Active and passive release of blood from canine spleen and small intestine

Donald, DE; Aarhus, Lawrence L.

doi:10.1152/ajplegacy.1974.227.5.1166

Cited by 43 publications

(25 citation statements)

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“…Carneiro & Donald (1977) reported that carotid occlusion or haemorrhage resulted in much larger changes in splenic volume than in the volumes of both the liver and intestine together. Other studies have reported that sympathetic stimulation in dogs and cats decreases splenic volume by between 25 and 70% (Greenway, Lawson & Stark, 1968;Opdyke & Ward, 1973;Donald & Aarhus, 1974).…”

Section: Methodsmentioning

confidence: 93%

Mechanisms responsible for changes in abdominal vascular volume during sympathetic nerve stimulation in anaesthetized dogs

Noble

Drinkhill²,

Myers³

et al. 1997

Experimental Physiology

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SUMMARYThis study was designed to determine the extent to which the decrease in volume of blood in the abdominal circulation in response to sympathetic stimulation was due to a passive effect of decreasing flow rather than an active constriction of the capacitance vessels. In dogs anaesthetized with a-chloralose (100 mg kg-' I.v.) the abdominal circulation was vascularly isolated and perfused either at constant flow or at constant pressure, and drained at constant pressure from the inferior vena cava. Changes in volume were determined by integration of the differences between inflow and outflow. Supramaximal stimulation of both splanchnic (sympathetic) nerves at 1 Hz decreased abdominal volume during constant pressure perfusion (active and passive components) by 3 04 + 0-58 ml kg-1 and at constant flow (active responses only) by 2 30 + 0.49 ml kg-1 (means + S.E.M.). The responses at 8 Hz were respectively 9.52 + 0 91 and 5 09 + 0 49 ml kg-'.The proportion of the responses calculated to be passive at 1 and 8 Hz was 23 + 6 3 and 45 + 5.1 %, respectively. These responses were almost identical to those induced by changing inflow by increasing the pump speed. Following ligation of the splenic pedicle, the responses during both constant pressure and constant flow were reduced by similar amounts, indicating that only the active response was affected. After ligation of the splenic pedicle, the proportion of the response calculated to be passive at I and 8 Hz increased to 44 + 8 0 and 62 + 3.7 %, respectively. These results indicate the importance of passive volume changes in affecting abdominal volume, particularly following ligation of the splenic circulation.

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Section: Methodsmentioning

confidence: 93%

Mechanisms responsible for changes in abdominal vascular volume during sympathetic nerve stimulation in anaesthetized dogs

Noble

Drinkhill²,

Myers³

et al. 1997

Experimental Physiology

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“…As far as we are aware, there have been no previous studies of active responses in that region. Earlier investigations determined changes in weight (Selkurt & Johnson, 1958;Donald & Aarhus, 1974) or volume (Folkow et al 1963) in intestinal loops with the perfusion uncontrolled. Others have determined effects on venous perfusion pressures (Iizuka et al 1970) which, although indicative of active responses, are impossible to quantify.…”

Section: Discussionmentioning

confidence: 99%

“…However, the splanchnic circulation (the gastrointestinal circulation and associated viscera which drain through the portal vein) is also likely to make a contribution. There have been reports that either direct or reflex stimulation of sympathetic nerves reduces intestinal weight or volume (Donald & Aarhus, 1974;Rothe et al 1978), but these reports did not distinguish between the active response and volume changes secondary to changes in blood flow, so the role of the splanchnic circulation in capacitance control remains unclear. The aim of the present study, therefore, was to evaluate the contribution of the splanchnic vascular bed to the volume changes in the abdominal circulation and to assess both the active capacitance responses and the volume changes occurring secondary to the reflex changes in flow.…”

