SEQUENTIAL CHANGES IN CIRCULATING LEVELS OF ANGIOTENSIN I AND II, RENIN, AND BRADYKININ AFTER CAPTOPRIL

1979 ◽  
Vol 2 (SP2) ◽  
Author(s):  
John A. Millar ◽  
Colin I. Johnston
Keyword(s):  
Angiotensin I ◽  
Circulating Levels

scholarly journals Sacubitril/valsartan (LCZ696) Significantly Reduces Aldosterone and Increases cGMP Circulating Levels in a Canine Model of RAAS Activation

2018 ◽  
Author(s):  
Jonathan P Mochel ◽  
Chi Hse Teng ◽  
Mathieu Peyrou ◽  
Jerome Giraudel ◽  
Meindert Danhof ◽  
...  
Keyword(s):  
Heart Failure ◽  
Systemic Exposure ◽  
Plasma Renin ◽  
Canine Model ◽  
Angiotensin Receptors ◽  
Angiotensin I ◽  
Once Daily ◽  
Salt Diet ◽  
Low Salt ◽  
Circulating Levels

AbstractSimultaneous blockade of angiotensin receptors and enhancement of natriuretic peptides (NP) by the first-in-class angiotensin receptor neprilysin (NEP) inhibitor sacubitril/valsartan constitutes an effective approach to treating heart failure. This study examined the effects of sacubitril/valsartan (225 and 675mg/day) vs. placebo, sacubitril (360mg/day), valsartan (900mg/day), and benazepril (5mg/day) on the dynamics of the renin-angiotensin-aldosterone system (RAAS) and the NP system in dogs. Beagle dogs (n=18) were fed a low-salt diet (0.05% Na) for 15 days to model RAAS activation observed in clinical heart failure. Drugs were administered once daily during the last 10 days, while the effects on the RAAS and NPs were assessed on days 1, 5, and 10. Steady-state pharmacokinetics of the test agents were evaluated on day 5. Compared with placebo, sacubitril/valsartan (675mg) substantially increased cGMP circulating levels, while benazepril and valsartan showed no effect. Additionally, sacubitril/valsartan (675mg) and valsartan significantly increased plasma renin activity, angiotensin I and angiotensin II concentrations. Finally, sacubitril/valsartan (both doses), and valsartan significantly decreased plasma aldosterone vs. placebo. Systemic exposure to valsartan following sacubitril/valsartan 675mg administration was similar to that observed with valsartan 900mg administration alone. Sacubitril/valsartan favorably modulates the dynamics of the renin and NP cascades through complementary NEP and RAAS inhibition.

Elevated Tissue Factor and Tissue Factor Pathway Inhibitor Circulating Levels in Ischaemic Heart Disease Patients

1998 ◽  
Vol 79 (03) ◽  
pp. 495-499 ◽  
Author(s):  
Anna Maria Gori ◽  
Sandra Fedi ◽  
Ludia Chiarugi ◽  
Ignazio Simonetti ◽  
Roberto Piero Dabizzi ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ischaemic Heart Disease ◽  
Tissue Factor ◽  
Plasma Levels ◽  
Tissue Factor Pathway Inhibitor ◽  
Common Source ◽  
Previous Myocardial Infarction ◽  
Control Subjects ◽  
Tissue Factor Pathway ◽  
Circulating Levels

SummarySeveral studies have shown that thrombosis and inflammation play an important role in the pathogenesis of Ischaemic Heart Disease (IHD). In particular, Tissue Factor (TF) is responsible for the thrombogenicity of the atherosclerotic plaque and plays a key role in triggering thrombin generation. The aim of this study was to evaluate the TF/Tissue Factor Pathway Inhibitor (TFPI) system in patients with IHD.We have studied 55 patients with IHD and not on heparin [18 with unstable angina (UA), 24 with effort angina (EA) and 13 with previous myocardial infarction (MI)] and 48 sex- and age-matched healthy volunteers, by measuring plasma levels of TF, TFPI, Prothrombin Fragment 1-2 (F1+2), and Thrombin Antithrombin Complexes (TAT).TF plasma levels in IHD patients (median 215.4 pg/ml; range 72.6 to 834.3 pg/ml) were significantly (p<0.001) higher than those found in control subjects (median 142.5 pg/ml; range 28.0-255.3 pg/ml).Similarly, TFPI plasma levels in IHD patients were significantly higher (median 129.0 ng/ml; range 30.3-316.8 ng/ml; p <0.001) than those found in control subjects (median 60.4 ng/ml; range 20.8-151.3 ng/ml). UA patients showed higher amounts of TF and TFPI plasma levels (TF median 255.6 pg/ml; range 148.8-834.3 pg/ml; TFPI median 137.7 ng/ml; range 38.3-316.8 ng/ml) than patients with EA (TF median 182.0 pg/ml; range 72.6-380.0 pg/ml; TFPI median 115.2 ng/ml; range 47.0-196.8 ng/ml) and MI (TF median 213.9 pg/ml; range 125.0 to 341.9 pg/ml; TFPI median 130.5 ng/ml; range 94.0-207.8 ng/ml). Similar levels of TF and TFPI were found in patients with mono- or bivasal coronary lesions. A positive correlation was observed between TF and TFPI plasma levels (r = 0.57, p <0.001). Excess thrombin formation in patients with IHD was documented by TAT (median 5.2 μg/l; range 1.7-21.0 μg/l) and F1+2 levels (median 1.4 nmol/l; range 0.6 to 6.2 nmol/l) both significantly higher (p <0.001) than those found in control subjects (TAT median 2.3 μg/l; range 1.4-4.2 μg/l; F1+2 median 0.7 nmol/l; range 0.3-1.3 nmol/l).As in other conditions associated with cell-mediated clotting activation (cancer and DIC), also in IHD high levels of circulating TF are present. Endothelial cells and monocytes are the possible common source of TF and TFPI. The blood clotting activation observed in these patients may be related to elevated TF circulating levels not sufficiently inhibited by the elevated TFPI plasma levels present.

The Pathogenesis of Thrombotic Thrombocytopenic Purpura

1979 ◽  
Author(s):  
H. C. Kwaan
Keyword(s):  
Plasminogen Activator ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Degradation Products ◽  
Vascular Lesions ◽  
Local Defect ◽  
Laboratory Findings ◽  
Thrombocytopenic Purpura ◽  
Fibrin Degradation Products ◽  
Severity Of The Disease ◽  
Circulating Levels

The vascular lesions with microthrombi were studied in 12 patients with thrombotic thrombocytopenic purpura (TTP), diagnosed by the characteristic clinical and laboratory findings and confirmed histologically in each case. While defibrination was not observed, and with only minimal changes in the circulating levels of fibrinogen, fibrin degradation products and plasminogen activator, the microthrombotic lesion was invariably present. Immunofluorescent and histochemical studies indicated that both platelet and fibrin were present in the microthrombi with the platelet components dominant in many cases. Using the fibrin slide method, plasminogen activator was demonstrated in the uninvolved blood vessels but totally absent in the vessels occluded by microthrombi. in contrast, fibrinolysis is always present in the vessels afflicted with other types of thrombosis, such as the microthrombi in disseminated intravascular coagulation. Since circulating fibrinolytic activity was normal in TTP, the absence of vascular fibrinolysis is a local defect due to either inhibition by the platelet deposits or by local vascular damage. The inability of thrombolysis may explain the absence of systemic defibrination and the severity of the disease.

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