Search results for "clam"
showing 10 items of 454 documents
Oxytocin Regulates Neurosteroid Modulation of GABAAReceptors in Supraoptic Nucleus around Parturition
2003
In this study, we investigate how neurosteroid sensitivity of GABAAreceptors (GABAARs) is regulated. We examined this issue in neurons of the supraoptic nucleus (SON) of the rat and found that, during parturition, the GABAARs become insensitive to the neurosteroid allopregnanolone attributable to a shift in the balance between the activities of endogenous Ser/Thr phosphatase and PKC. In particular, a constitutive endogenous tone of oxytocin within the SON after parturition suppressed neurosteroid sensitivity of GABAARs via activation of PKC. Vice versa before parturition, during late pregnancy, application of exogenous oxytocin brings the GABAARs from a neurosteroid-sensitive mode toward a …
Inhibition by Fendiline of the Transient Outward Current in Rat Ventricular Cardiomyocytes
1999
The effects of fendiline on the transient outward current (Ito) were investigated in rat ventricular cardiomyocytes. Extracellularly applied fendiline reduced peak and steady-state current amplitude of Ito; the inactivation of Ito was accelerated by the drug, which reflects onset of block. The described effects were concentration dependent: half-maximal effects were achieved at approximately 3 microM fendiline. Intracellularly applied fendiline (3 microM) did not affect Ito within 5 min. The steady-state current amplitude of Ito was more efficiently suppressed by the drug at 22 +/- 1 degrees C than at 36 +/- 1 degrees C. The recovery of Ito was analyzed by the application of twin depolarizi…
Mechanism of Block by 4-Aminopyridine of the Transient Outward Current in Rat Ventricular Cardiomyocytes
1998
The effects of 4-aminopyridine (4-AP) on the transient outward current (I to ) were investigated in rat ventricular cardiomyocytes at different values of intracellular pH (pH i ) and extracellular pH (pH o ). The 4-AP was administered either extracellularly (bath application) or intracellularly (diffusion from the intrapipette solution). The 4-AP diminished I to given either from inside or outside the cell membrane. The block by extracellularly applied 4-AP (4-AP o ) of the peak amplitude of I to was decreased by external acidification but increased by external alkalinization: conversely. the block by 4-AP o was decreased by internal alkalinization but increased by internal acidification. I…
Voltage-Dependent Effects of Barnidipine in Rat Vascular Smooth Muscle
2003
The effects of the dihydropyridine nifedipine and its more lipophilic congener, barnidipine, were investigated in smooth muscle preparations from the rat in resting and depolarizing conditions. Both drugs relaxed precontracted aortic rings more potently in depolarizing conditions, barnidipine being more potent than nifedipine. Currents through Ca 2+ channels in rat vascular smooth muscle cells (A7r5) and in isolated rat cardiomyocytes were reduced more potently by both drugs at a holding potential of-40 mV than at -80 mV. However, barnidipine and nifedipine were more effective in reducing the current in A7r5 cells than in cardiomyocytes. The IC 50 obtained in aortic rings and in A7r5 cells …
Depolarization-induced influx of sodium in response to phenylephrine in rat atrial heart muscle.
1991
1. The effects of alpha 1-adrenoceptor stimulation on transmembrane potential, currents and ion fluxes were investigated in multicellular preparations and/or single cells obtained from the left atrium of rat hearts. 2. In multicellular preparations, phenylephrine caused a concentration-dependent positive inotropic effect, an increase in action potential duration, and a decrease in resting potential; the effects were antagonized by phentolamine. 3. In the presence of phenylephrine (100 mumol/1), two levels of resting potential were observed when the preparations were, alternately, electrically stimulated or kept at rest (-74 +/- 1 mV during activity and -62 +/- 4 mV at rest; mean +/- S.E.M.;…
Diabetes impairs the atrial natriuretic peptide relaxant action mediated by potassium channels and prostacyclin in the rabbit renal artery.
2012
Diabetes is associated with increased prevalence of hypertension, cardiovascular and renal disease. Atrial natriuretic peptide (ANP) plays an important role in cardiovascular pathophysiology and is claimed to have cardioprotective and renoprotective effect in diabetic patients. The working hypothesis was that alloxan-induced diabetes might modify the vascular effects of ANP in isolated rabbit renal arteries and the mechanisms involved in such actions. Plasma ANP levels were higher in diabetic rabbits than in control rabbits. ANP (10(-12)-10(-7)M) induced a relaxation of precontracted renal arteries, which was lower in diabetic than in control rabbits. In arteries from both groups of animals…
A minimally invasive approach for aortobifemoral bypass procedure
2011
Surgical aortobifemoral bypass procedure for aortoiliac occlusive disease remains the gold standard treatment despite rapidly expanding range of indications for endovascular repair. Besides several disadvantages such as dysparaesthesias, hernias, and unpleasant outcome, transperitoneal exposure of the aorta is also associated with operative autonomic nerve injury. In five male patients, infrarenal aorta was exposed through a small (8 cm) supraumbilical midline incision. Incision of the posterior peritoneum above the infrarenal aorta was limited to 3 cm. A 1 cm infraumbilical incision allowed transperitoneal placement of the distal aortic clamp outside of the operative field. Four centimeter…
Glycemic Durability of Rosiglitazone, Metformin, or Glyburide Monotherapy
2006
BACKGROUND: The efficacy of thiazolidinediones, as compared with other oral glucose-lowering medications, in maintaining long-term glycemic control in type 2 diabetes is not known. METHODS: We evaluated rosiglitazone, metformin, and glyburide as initial treatment for recently diagnosed type 2 diabetes in a double-blind, randomized, controlled clinical trial involving 4360 patients. The patients were treated for a median of 4.0 years. The primary outcome was the time to monotherapy failure, which was defined as a confirmed level of fasting plasma glucose of more than 180 mg per deciliter (10.0 mmol per liter), for rosiglitazone, as compared with metformin or glyburide. Prespecified secondary…
Distinct Roles of Classical and Lectin Pathways of Complement in Preeclamptic Placentae
2022
Pre-eclampsia is a pregnancy complication characterized by defective vascular remodeling in maternal decidua responsible for reduced blood flow leading to functional and structural alterations in the placenta. We have investigated the contribution of the complement system to decidual vascular changes and showed that trophoblasts surrounding unremodeled vessels prevalent in preeclamptic decidua fail to express C1q that are clearly detected in cells around remodeled vessels predominant in control placenta. The critical role of C1q is supported by the finding that decidual trophoblasts of femaleC1qa-/-pregnant mice mated toC1qa+/+male mice surrounding remodeled vessels express C1q of paternal …
Perceived determinants of physical activity among women with prior severe preeclampsia: a qualitative assessment.
2022
Abstract Background The objective of this study was to (1) qualitatively identify the perceived determinants of physical activity among women who have experienced severe preeclampsia, and (2) examine whether these determinants are consistent with the overarching processes outlined in the integrated behavior change (IBC) model, a novel model that describes physical activity as being a result of motivational, volitional, and automatic processes. Methods Patients (n = 35) of the Follow-Up PreEClampsia (FUPEC) Outpatient Clinic, Erasmus MC, the Netherlands, participated in an anonymous online survey. The main outcomes under study were their perceived determinants of physical activity. Responses…