with Emicizumab: A Large, Single Center, Real-World Experience.

Emicizumab is a humanized recombinant bispecific antibody, bridging together activated factor IX (FIXa) and factor X (FX), thus mimicking the activity of FVIII in vivo. Emicizumab is designed for long-term prophylaxis in patients with severe hemophilia A with and without inhibitors. This approach provides constant protection, with significant reduction in bleeding rate and improved quality of life. However, protection provided by emicizumab is not absolute, and clotting factor concentrates (FVIII, rFVIIa, aPCC) may be necessary for post-traumatic bleeding or surgery, with a potential thrombotic risk or difficulty in preventing bleeding. Real world evidence is still scanty, especially for managing major surgery. In this study, 75 surgeries were managed in 28 patients (27 major procedures in 15 patients and 48 minor procedures in 20 patients. In 17 patients without inhibitors, 30 minor surgeries were carried out by using FVIII in 5, with only a bleeding event, which was successfully treated with FVIII concentrate. Six major surgeries were uneventfully performed with FVIII concentrate. Eleven PWHA and high-titer inhibitors underwent 39 surgical procedures (18 minor and 21 major surgeries). Minor surgeries were mostly performed without prophylaxis with rFVIIa, with only a single bleeding complication. All 21 major surgeries were covered with a homogeneous protocol using rFVIIa. In four instances, bleeding complications occurred, treated with rFVIIa. Of them, a single patient only failed to respond and died because of an uncontrollable bleeding from a large ruptured retroperitoneal pseudotumor. Surgery in patients with emicizumab can be safely carried out with the use of appropriate replacement therapy protocols.

Abnormal coronary reserve and left ventricular wall motion during cold pressor test in patients with previous left ventricular ballooning syndrome.

AIMS: To investigate whether and how cold pressor test (CPT) could affect myocardial perfusion and left ventricular (LV) function in patients with previous LV ballooning syndrome (LVBS). METHODS AND RESULTS: Cold pressor test (3 min hand immersion in ice-water) was performed in 17 women with previous LVBS and in 7 age- and risk factor-matched women with chest pain and normal coronary arteries. At baseline and peak CPT, global and regional LV function, and myocardial perfusion were quantitatively assessed by real-time three-dimensional echocardiography (RT3DE) and myocardial contrast (SonoVue, Bracco) 2D echocardiography (MCE), respectively (Philips iE33 machine, X3-1 and S5-1 probes). Data were analysed off-line (QLab 6.0 software). Peripheral venous catecholamines were assayed by high performance liquid chromatography with electrochemical detection. Cold pressor test induced similar haemodynamic changes and catecholamine increase in controls and LVBS patients. Left ventricular ejection fraction decreased and transient new mid-ventricular and apical motion abnormalities developed in LVBS patients only (quantitative RT3D analysis), without corresponding perfusion defects (MCE). At peak CPT, coronary blood flow and velocity increased (quantitative MCE analysis) in control subjects only. CONCLUSION: Cold pressor test induced LV wall motion abnormalities unmatched to regional coronary flow reduction in LVBS patients only. The reduced coronary reserve in response to CPT suggests microvascular dysfunction in LVBS patients.

T-Lymphocyte-Based Renin Angiotensin System in Obesity.

BACKGROUND: Obesity can be associated with increased cardio-metabolic risk, but some subjects with obesity do not show metabolic impairment and escape this association. Low-grade inflammation (i.e., high sensitivity C-reactive protein [hsCRP] > 3 mg/dL) is associated with high cardiovascular risk in obesity. We investigated renin-angiotensin system (RAS) activity in cultured circulating T-cells in subjects with obesity with and without angiotensin II (Ang II) stimulation in the presence or absence of low-grade inflammation. MATERIALS AND METHODS: We studied 18 subjects with obesity and 10 healthy subjects. After T-lymphocyte isolation, T-cell mRNAs for angiotensin converting enzyme (ACE) and AT1-receptor were quantified by reverse transcription polymerase chain reaction at baseline and after Ang II stimulation. hsCRP, plasma renin and ACE activity in the cell pellet and supernatant and Ang II T-cell content were also measured. RESULTS: T-cell RAS in subjects with obesity with low-grade inflammation was more activated than in subjects with obesity without low-grade inflammation. The increase in RAS activation occurred both at baseline and after Ang II stimulation. Similarly, the release of ACE activity in the supernatant was significantly higher in subjects with obesity with hsCRP > 3 mg/dL than in subjects with hsCRP < 3 mg/dL and controls. CONCLUSIONS: Circulating T-cell based RAS is activated in subjects with obesity independently of low-grade inflammation that amplifies the T-cell RAS response to Ang II stimulation.

