Role of the ∝-adrenoceptor subtypes in constriction of the systemic capacitance vessels, a study with the measurement of mean circulatory pressure (MCP)
0
Citation
0
Reference
10
Related Paper
Keywords:
Constriction
The volume-pressure relationship of the vasculature of the body as a whole, its vascular capacitance, requires a measurement of the mean circulatory filling pressure (Pmcf). A change in vascular capacitance induced by reflexes, hormones, or drugs has physiological consequences similar to a rapid change in blood volume and thus strongly influences cardiac output. The Pmcf is defined as the mean vascular pressure that exists after a stop in cardiac output and redistribution of blood, so that all pressures are the same throughout the system. The Pmcf is thus related to the fullness of the circulatory system. A change in Pmcf provides a uniquely useful index of a change in overall venous smooth muscle tone if the blood volume is not concomitantly changed. The Pmcf also provides an estimate of the distending pressure in the small veins and venules, which contain most of the blood in the body and comprise most of the vascular compliance. Thus the Pmcf, which is normally independent of the magnitude of the cardiac output, provides an estimate of the upstream pressure that determines the rate of flow returning to the heart.
Venous return curve
Cite
Citations (224)
Cite
Citations (249)
Hypervolemia
Mean arterial pressure
Cite
Citations (17)
Intravascular volume status
Venous return curve
Systemic circulation
Cite
Citations (2)
The mean circulatory filling pressure technique has been used to assess total body venous tone. It involves measuring central venous pressure (CVP) at 5-8 s following circulatory arrest. This study examines if CVP and portal venous pressure (PVP) equilibrate when circulation is stopped by inflating a balloon implanted in the right atrium. CVP and PVP were measured in the control condition and after intravenous bolus injections of norepinephrine (NE, 1.6 microgram/kg), angiotensin II (ANG II, 1.3 microgram/kg), and isoproterenol (Iso, 0.5 microgram/kg) in conscious and pentobarbital-anesthetized rats. In conscious rats, CVP was similar to PVP after circulatory arrest under conditions of normal, elevated, or reduced vascular tone. In anesthetized rats, CVP was similar to PVP in the control condition and after intravenous bolus injection of NE and Iso but was less than PVP after the administration of ANG II. Therefore, mean circulatory filling pressure may not fully reflect total body venous tone in anesthetized, surgically stressed rats.
Bolus (digestion)
Intravenous bolus
Microgram
Venous return curve
Cite
Citations (18)
Starling
Venous return curve
Homeostasis
Cite
Citations (0)
Cite
Citations (0)
Venous return curve
Bolus (digestion)
Cardiac index
Mean blood pressure
Cite
Citations (9)
Venous return curve
Contractility
Cite
Citations (1)
AIM: To study the dynamic mechanism of villosity injury.METHODS: A small intestinal villosity microvessels model and a circulatory simulation system were made. The flow volume and pressure in microvessels model were measured under different systemic circulatory state. RESULTS: The flow volume in model was closely related to systemic circulatory pressure. As the systemic circulatory pressure reduced, the volume and pressure of top capillaries in network decreased much more than that of the middle and bottom capillasies. As the systemic circulatory pressure increased, the volume and pressure of top capillaries in network increased much less than that of the middle and bottom capillasies. CONCLUSION: The top capillaries in network were much more sensitive than middle and bottom capillarise when the systemic circulatory pressure was fell. The microvessels structure of villosity is a special, easy ischemia-injuring structure.
Circulatory collapse
Cite
Citations (0)