Influence of naloxone on the total capacitance vasculature of the dog.

Bell, Leonard; Maratea, Edward; Rutlen, D. L.

doi:10.1172/jci111903

Cited by 7 publications

(3 citation statements)

References 21 publications

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“…Support for this speculation is found in the work of Bell who reported that an infusion of NAL increased extra-splanchnic blood volume resulting in a mobilization of the peripheral blood volume. The net effect of these changes may be to reduce the amount of blood flow to working muscle and increasing the perfusion of skin during exercise in the heat (Bell et al 1985). …”

Section: Discussionmentioning

confidence: 99%

Hormonal responses to opioid receptor blockade: during rest and exercise in cold and hot environments

Armstrong

Hatfield

2006

Eur J Appl Physiol

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Opioid receptors appear to modulate a variety of physiological and metabolic homeostatic responses to stressors such as exercise and thermally extreme environments. To more accurately determine the role of the naloxone (NAL) sensitive opioid receptor system during rest and exercise, subjects were subjected to concomitant environmental thermal stress. Fifteen untrained men rested or performed low intensity (60% VO2peak) or high intensity (80% VO2peak) exercise on a cycle ergometer for 60 min in an environmental chamber during cold (0 degrees C) hot (35 degrees C) air exposure while receiving an infusion of normal saline (SAL) or NAL (0.1 mg kg(-1)). Plasma adrenocorticotropin hormone (ACTH), immunoreactive beta-endorphin (IBE), cortisol and growth hormone were measured at baseline and every 15 min while in the chamber. Time to exhaustion was significantly reduced during high intensity exercise in the heat (P<0.0001). NAL significantly (P=0.0004) reduced the time to exhaustion (38.3+/-2.1 min) during high intensity exercise in the heat compared to SAL (49.4+/-2.1 min). ACTH and IBE increased during hot conditions and cold attenuated this response. Plasma concentrations of IBE, ACTH, and growth hormone increased significantly with NAL during high intensity exercise in the heat compared to SAL. Cold attenuated the response of ACTH, IBE and cortisol to NAL. NAL administration exaggerates plasma hormone concentration during high intensity exercise in the heat, but not cold. These results support a regulatory effect of the opioid receptor system on physiological responses during exercise in thermally stressful environments. Future research should be directed to more clearly defining the effect of environmental temperature on the mechanism of hypothalamic-pituitary-adrenal hormonal release during exercise and hot environmental temperatures.

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Section: Discussionmentioning

confidence: 99%

Hormonal responses to opioid receptor blockade: during rest and exercise in cold and hot environments

Armstrong

Hatfield

2006

Eur J Appl Physiol

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“…Since blood was returned to the right atrium at a constant rate, it was possible to record changes in total intravascular capacity as the inverse of changes in reservoir volume, which were recorded every minute to the nearest 2 ml. This technique is similar to that described previously (Bell et al 1985) except that the superior vena cava was drained via a catheter which was advanced from an incision in the inferior vena cava through the right atrium and which was securely ligated in the superior vena cava.…”

Section: A T E R I a L S And M E T H O D Smentioning

confidence: 99%

“…In the first five animals, a second infusion of angiotensin was carried out. In two of these five animals, and in the other three animals, abdominal evisceration was performed as previously described (Bell et al 1985) and angiotensin was infused once more. In four of these eviscerated animals, all four limbs were securely ligated, whereafter angiotensin was again infused.…”

Section: A T E R I a L S And M E T H O D Smentioning

confidence: 99%

Influence of angiotensin on total intravascular capacity in the anaesthetized pig

Rutlen

Helgesen

Christensen

et al. 1990

Acta Physiologica Scandinavica

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The present study examined the influence of angiotensin on total intravascular capacity. In eight anaesthetized pigs, splenectomy, carotid sinus denervation and cervical vagotomy were performed. Blood was drained from the venae cavae to an extracorporeal reservoir and returned to the right atrium at a constant rate so that changes in total intravascular volume could be recorded as the inverse of changes in reservoir volume. Angiotensin administration at 0.2 microgram kg-1 min-1 i.v. for 5 min was associated with a decrease in total intravascular volume of 57 +/- 6 ml (P less than 0.05) and an increase in aortic pressure from 96 +/- 5 to 119 +/- 6 mmHg (P less than 0.05). With subsequent angiotensin administration in five of the animals, the responses were not attenuated. In five of the animals, angiotensin was associated with a decrease in intravascular volume of 72 +/- 8 ml (P less than 0.05) before abdominal evisceration and 33 +/- 13 ml (P less than 0.05) after evisceration. These responses were significantly different from each other. In four of these eviscerated animals, angiotensin was associated with a decrease in intravascular volume of 35 +/- 17 ml (P less than 0.05) before ligation of all four limbs and a decrease of 36 +/- 4 ml (P less than 0.05) after limb ligation. Thus, angiotensin acts directly to decrease total intravascular volume. The decrease is due to decreases in both splanchnic and extrasplanchnic volume. The extrasplanchnic volume decrement is not due to decreases in skeletal muscle or cutaneous tissue intravascular capacity in the limbs.

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The role of the splanchnic circulation in the regulation of total intravascular volume during alpha adrenergic receptor stimulation

Bell

Rutlen

1986

Pflugers Arch.

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Previous studies have not defined the contribution of the splanchnic circulation to the total intravascular volume change associated with selective alpha adrenergic receptor stimulation. Since the splanchnic circulation is responsible for the total volume changes associated with other types of selective autonomic receptor stimulation, the present study was undertaken to examine the influence of alpha adrenergic receptor stimulation on splanchnic intravascular volume, the hemodynamic mechanism responsible for the splanchnic volume change, and the contribution of the splanchnic volume change to the change in total volume. In 35 anesthetized dogs, blood from the vena cavae was drained into an extracorporeal reservoir and returned to the right atrium at a constant rate so that changes in total intravascular volume could be measured as reciprocal changes in reservoir volume. Phenylephrine infusion (100 micrograms/min) for 20 min in 28 dogs was associated with a decrease in total volume of 64 +/- 17 (SEM) ml (P less than 0.0001). The response was abolished by either alpha adrenergic blockade or evisceration but was not attenuated by beta adrenergic blockade, sinoaortic baroreceptor denervation, ganglionic blockade, or splenectomy. In 5 animals with separate splanchnic perfusion and drainage, total and splanchnic volumes decreased 59 +/- 8 ml (P less than 0.0001) and 317 +/- 20 ml (P less than 0.0001), respectively, while transhepatic vascular resistance increased 17 +/- 4 cm H2O X min/l (P less than 0.0001). These responses were abolished after alpha adrenergic blockade. Thus, splanchnic volume decreases with alpha adrenergic receptor stimulation, despite an increase in hepatic resistance to splanchnic venous outflow. The splanchnic volume decrement is entirely responsible for the total volume decrement.

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Influence of naloxone on the total capacitance vasculature of the dog.

Cited by 7 publications

References 21 publications

Hormonal responses to opioid receptor blockade: during rest and exercise in cold and hot environments

Hormonal responses to opioid receptor blockade: during rest and exercise in cold and hot environments

Influence of angiotensin on total intravascular capacity in the anaesthetized pig

The role of the splanchnic circulation in the regulation of total intravascular volume during alpha adrenergic receptor stimulation

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