Impaired angiotensin II-extracellular signal-regulated kinase signaling in failing human ventricular myocytes.

Angiotensin II was reported to induce insulin-like growth factor-I and endothelin-1 gene expression and peptide release by ventricular cardiomyocytes. However, the progression from cardiac hypertrophy to failure in humans is characterized by a reduced myocyte expression of insulin-like growth factor-I and endothelin-1, notwithstanding the enhanced cardiac generation of angiotensin II. In the present study we investigated the functional status of the signaling pathways responsible for angiotensin II-induced endothelin-1 and insulin-like growth factor-I formation in human ventricular myocytes isolated from patients with dilated (n = 19) or ischemic (n = 14) cardiomyopathy and nonfailing donor hearts (n = 6).In human nonfailing ventricular myocytes, angiotensin II (100 nmol/l) induced insulin-like growth factor-I and endothelin-1 gene expression, and peptide release was mediated by extracellular signal-regulated kinase activation and inhibited by extracellular signal-regulated kinase antagonism (PD98059, 30 micromol/l), endothelin-1 formation being partially reduced also by c-Jun N-terminal kinase inhibition (SP600125, 10 micromol/l); insulin-like growth factor-I and endothelin-1 formations were unaffected by the inhibition of p38 mitogen-activated protein kinase (SB203580, 10 micromol/l) and Janus tyrosine kinase 2 (AG490, 10 micromol/l). In failing myocytes, angiotensin II failed to induce insulin-like growth factor-I and endothelin-1 formation; angiotensin II-induced extracellular signal-regulated kinase activation was significantly impaired (-88% vs. controls) although c-Jun NH2-terminal kinase activation was preserved. The impaired extracellular signal-regulated kinase phosphorylation in failing myocytes was associated with increased myocyte levels of mitogen-activated protein kinase phosphatases.Therefore, the altered growth factor production in failing myocytes is associated with a significant derangement in intracellular signaling.

Angiotensin II upregulates renin-angiotensin system in human isolated T lymphocytes.

This study was aimed at investigating the effects of Angiotensin (Ang) II stimulation on T lymphocytes mRNA expression of angiotensinogen (AGTN), angiotensin-converting enzyme (ACE) and AT1-receptor (R) and on ACE activity and Ang II content. The effects of Ang II stimulus were studied in lipopolysaccharide (LPS)-stimulated or not stimulated lymphocytes. mRNA expression for interferon-gamma (INF-gamma) was also studied to investigate whether a link between lymphocyte RAS and immunological function might occur. mRNAs for AGTN, ACE and AT1-R were obtained from peripheral blood of 18 healthy subjects and were quantified by real time quantitative transcriptase-polymerase chain reaction (PCR). ACE activity was assayed in cell pellets and supernatants by measuring the hippuric acid formation by high performance liquid chromatography (HPLC) and Ang II cell content was measured by radioimmunoassay (RIA) after HPLC separation. All determination were performed under baseline conditions and after the addition of 10(e- 13) M Ang II to LPS-stimulated or unstimulated lymphocytes. Ang II caused a significant upregulation of T subset lymphocytes gene expression of ACE and AT1-R and of INF gamma, and a marked increase in ACE activity and cell Ang II concentration. AGTN gene was never expressed. All these effects were further enhanced in T lymphocytes presitmulated by LPS and completely inhibited by Irbesartan. Our findings strongly support the evidence of a positive Ang II driven autocrine loop that upregulates cell RAS of isolated lymphocytes and activates the immuno response. The immuno-potentiating effect of Ang II, specifically shown in T subset, can be deleterious when local RAS are disregulated as in cardiovascular atherosclerotic disease.

Persistent and selective upregulation of renin-angiotensin system in circulating T lymphocytes in unstable angina.

