Validity Studies of the Radioactive Microsphere Method for the Study of the Distribution of Cardiac Output, Organ Blood Flow, and Resistance in the Conscious Rhesus Monkey

1969 ◽  
Vol 3 (4) ◽  
pp. 426-432 ◽  
Author(s):  
B. I. Hoffbrand ◽  
R. P. Forsyth
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Rhesus Monkey ◽  
Organ Blood Flow ◽  
Radioactive Microsphere ◽  
Microsphere Method ◽  
Radioactive Microsphere Method ◽  
Validity Studies ◽  
Distribution Of Cardiac Output

Hemodynimic effects of systemic and central administration of clonidine in the monkey

1975 ◽  
Vol 228 (4) ◽  
pp. 1276-1279 ◽  
Author(s):  
P Bolme ◽  
RP Forsyth ◽  
T Ishizaki ◽  
KL Melmon
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Systemic Arterial Pressure ◽  
Intraventricular Injection ◽  
Central Administration ◽  
New Information ◽  
Before And After ◽  
Microsphere Method ◽  
Radioactive Microsphere Method

Systemic and regional hemodynamic changes were measured in restrained, conscious rhesus monkeys with indwelling arterial and venous catheters before and after clonidine (5 and 15 mug/kg) was slowly infused intravenously or smaller doses (2 mug/kg) were injected into a lateral cerebral ventricle. Dye-dilution cardiac outputs and the complete distribution of cardiac output were obtained intermittently with the use of the radioactive microsphere method. After the higher intravenous dose and the intraventricular injection, systemic arterial pressure was significantly lowered for 30-45 min. Both of these groups had similar changes in the redistribution of cardiac output and blood flow that outlasted the hypotensive period. Blood flow was maintained or increased in the hepatic and renal arteries at the expense of skin; flow to skeletal muscle and brain also decreased during the first hour. These data support previous studies that indicate that the primary action of clonidine is in the central nervous system and, in addition, add new information about the regional blood flow changes evoked by clonidine.

Cardiac output and organ blood flow in warm- and cold-acclimated rats exposed to cold

1968 ◽  
Vol 46 (4) ◽  
pp. 653-659 ◽  
Author(s):  
L. Jansky ◽  
J. S. Hart
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Skeletal Muscles ◽  
Organ Blood Flow ◽  
Internal Organs ◽  
Exposure To Cold ◽  
Brown Adipose ◽  
Production Increase ◽  
Distribution Of Cardiac Output ◽  
Fractional Distribution

Cold acclimation increased the cardiac output of unanesthetized rats when measured at 30 °C. After exposure to 9 °C for 70 min cardiac output further increased by 46% in both warm- and cold-acclimated rats. From the changes in the fractional distribution of cardiac output after cold exposure it was shown that the blood flow increased significantly in muscular organs (heart, diaphragm, skeletal muscles) and in the adrenals of warm-acclimated rats. In cold-acclimated rats the blood flow to the brown and white adipose tissues, pancreas, kidney, intestine, liver, and other internal organs was also increased in a cold environment, and accounted for 65% of the increase in blood flow during exposure to cold compared with only 36% in warm-acclimated rats. It is estimated that the extramuscular thermogenesis can account for a greater proportion of the total nonshivering thermogenesis in cold-acclimated rats. The contribution of brown adipose tissue is estimated not to exceed about 6% of the total heat production increase in cold-acclimated rats during exposure to cold.

A Simple Radioactive Microsphere Method for Measuring Regional Flow and Cardiac Output

1974 ◽  
Vol 9 (3) ◽  
pp. 126-132 ◽  
Author(s):  
Royal J. Bartrum ◽  
Daniel M. Berkowitz ◽  
Norman K. Hollenberg
Keyword(s):  
Cardiac Output ◽  
Regional Flow ◽  
Radioactive Microsphere ◽  
Microsphere Method ◽  
Radioactive Microsphere Method

Canine gastric blood flow and its distribution

1964 ◽  
Vol 207 (6) ◽  
pp. 1195-1202 ◽  
Author(s):  
John P. Delaney ◽  
Eugene Grim
Keyword(s):  
Blood Flow ◽  
Gastric Blood Flow ◽  
Total Flow ◽  
Venous Outflow ◽  
Radioactive Microsphere ◽  
Venous Catheterization ◽  
Microsphere Method ◽  
Radioactive Microsphere Method ◽  
Clearance Technique

Total gastric blood flow in the dog as estimated by the K42 clearance technique agreed within 5% with measured total venous outflow. Extraction of the isotope by the stomach was found to be such that 30–60 sec following injection the organ contained a fraction of the injected dose that was the same as the fraction of the cardiac output that perfused the organ. By comparison with the radioactive microsphere method, the K42 clearance technique was also found to be reasonably accurate for determination of the distribution of the total flow within the organ. Mean total gastric blood flow in intact dogs, unoperated upon except for femoral arterial and venous catheterization, was 49 ml/min per organ or 0.54 ml/min per gram. This was distributed 80% to corpus and 20% to antrum. The corpus flow was partitioned among the mural tissues: mucosa 72%, submucosa 13%, and muscle serosa 15%.

Role of EDRF in splanchnic blood flow of normal and chronic portal hypertensive rats

1992 ◽  
Vol 263 (2) ◽  
pp. G149-G154 ◽  
Author(s):  
F. Iwata ◽  
T. Joh ◽  
T. Kawai ◽  
M. Itoh
Keyword(s):  
Blood Flow ◽  
Splanchnic Blood Flow ◽  
Constant Infusion ◽  
Relaxing Factor ◽  
Radioactive Microsphere ◽  
Blood Flow Reduction ◽  
Microsphere Method ◽  
Radioactive Microsphere Method ◽  
Endothelium Derived Relaxing Factor

The role of endogenous endothelium-derived relaxing factor (EDRF) in splanchnic blood flow was assessed in normal and portal vein-stenosed rats (PSRs). Specific and maximal inhibition of EDRF was achieved by intravenous administration of NG-nitro-L-arginine (L-NOARG) as a 1.75 mumol/kg bolus, followed by constant infusion of 1.75 mumol/kg for 20 min. Pretreatment with L-arginine (175 mumol/kg iv) completely blocked both hypertension and the reduction in blood flow induced by L-NOARG. Pretreatment with D-arginine (175 mumol/kg iv) and prazosin (500 micrograms/kg iv) did not attenuate the pressor effect of L-NOARG. These results indicate that L-NOARG selectively blocks EDRF. The blood flow to the stomach, duodenum, jejunum, ileum, cecum, and colon in control rats was 81.1 +/- 8.7, 199.1 +/- 21.9, 153.3 +/- 20.0, 68.6 +/- 10.6, 79.4 +/- 11.8, and 59.3 +/- 7.8 ml.min-1.100 g-1, respectively, and in PSRs was 141.4 +/- 10.8, 244.0 +/- 10.4, 208.3 +/- 9.8, 126.8 +/- 13.0, 166.9 +/- 16.5, and 94.8 +/- 4.7 ml.min-1.100 g-1, respectively. Blood flow was measured using the radioactive microsphere method. L-NOARG significantly reduced blood flow to the stomach, duodenum, jejunum, ileum, cecum, and colon in control rats by 47, 44, 48, 55, 40, and 41%, respectively, and in PSRs by 30, 27, 36, 33, 28, and 23%, respectively. The magnitude of blood flow reduction in PSRs was lower than in normal rats. These results indicate that EDRF plays an important role in control of the splanchnic circulation, but its effect on the hyperdynamic circulation observed in PSRs is insignificant.

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