Effect of aldosterone and of plasma extracts on a rat heart-lung preparation

1960 ◽  
Vol 199 (2) ◽  
pp. 221-225 ◽  
Author(s):  
Kathryn Ballard ◽  
Allan Lefer ◽  
George Sayers

Heart-lungs from intact rats were perfused with blood from intact rats (intact-intact preparations) or with blood from adrenalectomized rats (intact-adrenalectomized preparations). Left ventricular work index (LVWI) was employed to evaluate performance of the heart-lung and calculated as the product of cardiac output and mean arterial blood pressure. In confirmation of a previous report from this laboratory, LVWI was less for intact-adrenalectomized preparations than for intact-intact preparations. Aldosterone, added to perfusion blood from adrenalectomized rats to make a concentration of 2 x 10–3, 8 x 10–3 or 3.2 x 10–2 µg/100 ml, increased LVWI of the intact-adrenalectomized preparation to that of the intact-intact preparation. Extracts of plasma from intact rats, which may be expected to contain corticosteroids, were also capable of increasing LVWI of the intact-adrenalectomized preparation. Extracts of plasma from adrenalectomized rats were inactive.

1963 ◽  
Vol 44 (3) ◽  
pp. 430-442 ◽  
Author(s):  
B. Arner ◽  
P. Hedner ◽  
T. Karlefors ◽  
H. Westling

ABSTRACT Observations were made on healthy volunteers during insulin induced hypoglycaemia (10 cases) and infusion of adrenaline (3 cases) or cortisol (1 case). In all cases a rise in the cardiac output was registered during insulin hypoglycaemia. The mean arterial blood pressure was relatively unchanged and the calculated peripheral vascular resistance decreased in all cases. A temporary rise in plasma corticosteroids was observed. After infusion of adrenaline similar circulatory changes were observed but no rise in plasma corticosteroids was found. Infusion of cortisol caused an increased plasma corticosteroid level but no circulatory changes. It is concluded that liberation of catechol amines and increased adrenocortical activity following hypoglycaemia are not necessarily interdependent.


1991 ◽  
Vol 261 (1) ◽  
pp. H172-H180 ◽  
Author(s):  
L. M. Sassen ◽  
K. Bezstarosti ◽  
W. J. Van der Giessen ◽  
J. M. Lamers ◽  
P. D. Verdouw

Effects of pretreatment with L-propionylcarnitine (50 mg/kg, n = 9) or saline (n = 10) were studied in open-chest anesthetized pigs, in which ischemia was induced by decreasing left anterior descending coronary artery blood flow to 20% of baseline. After 60 min of ischemia, myocardium was reperfused for 2 h. In both groups, flow reduction abolished contractile function of the affected myocardium and caused similar decreases in ATP (by 55%) and energy charge [(ATP + 0.5ADP)/(ATP + ADP + AMP); decrease from 0.91 to 0.60], mean arterial blood pressure (by 10-24%), the maximum rate of rise in left ventricular pressure (by 26-32%), and cardiac output (by 20-30%). During reperfusion, “no-reflow” was attenuated by L-propionylcarnitine, because myocardial blood flow returned to 61 and 82% of baseline in the saline- and L-propionylcarnitine-treated animals, respectively. Cardiac output of the saline-treated animals further decreased (to 52% of baseline), and systemic vascular resistance increased from 46 +/- 3 to 61 +/- 9 mmHg.min.l-1, thereby maintaining arterial blood pressure. In L-propionylcarnitine-treated pigs, cardiac output remained at 75% of baseline, and systemic vascular resistance decreased from 42 +/- 3 to 38 +/- 4 mmHg.min.l-1. In both groups, energy charge but not the ATP level of the ischemic-reperfused myocardium tended to recover, whereas the creatine phosphate level showed significantly more recovery in saline-treated animals. We conclude that L-propionylcarnitine partially preserved vascular patency in ischemic-reperfused porcine myocardium but had no immediate effect on “myocardial stunning.” Potential markers for long-term recovery were not affected by L-propionylcarnitine.


1995 ◽  
Vol 78 (5) ◽  
pp. 1793-1799 ◽  
Author(s):  
M. Kamitomo ◽  
T. Ohtsuka ◽  
R. D. Gilbert

We exposed fetuses to high-altitude (3,820 m) hypoxemia from 30 to 130 days gestation, when we measured fetal heart rate, right and left ventricular outputs with electromagnetic flow probes, and arterial blood pressure during an isoproterenol dose-response infusion. We also measured the distribution of cardiac output with radiolabeled microspheres during the maximal isoproterenol dose. Baseline fetal arterial blood pressure was higher in long-term hypoxemic fetuses (50.1 +/- 1.3 vs. 43.4 +/- 1.0 mmHg) but fell during the isoproterenol infusion to 41.3 +/- 1.4 and 37.5 +/- 1.4 mmHg, respectively, at the highest dose. Heart rate was the same in both groups and did not differ during isoproterenol infusion. Baseline fetal cardiac output was lower in the hypoxemic group (339 +/- 18 vs. 436 +/- 19 ml.min-1.kg-1) due mainly to a reduction in right ventricular output. During the isoproterenol infusion, right ventricular output increased to the same extent in both hypoxemic and normoxic fetuses (approximately 35%); however, left ventricular output increased only approximately 15% in the hypoxemic group compared with approximately 40% in the normoxic group. The percent change in individual organ blood flows during isoproterenol infusion in the hypoxemic groups was not significantly different from the normoxic group. All of the mechanisms that might be responsible for the differential response of the fetal left and right ventricles to long-term hypoxia are not understood and need further exploration.