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confidence: 99%

Reflex control of splanchnic blood volume in anaesthetized dogs

Noble

Drinkhill

Myers

et al. 1998

The Journal of Physiology

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In chloralose‐anaesthetized, artificially ventilated dogs, the splenic pedicle was tied and the carotid sinuses were vascularly isolated and perfused at controlled pressures. In Series 1 experiments, the hepatosplanchnic circulation was perfused through the abdominal aorta with a tie on the aorta separating it from the caudal circulation, which was perfused through the femoral arteries. The two circulations were drained from cannulae in the inferior vena cava and the femoral veins, with a tie on the inferior vena cava separating the two. In Series 2, the splanchnic circulation drained from the portal vein. In both series, inflows and outflows were measured and integrated to derive volume changes. Capacitance responses were assessed during constant flow, and capacitance plus passive responses were obtained during constant pressure perfusion. In Series 1, an increase in carotid sinus pressure (from 8 to 26 kPa) during constant flow and constant pressure perfusion increased hepatosplanchnic volume by 2.5 and 5.7 ml (kg body weight)−1, respectively. The volume of the subdiaphragmatic circulation did not increase during constant flow, but during constant pressure it increased by 2.0 ml (kg body weight)−1. In Series 2, increasing carotid pressure during constant flow and constant pressure increased the volume of the splanchnic circulation by 0.5 and 4.2 ml (kg body weight)−1, respectively. These results confirm that carotid baroreceptor stimulation causes larger volume changes during constant pressure perfusion than during constant flow perfusion. Also, the active capacitance change in the splanchnic circulation is small in relation to the passive response. We propose that in dogs (following splenic ligation), the major active capacitance control is from the liver. However, large passive changes in splanchnic volume occur due to changes in flow.

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“…Furthermore, not only does the abdominal circulation make the major contribution to capacitance control (Karim & Hainsworth, 1976;Noble et al 1997) but its high compliance, at about 9.25 ml kg-' kPa-', accounts for about half the entire vascular compliance of the whole body (Echt, Lange & Gauer, 1974;Drees & Rothe, 1974;Larochelle & Ogilvie, 1976). In the dog, a large contribution to the active response is from the spleen (Greenway, Lawson & Stark, 1968;Donald & Aarhus, 1974;Noble et al 1997). Since humans do not possess a large contractile spleen, any extrapolation of results from dogs to humans should take account of the fact that the canine spleen contributes 40 % or more of the active volume change.…”

Section: Discussionmentioning

confidence: 99%

Blood mobilization from the liver of the anaesthetized dog

Noble¹,

Drinkhill²,

Myers³

et al. 1998

Experimental Physiology

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SUMMARYThe abdominal circulation contains a high proportion of the total blood volume and this can change either passively in response to changes in vascular distending pressure or actively (termed a capacitance response) to changes in sympathetic nervous activity. The liver is the largest abdominal organ and this study was designed to evaluate its potential contribution to overall vascular capacitance and compliance. In chloralose anaesthetized dogs, the liver was vascularly isolated, perfused through the portal vein and hepatic artery at either constant pressures or constant flows and drained from the hepatic veins at constant pressure. Changes in vascular resistance were assessed from changes in inflow pressures or flows and hepatic blood volume was determined by differences between net inflow and outflow. During constant flow perfusion the change in hepatic volume (capacitance change) in response to supramaximal stimulation of sympathetic nerves at 16 Hz was (mean + S.E.M.) -2-40 + 0-61 ml (kg body weight)-'. This response was not significantly different during constant pressure perfusion. The changes in portal venous and hepatic arterial pressures during stimulation at constant flow perfusion were +0-67 + 0.13 and +4-92 + 0-67 kPa, respectively. The compliance of the liver, assessed as the change in volume to a change in hepatic venous pressure, was +544 + 0-18 ml kg-' kPa-. These results indicate that the liver has a major capacitance role, comparable to that of the canine spleen and, in addition, is highly compliant. No evidence was found to suggest that a sphincter on the hepatic outflow exists. Assuming similar responses occur in humans, who do not possess a large contractile spleen, the liver would be the most important controllable blood reservoir in the body.

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Active and passive release of blood from canine spleen and small intestine

Cited by 43 publications

References 0 publications

Mechanisms responsible for changes in abdominal vascular volume during sympathetic nerve stimulation in anaesthetized dogs

Mechanisms responsible for changes in abdominal vascular volume during sympathetic nerve stimulation in anaesthetized dogs

Reflex control of splanchnic blood volume in anaesthetized dogs

Blood mobilization from the liver of the anaesthetized dog

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