(Pdf) salt water promotes hypertension in dahl-s rats. electricity deregulation


The impact of hypertension on left ventricular (LV) structure, pump function, and heart failure in Dahl salt-sensitive rats is poorly characterized but hypothesized to yield insights into the pathophysiology of heart failure with normal or preserved ejection fraction. Eighty Dahl salt-sensitive rats were fed either a high-salt (HS) or low-salt (LS, controls) diet starting at age 7 weeks. Ventricular properties were measured by echocardiography, hemodynamics and end-systolic and end-diastolic pressure-volume relationships (ESPVR and EDPVR, respectively). Compared with LS controls, HS rats developed severe hypertension and LV hypertrophy. At week 12, HS rats developed passive diastolic dysfunction (leftward/upward shifted EDPVR, increased chamber stiffness gas or electricity more expensive) with reductions in end-diastolic volume. However, the ESPVR also shifted upward (enhanced end-systolic function) so that overall pump function was enhanced compared with LS, and there was no change in end-diastolic pressure (EDP). At 16 and 20 weeks, HS hearts enlarged so that end-diastolic volumes and EDPVRs became similar to the respective age-matched LS controls. Concomitantly, the ESPVRs and overall pump function curves also moved toward controls, and ejection fraction declined. Despite normal or enhanced overall pump function at these times, EDP and wet lung weight increased, indicative of development of heart failure. In the Dahl salt-sensitive rat, which pathophysiologically retains salt and water, the development of heart failure (increased EDP and wet lung weight) is dissociated from changes in passive diastolic and active systolic properties. These observations suggest that a volume overload sate plays an important pathophysiological role in development of heart failure despite preserved overall ventricular pump function in this model of chronic hypertension.

Treatment with OLM plus AZE attenuated changes in the expression of collagen isoforms and a decrease in the ratio of elastin to collagen in the left ventricle and prevented the increase in myocardial stiffness and diastolic dysfunction in DS rats in a manner independent of the hypotensive effect of these drugs. Such treatment also inhibited the expression and activation of elastolytic proteases (including cathepsins S and K and metalloproteinases-2, -9, and -12), NADPH oxidase-dependent superoxide production, and inflammatory changes in the failing myocardium. All these effects were mimicked by treatment with apocynin.

The changes in collagen isoform expression and the decrease in the elastin to collagen ratio in the failing myocardium likely account for the increase in diastolic stiffness in this model of hypertensive heart failure. Administration of angiotensin receptor and calcium channel blockers prevented these changes in a manner independent of the hypotensive effect of these drugs by inhibiting the increase in elastolytic activity induced by activation of NADPH oxidase.

The syndrome of heart failure in the setting of normal ejection fraction electricity usage by appliance (HFNEF) is manifest in a clinically heterogeneous group of patients with multiple and varied comorbid conditions. In this report, we review available data derived from pressure-volume (PV) analyses in patients with and in animal models of HFNEF. Pressure-volume analysis of ventricular function is challenging in the clinical setting but provides unique insights into the systolic, diastolic, and overall pumping grade 9 electricity unit review characteristics of the heart. Results of such analyses have thus far been limited to small cohorts of patients but suggest that different cohorts of patients with HFNEF having PV relations that imply different pathophysiologic mechanisms exist. This emphasizes the need to take a view of this syndrome, which extends beyond diastolic dysfunction, particularly when it comes to proposing and investigating therapeutic targets. We therefore propose that progress can be made in advancing therapeutics for HFNEF if it is appreciated that different underlying pathophysiologic mechanisms may be important in different cohorts and if attention expands beyond diastolic dysfunction as the sole target. Similar to the success that was achieved in advancing therapeutics for systolic heart failure when attention shifted away from the heart to the neurohormonal and renal axes, our interpretation of data in human beings and in animal models suggests that addressing similar targets (perhaps not in exactly the same manner) may prove to be fruitful, at least for some patients with HFNEF as well.