1979 ◽  
Vol 57 (5) ◽  
pp. 995-1002 ◽  
Author(s):  
David R. Jones ◽  
Robert M. Bryan Jr. ◽  
Nigel H. West ◽  
Raymond H. Lord ◽  
Brenda Clark

The regional distribution of blood flow, both before and during forced diving, was studied in the duck using radioactively labelled microspheres. Cardiac output fell from 227 ± 30 to 95 ± 16 mL kg−1 min−1 after 20–72 s of submergence and to 59 ± 18 mL kg−1 min−1 after 144–250 s of submergence. Mean arterial blood pressure did not change significantly as total peripheral resistance increased by four times during prolonged diving. Before diving the highest proportion of cardiac output went to the heart (2.6 ± 0.5%, n = 9) and kidneys (2.7 ± 0.5%, n = 9), with the brain receiving less than 1%. The share of cardiac output going to the brain and heart increased spectacularly during prolonged dives to 10.5 ± 3% (n = 5) and 15.9 ± 3.8% (n = 5), respectively, while that to the kidney fell to 0.4 ± 0.26% (n = 3). Since cardiac output declined during diving, tissue blood flow (millilitres per gram per minute) to the heart was unchanged although in the case of the brain it increased 2.35 times after 20–75 s of submergence and 8.5 times after 140–250 s of submergence. Spleen blood flow, the highest of any tissue predive (5.6 ± 1.3 mL g−1 min−1, n = 4), was insignificant during diving while adrenal flow increased markedly, in one animal reaching 7.09 mL g−1 min−1. The present results amplify general conclusions from previous research on regional distribution of blood flow in diving homeotherms, showing that, although both heart and brain receive a significant increase in the proportionate share of cardiac output during diving only the brain receives a significant increase in tissue blood flow, which increases as submergence is prolonged.


1984 ◽  
Vol 247 (2) ◽  
pp. R266-R271
Author(s):  
D. L. Crandall ◽  
B. M. Goldstein ◽  
R. A. Gabel ◽  
P. Cervoni

The effect of defined increments of weight loss on hemodynamics has been investigated in conscious, unrestrained, spontaneously obese rats. Obese rats were subjected to a calorically restricted diet and were used for experimentation on achieving a 10, 20, or 30% reduction in body weight. After monitoring resting blood pressure and heart rate, radioactive microspheres were infused for determination of blood flow distribution. Of 10 organs sample, only heart, liver, kidneys, and 2 adipose tissue depots exhibited significant decreases in weight associated with body weight reduction. Mean arterial blood pressure remained unchanged, while stroke volume, left ventricular work, and cardiac output decreased significantly. Blood flow decreased to kidneys, testes, and adipose tissue through a 30% reduction in body weight, but the fractional distribution of cardiac output decreased only to adipose tissue. Therefore the large decreases in renal and adipose tissue blood flow during weight reduction may contribute to the associated decrease in cardiac output. Of those vascular beds examined, however, both absolute and relative blood flow decreased only to adipose tissue, thus denoting the influence of fat mass on hemodynamics during obesity.


1950 ◽  
Vol 163 (1) ◽  
pp. 135-140 ◽  
Author(s):  
René Wégria ◽  
Charles W. Frank ◽  
George A. Misrahy ◽  
Robert S. Sioussat ◽  
Leonard S. Sommer ◽  
...  

1958 ◽  
Vol 192 (2) ◽  
pp. 345-352 ◽  
Author(s):  
W. J. Roberson ◽  
Steven M. Horvath

Twelve experiments were conducted on anesthetized and paired dogs of similar weights subjected to unimpeded, unregulated crossed circulation. Shunts were made between the carotid arteries and external jugular veins and free flow allowed for 60 minutes or longer. Statistically significant changes occurred in the mean femoral arterial blood pressures, carotid shunt blood flow, heart rate, cardiac output, cardiac work, percentage of cardiac output flowing through the shunt and pulmonary systolic and diastolic pressures of one or both animals from their control values. The mean arterial blood pressure remained at control levels for several minutes and then dropped precipitously to hypotensive levels. The lowest mean pressures between 42 and 49 mm Hg occurred within the first 16.5 minutes of the open shunt phase with a gradual return toward control levels. The volume of blood flowing through the shunt was increased initially 250% above the control carotid blood flow, followed by a reduction in flow after 15 minutes; the volume flow at this moment was still double precross circulation levels. A secondary increase in the shunt blood flow occurred throughout the remainder of the open shunt phase. In general, the heart rates and peripheral vascular resistance were slightly elevated during the open shunt phase while cardiac output and work decreased below their control values. A marked and similar increase in the percentage of the cardiac output flowing through the carotid artery was observed in both animals. During the 60 minutes of the recovery period mean arterial blood pressure, cardiac output and work tended to return to control levels while the carotid artery blood flow and pulmonary systolic and diastolic pressure remained slightly below their control values.


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