INTRODUCTION: Unstable angina is associated with an acute systemic inflammatory reaction and circulating T lymphocytes are activated. We investigated whether in unstable angina with marked immune system activation a selective upregulation of the circulating T-cell renin-angiotensin system, modulated by angiotensin II, could occur. METHODS: We studied 13 unstable angina patients, 10 patients with stable angina and 10 healthy subjects. After T-lymphocyte isolation, mRNAs for angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor (AT1-R) were quantified at baseline and after angiotensin II stimulation. ACE activity in cell pellet and supernatant and angiotensin II cell content were measured. RESULTS: Plasma renin activity was similar in controls, stable and unstable angina patients. At baseline ACE and AT1-R mRNA levels were higher ( P<0.05) in T cells from unstable angina patients than in T cells from stable angina patients and controls, and further increased after angiotensin II addition to cultured T cells. ACE activity of unstable angina T cells was significantly higher than that of T cells from controls and stable angina patients. Only in T cells from unstable angina patients did angiotensin II stimulation cause the almost complete release of ACE activity in the supernatant. CONCLUSIONS: The circulating T-cell-based renin-angiotensin system from unstable angina patients was selectively upregulated. In vivo unstable angina T cells could locally increase angiotensin II concentration in tissues where they migrate independently of the circulating renin-angiotensin system.

Perioperative Levels of Adiponectin and Oxidative Stress in Patients Undergoing Laparoscopic Abdominal Surgery for Cancer.

BACKGROUND: Low circulating levels of adiponectin are associated with the occurrence of infection after surgery in patients with cancer. Data are lacking on whether surgical stress is associated with a reduction in circulating levels of adiponectin. Furthermore, the relationship between oxidative stress and postoperative complications has not been investigated. OBJECTIVE: The aim of this study was to evaluate the pre-, intra-, and postoperative levels of adiponectin in patients who underwent major abdominal surgery for malignancy and their association with postoperative complications. METHODS: An observational, prospective, single-center study was conducted in patients undergoing abdominal surgery for cancer. Circulating levels of adiponectin and of two biomarkers of oxidative stress were measured preoperatively, at the end of surgery, 24 and 48 hours after surgery. Patients were divided into two groups: complicated (CL+) and uncomplicated (CL-), according to the Clavien-Dindo classification. Temporal patterns of adiponectin and markers of oxidative stress were followed at different time points. RESULTS: Twelve patients were enrolled, seven with postoperative complications (CL+) and five without (CL-). The preoperative median levels of adiponectin were statistically different between CL+ and CL- groups (3.2 µg/ml vs 10.9 µg/ml; p=0.03). Levels of preoperative adiponectin were inversely related to the severity of postoperative complications (Rho= -0.68; p= 0.02). Pre-, intra- and postoperative levels of oxidative stress products were not statistically different between the two groups. Adiponectin levels decreased during surgery in both groups, while those of oxidative stress tended to increase. CONCLUSIONS: Preoperative adiponectin levels correlate with postoperative complications after cancer surgery.

Hyperglycemia activates JAK2 signaling pathway in human failing myocytes via angiotensin II-mediated oxidative stress.

Hyperglycemia was reported to enhance angiotensin (Ang) II generation in rat cardiomyocytes, and Ang II inhibition reduces cardiovascular morbidity and mortality in diabetic patients. In diabetic patients, the enhanced activation of intracellular pathways related with myocyte hypertrophy and gene expression might enhance the progression of cardiac damage. Therefore, we investigated the effects of glucose on Ang II-mediated activation of Janus-activated kinase (JAK)-2, a tyrosine kinase related with myocyte hypertrophy and cytokine and fibrogenetic growth factor overexpression, in ventricular myocytes isolated from nonfailing human hearts (n = 5) and failing human hearts (n = 8). In nonfailing myocytes, JAK2 phosphorylation was enhanced by Ang II only in the presence of high glucose (25 mmol/l) via Ang II type I (AT1) receptors (+79% vs. normal glucose, P < 0.05). JAK2 activation was prevented by inhibitors of reactive oxygen species (ROS) generation (diphenyleneiodonium [DPI], tiron, and apocynin). In myocytes isolated from failing hearts, JAK2 phosphorylation was enhanced by high glucose alone (+107%, P < 0.05). High glucose-induced JAK2 activation was blunted by both ACE inhibition (100 nmol/l ramipril) and AT1 antagonism (1 mumol/l valsartan), thus revealing that the effects are mediated by autocrine Ang II production. Inhibition of ROS generation also prevented high glucose-induced JAK2 phosphorylation. In conclusion, in human nonfailing myocytes, high glucose allows Ang II to activate JAK2 signaling, whereas in failing myocytes, hyperglycemia alone is able to induce Ang II generation, which in turn activates JAK2 via enhanced oxidative stress.