Systemic and glomerular hypertension, hyperlipidemia, and massive proteinuria have been described as risk factors for the development of focal glomerulosclerosis (FGS). Previous studies have shown that Dahl salt-sensitive (S) rats with severe hypertension have elevated glomerular pressures and develop extensive FGS. In the present study, we determined whether Dahl S rats exhibit other risk factors for FGS. Dahl S rats were found to have elevated serum triglycerides at six weeks of age, compared to Dahl salt-resistant (R) rats. Between six and 24 weeks, systemic hypertension and progressive increases in both serum lipids and albuminuria occurred in Dahl S rats fed high salt (4% NaCl) chow. No changes gas pump heaven in blood pressure or serum lipids occurred in Dahl R rats fed high salt. At 30 weeks, the incidence of FGS was 20 times greater in hypertensive Dahl S than in Dahl R. In a separate study, we compared risk factors for FGS in Dahl S rats and spontaneously hypertensive rats (SHR). The magnitude of glomerular capillary pressure, serum lipid levels, and urine albumin excretion were measured in male Dahl S rats and male SHR between 12 and 20 weeks of age. Normal values for the various parameters were established in a group of normotensive male Sprague-Dawley rats. For this study, all rats were fed standard chow containing 0.6% NaCl. Blood pressure was elevated (P less than .01) in Dahl S (142 +/- 2 mm Hg) and in SHR (173 +/- 3 mm Hg) compared to the Sprague-Dawley rats (117 +/- 3 mm Hg). Glomerular capillary pressure, however, was similar in all three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

S and R female rats were raised on a 1% NaCl diet, and excretion rates of urinary protein, kallikrein esterase activity, and PGE2 were measured (1) at 1 1/2 months of age, when both S and R rats were normotensive, (2) at 3 months of age, when S rats were mildly hypertensive and R controls remained normotensive, and (3) at 6 months of age, when S rats were markedly hypertensive relative to the still normotensive R rats. Urinary protein excretion rate in S compared to R rats was slightly elevated at 1 1/2 months of age and greatly elevated at 3 and 6 months of age. Urinary kallikrein was measured by hydrolysis of TAME after separation of kallikrein from nonkallikrein TAME esterases on DEAE-Sephadex minicolumns. Kallikrein TAME esterase activity was the same in 1 1/2-month-old S and R rats but became reduced in S relative to R rats at 3 and 6 months of age, concomitant with the development of hypertension and marked proteinuria. Urinary PGE2 was decreased in S rats as compared to R rats at all ages, and therefore the strain difference in urinary PGE2 preceded the development of strain differences in blood pressure and urinary kallikrein activity. We conclude that gas near me app (1) reduced excretion of urinary kallikrein TAME esterase activity in S rats is probably secondary to hypertension and severe proteinuria and (2) decreased urinary PGE2 excretion in prehypertensive S rats is compatible with, but does not prove, the presence of a primary defect in intrarenal PGE2 production that could be involved in initiating hypertension.

To examine both of the target vessels and the optimal time of their endothelial denudation to study vascular restenosis after balloon injury in cholesterol-loaded rabbits, we made 36 atherosclerotic rabbits by feeding a hypercholesterol diet, and histologically examined the onset time and the development of atherosclerosis. Atheromatous changes were observed first after the 5th week in the … [Show full abstract] thoracic aorta from the start of the diet, and then extended to the abdominal aorta, coronary artery with time. The atherosclerotic lesions in the thoracic aorta and the proximal portion of the coronary artery showed high-grade concentric intimal thickening with luminal stenosis. The abdominal aortic lesion mildly progressed. In the renal, carotid and femoral arteries, in contrast, slight atheroscleromatous changes developed during the diet period. These results suggest that the thoracic and abdominal aortas and the coronary artery would be suitable as target vessels to study vascular restenosis after balloon injury, and the endothelial denudation of these vessels gas symptoms should be performed between the 8th and 15th week in this diet protocol for an accurate analysis. Read more