Rats with chronic heart failure (CHF) develop increased myogenic constriction in mesenteric resistance arteries. Here we investigated increased myogenic constriction in relation to alterations in EDHF- and NO-mediated dilatation in CHF-rats. Male Spraque-Dawley rats were subjected to myocardial-infarction or sham-surgery. At 9-10 weeks after surgery, isolated mesenteric artery ring preparations...

After transecting the squid giant axon in the presence of an artificial external medium, which was composed of the ions normally present in squid blood, the cut ends of the axon constrict. This constriction could be completely blocked by cutting the axon in the presence of an artificial internal medium composed of the ions normally present inside the axon. By interchanging the ions in the inter...

Recent reports suggest that tidal stretches do not cause significant and sustainable dilation of constricted intact airways ex vivo. To better understand the underlying mechanisms, we aimed to map the physiological stretch-induced molecular changes related to cytoskeletal (CSK) structure and contractile force generation through integrin receptors. Using ultrasound, we measured airway constricti...

Despite considerable evidence suggesting that hypertension contributes to the development and progression of atherosclerosis, the causative links remain unclear. We have tested the effects of chronic hypertension induced by suprarenal aortic constriction on the development of atherosclerosis in apolipoprotein E-deficient (Apoe-/-) mice. Compared with a sham operation, narrowing the aortic lumin...

Murine collagen-induced arthritis (mCIA) is characterized by decreased vascular constriction responses and increased MMP-9. Here, we describe additional histological alterations within the aorta and surrounding perivascular adipose tissue (PVAT), study the role of PVAT in constriction response, and investigate the potential involvement of death receptor 3 (DR3). mCIA was induced in wild-type (W...

Indomethacin produces constriction and hypoxia of the fetal ductus arteriosus. This is associated with death of smooth muscle cells in the ductus wall and an increased incidence of patent ductus arteriosus in the newborn period. We used fetal sheep to determine which factors are responsible for indomethacin-induced hypoxic cell death. Cell death in the ductus wall is directly related to the deg...

AIM To determine the accuracy of locating the apical constriction using apex locators. METHODOLOGY Extracted teeth were micro-CT scanned preoperatively to localize the apical constriction. Electronic length measurements of 91 root canals were made using nine electronic apex locators (EAL) connected to a mounting model. Distances from the major foramen were recorded at each scale bar of the EA...

To assess if the renal damage observed in rats with diabetes and hypertension is due to hemodynamic or metabolic changes, a progressive aortic constriction between the two renal arteries has been done in streptozotocin-induced diabetic rats (constriction + diabetes group) and in nondiabetic rats (constriction group). This model allows us to study two kidneys subjected to different perfusion pre...

Intravital microscopy of the rat cremaster muscle was used to evaluate changes in vessel constriction, vessel permeability, and leukocyte adhesion during and after photodynamic therapy (PDT). Animals were given Photofrin doses of 0-25 mg/kg i.v. 24 h before treatment. Cremaster muscles were exposed to 135 J/cm2 light at 630 nm. Animals given 5 mg/kg Photofrin showed no vessel constriction or in...

Constriction of the fetal ductus arteriosus (DA) has disparate effects on mean and phasic hemodynamics, as mean DA blood flow is preserved until constriction is severe, but DA systolic and diastolic blood velocities change with only mild constriction. To determine the basis of this disparity and its physiological significance, seven anesthetized late-gestation fetal sheep were instrumented with...