Immunomediated and ischemia-independent inflammation of coronary microvessels in unstable angina.

This study investigated whether the myocardium is involved in the acute inflammatory reaction associated with bursts of unstable angina (UA). We looked for the presence of activated DR+ inflammatory cells and the expression patterns, localization, and immunostaining identification of genes for cytokines (IL-1beta, TNF-alpha, IL-6, and IFN-gamma), MCP-1, and iNOS in the left ventricle biopsies from 2-vessel disease anginal patients, 24 with UA and 12 with stable angina (SA), who underwent coronary bypass surgery. Biopsy specimens from 6 patients with mitral stenosis who underwent valve replacement were examined as control hearts (CHs). Plasma levels of IL-2 soluble receptor (sIL-2R) were measured as a marker of systemic immune reaction. In CHs, DR+ cells were undetectable, and cytokine and iNOS mRNA expression were negligible. UA patients had higher sIL-2R levels than SA patients (P<0.01), and their biopsy specimens showed both numerous DR+ cells identified as lymphocytes, macrophages, endothelial cells, and elevated expression levels of cytokine and iNOS genes (from 2.4- to 6.1-fold vs SA; P<0.01). Cytokine and iNOS genes and proteins were localized in endothelial cells without involvement of myocytes. IL-1beta and MCP-1 mRNAs were nearly undetectable. No significant differences were found in the number of DR+ cells, levels of cytokine, and iNOS genes between potentially ischemic and nonischemic left ventricle areas. In SA specimens, DR+ cells were very rare and only mRNAs for TNF-alpha and iNOS genes were overexpressed versus CHs. These results indicated that an acute immunomediated inflammatory reaction, essentially involving coronary microvessels, is demonstrable in UA patients.

Cardiac angiotensin II participates in coronary microvessel inflammation of unstable angina and strengthens the immunomediated component.

Angiotensin (Ang) II is now recognized to be a mediator of a wide variety of inflammatory processes. This study investigated renin-angiotensin system (RAS) components and a number of inflammatory mediators in left ventricular biopsies from 2-vessel disease unstable angina (UA) (n=43) and stable angina (SA) (n=15) patients undergoing coronary bypass surgery. Biopsy samples from 6 patients undergoing valve replacement for mitral stenosis served as controls. UA patients were randomly assigned to angiotensin-converting enzyme (ACE)-inhibitor (ramipril), AT1 antagonist (valsartan), or placebo and treated during the 5 days preceding coronary bypass surgery, performed from 6 to 9 days after coronary angiography. During coronary angiography coronary blood flow was measured and samples were obtained from aorta and coronary sinus for determination of Ang I and Ang II gradients. The hearts of UA patients produced Ang II in a greater amount than in SA patients (P<0.01). UA biopsy samples showed numerous DR+ cells, identified as lymphocytes, macrophages, and endothelial cells. Reverse-transcriptase polymerase chain reaction showed overexpression of AGTN, ACE, and AT1-R genes, as well as upregulation of TNF-alpha, IL-6, IFN-gamma, and iNOS genes (P<0.01), with no differences between nonischemic and potentially ischemic areas. AGTN, ACE, and cytokine genes were mainly localized on endothelial cells. Ramipril and valsartan markedly decreased the expression levels of TNF-alpha, IL-6, and iNOS, and, to a lesser extent, of IFN-gamma genes, but did not affect the number of DR+ cells, with no significant difference between the 2 treatments. These results show that locally generated Ang II amplifies the immunomediated inflammatory process of coronary microvessels occurring in unstable angina.

Exaggerated myocardial oxLDL amount and LOX-1 receptor over-expression associated with coronary microvessel inflammation in unstable angina.

