Showing papers by "Barbara Casadei published in 2002"

Cardiac Nitric Oxide Synthase 1 Regulates Basal and β-Adrenergic Contractility in Murine Ventricular Myocytes

Abstract: Background— Evidence indicates that myocardial NO production can modulate contractility, but the source of NO remains uncertain. Here, we investigated the role of a type 1 NO synthase isoform (NOS1), which has been recently localized to the cardiac sarcoplasmic reticulum, in the regulation of basal and β-adrenergic myocardial contraction. Methods and Results— Contraction was assessed in left ventricular myocytes isolated from mice with NOS1 gene disruption (NOS1−/− mice) and their littermate controls (NOS1+/+ mice) at 3 stimulation frequencies (1, 3, and 6 Hz) in basal conditions and during β-adrenergic stimulation with isoproterenol (2 nmol/L). In addition, we examined the effects of acute specific inhibition of NOS1 with vinyl-l-N-5-(1-imino-3-butenyl)-l-ornithine (L-VNIO, 500 μmol/L). NOS1−/− myocytes exhibited greater contraction at all frequencies (percent cell shortening at 6 Hz, 10.7±0.92% in NOS1−/− myocytes versus 7.21±0.8% in NOS1+/+ myocytes; P<0.05) with a flat frequency-contraction relationsh...

Mechanisms Controlling Blood Flow and Arterial Pressure

Abstract: The key word to consider when thinking about the control of blood flow and arterial blood pressure (ABP) is ‘integration’. The body has developed a large number of integrated homeostatic mechanisms in order to keep ABP and flow at around constant levels, with the aim of maintaining adequate perfusion of the vital organs both at rest and in situations where there is a change in environment or workload. Maintenance of normal ABP is mainly dependent on the balance between cardiac output and peripheral vascular resistance (PVR), related by the equation: Mean ABP = Cardiac output × PVR