The pathophysiological relationship between coronary atherosclerosis and coronary microvessels remains undefined and the specific causative role of oxidatively modified low density lipoprotein (oxLDL) in human atherosclerosis is debated. The purposes of this study are to investigate whether coronary microvessels are involved in coronary atherosclerosis and whether increased myocardial oxLDL amount can be associated with coronary microvessel inflammation. A combination of immunohistochemical, RT-PCR and real-time PCR studies performed on myocardial biopsy specimens from patients with mitral stenosis (control hearts, CHs) and from unstable and stable angina patients (UAP and SAP), demonstrated that myocardial oxLDL was associated with a chronic low-grade inflammation in SAP and with a severe high grade inflammation in UAP. oxLDL amount was notably higher in UAP than in SAP and in UAP the high grade of inflammation was correlated with the increased amount of oxLDL in endothelial cells and macrophages. The exaggerated amount of oxLDL in UAP and the interaction of oxLDL with lectin-like oxLDL (LOX-1) receptor are amplified by the activation of transcriptional factor octamere 1 (OCT-1) with consequent activation of a series of inflammatory endothelial feed-back mechanisms resulting in LOX-1 gene over-expression, endothelial inflammation as well as uncontrolled nuclear factor kappa B (NFkB) activation. Moreover, in UAP genes for signal transducer and activator transcriptional factor 1α (STAT1α), angiotensin converting enzyme (ACE) and numerous pro-inflammatory cytokines were over-expressed. The present results may have clinical relevance because they show that coronary atherosclerosis is a disease not confined to the large arteries but involving the whole coronary tree. In UAP the exaggerated amount of myocardial oxLDL is associated with widespread high grade microvessel inflammation.

Ang II Upregulation of the T-lymphocyte renin-angiotensin system is amplified by low-grade inflammation in human hypertension.

BACKGROUND: Low-grade inflammation facilitates the development of essential hypertension and target organ damage (TOD). Recently, human T-lymphocytes were shown to be endowed with a functional active renin-angiotensin system (RAS). We investigated whether in hypertensive patients a selective angiotensin (Ang) II-driven upregulation of T-cell RAS occurs and whether it is differently modulated in presence of low-grade inflammation. METHODS: T-lymphocytes were obtained from 21 hypertensives (I-II World Health Organization class; 16 males, 5 females; 56 ± 11 years). Low-grade inflammation was defined for high sensitive C-reactive protein (hsCRP) > 2 mg/l. Ten healthy subjects formed the age- and sex-matched control group. After T-lymphocytes isolation, mRNAs for angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor (AT1-R) were quantified by reverse-transcriptase PCR with or without 0.1 pmol/l Ang II in addition to T-cells cultures. Cell pellet and supernatant ACE activity and Ang II content were measured. Cardiac and renal TOD-indexes were evaluated. RESULTS: Both in controls and hypertensives, Ang II-stimulation significantly increased ACE and AT1-R mRNA levels (P < 0.05). In patients, the increase was earlier and higher than controls, with the highest values in hypertensives with > 2 mg/l hsCRP. Peak Ang II-induced ACE and AT1-R mRNA levels were positively related to hsCRP, systolic blood pressure and body mass index (BMI) at the univariate analyses. The stepwise regression analyses selected hsCRP (r = 0.47) and left ventricular mass index (LVMI) (r = 0.50) as the variables independently related to peak ace-gene expression, while BMI resulted independently related to peak AT1-R gene expression (P < 0.001). CONCLUSIONS: In hypertension, an Ang II-driven activation of T-cell RAS, further amplified by low-grade inflammation, does occur and is associated to worse TOD. New therapeutic approaches aimed at this specific target might be proposed to control hypertension and hypertensive damage.

Exaggerated local hand sympathetic but not renin-angiotensin system activation in patients with primary Raynaud's phenomenon.

In Raynaud's disease (RD), an overactivity of sympathetic nervous system (SNS) was hypothesized but only indirect proofs were obtained. Complex interactions between the renin-angiotensin system (RAS) and SNS were reported without clear demonstrations of a RAS involvement. Recently, the use of ACE inhibitors and AT1 receptor antagonists in RD patients showed mixed results. The study of total and regional kinetics of tritiated noradrenaline (NA) and the measurements of local Angiotensin (Ang) I and II arterial-venous gradient were performed in 10 RD patients and 10 controls both in rest conditions and following a cold pressor test (CPT). Hand blood flow (HBF) was measured by strain-gauge plethysmography. Baseline HBF was slightly lower in patients than in controls, but during CPT, it significantly decreased only in RD patients (P < 0.01). Total (3H)-NA clearance and spillover were similar in the two groups throughout the study. On the contrary, baseline hand NA spillover was higher in RD patients than in controls and the difference further increased during CPT. Hand NA spillover was linearly related to HBF (P < 0.001). Arterial-venous Ang I and Ang II gradients were positive without difference between controls and patients throughout the study. In conclusion in RD patients, a pathological waste of NA from sympathetic nervous endings of the hand region, exaggerated by sympathetic stimulation, occurs but an enhanced local Ang II formation was not demonstrable.

Pulmonary injury follows systemic inflammatory reaction in infrarenal aortic surgery.

OBJECTIVE: To investigate whether an inflammatory response occurs in patients undergoing infrarenal aortic abdominal aneurysm repair, the localization and timing (ischemia and/or reperfusion) of this activation, and finally whether it affects postoperative pulmonary function. DESIGN: Prospective, observational study. SETTING: Academic referral center in Italy. PATIENTS: We included 12 patients undergoing infrarenal aortic abdominal aneurysm repair and 12 patients undergoing major abdominal surgery. INTERVENTIONS: Timed measurement of gene activation (angiotensinogen, angiotensin type 1 receptor, angiotensin-converting enzyme, and interleukin-6 genes) in muscle biopsies by reverse transcriptase-polymerase chain reaction (RT-PCR), and prospective assessment of interleukin-6 plasma concentration and pulmonary function (Pao2/FIO2 and Pao2/PAO2 ratios). MEASUREMENTS AND MAIN RESULTS: After 30 mins of aortic clamping, angiotensinogen, angiotensin type 1 receptor, angiotensin-converting enzyme, and interleukin-6 genes were all overexpressed at RT-PCR studies in quadriceps muscle of patients undergoing aortic abdominal aneurysm repair, and the overexpression persisted after reperfusion. In situ hybridization and immunohistochemistry revealed that the inflammatory response was localized in endothelial cells. A significant increase in plasma interleukin-6 concentrations was then detectable at 6 and 12 hrs after reperfusion in aortic abdominal aneurysm surgery compared with patients undergoing abdominal surgery (p < .05). The increase in interleukin-6 plasma concentration was then followed (12 and 24 hrs after surgery) by a significant reduction of Pao2/ FIO2 and Pao2/PAO2 ratios (p < .05 vs. abdominal surgery). CONCLUSIONS: The present study shows that a) during aortic surgery, the genes for interleukin-6 and for the components of the local renin-angiotensin system (angiotensinogen, angiotensin-converting enzyme, and angiotensin type 1 receptor subtype) are activated early in the ischemic muscle, and activation persists during reperfusion; b) interleukin-6 plasma concentration increases only in patients with tissue ischemia (aortic abdominal aneurysm), whereas no changes are detectable in patients with abdominal surgery; and finally c) the occurrence of systemic inflammatory reaction with increased interleukin-6 plasma concentrations is followed by impaired pulmonary function.

Release of preformed Ang II from myocytes mediates angiotensinogen and ET-1 gene overexpression in vivo via AT1 receptor.

UNLABELLED: The role of angiotensin II in pressure overload is still debated because notwithstanding its effects on myocyte contractility angiotensin II is not an obligatory factor for the development of hypertrophy. To define the role of angiotensin II in acute pressure overload we studied the effects of AT1 blockade (valsartan 80mg per day) on myocardial contractility, cardiac growth factor gene expression, and myocardial hypertrophy in aortic banded (60mmHg) pigs. Acute pressure overload caused an abrupt reduction of myocardial contractility, measured by the end-systolic stiffness constant, and a sharp increase in end-systolic stress which rapidly normalized (within 12h) in the placebo group. In AT1-blocked animals end-systolic stiffness constant remained significantly depressed up to 24h and end-systolic stress was still elevated up to 48h (both P<0.05 vs placebo). In both groups confocal microscopy revealed that granular staining of angiotensin II in cardiomyocyte cytoplasm disappeared after 30min of pressure overload. AT1 blockade abolished following cardiac overexpression of angiotensinogen and endothelin-1 genes as shown in RT-PCR studies and the consequent angiotensin II and endothelin-1 release in the coronary circulation. Conversely, insulin-like growth factor-I and ACE mRNA overexpression, as well as the onset of left ventricular mass increase, were not significantly affected by AT1 blockade. IN CONCLUSION: (1) mechanical stress releases preformed angiotensin II from myocyte in vivo; (2) the AT1 blockade abolishes cardiac angiotensin II and endothelin-1 production with delayed recovery of myocardial contractility; whereas (3) the overexpression of insulin-like growth factor-I gene and the development of myocardial hypertrophy are not angiotensin II-mediated effects.