Influence of volume of food intake on blood flow in the portal vein and the clearance of progesterone from plasma in gilts

1989 ◽  
Vol 1989 ◽  
pp. 13-13
Author(s):  
H.W. Symonds ◽  
G. Prime
Keyword(s):  
Blood Flow ◽  
Food Intake ◽  
Portal Vein ◽  
Jugular Vein ◽  
Vena Cava ◽  
Early Embryo ◽  
Metabolic Clearance ◽  
Priming Dose ◽  
Metabolic Clearance Rate ◽  
Flow Through

One hypothesis for the adverse effect which a high food intake in early pregnancy has on early embryo mortality in gilts is that it increases blood flow through the liver and in consequence the rate of removal of progesterone from the blood. To study this aspect the metabolic clearance rate of progesterone (MCR) from plasma and the rate of blood flow in the portal vein were measured concurrently during 14 hour periods in six ovariectomised gilts, weighing 70 to 80 kg, when their food intake was 1 and 3 kg/day. To determine the MCR, progesterone was infused into a jugular vein at 70 ug/minute for 36 hours. The concentration of progesterone was determined in plasma samples collected from a cannula in the posterior vena cava at 20 minute intervals during the last 14 hours of infusion when an equilibrium had established between the rates of infusion and clearance. Because ovariectomy removed the principal endogenous source of progesterone, body fat became depleted of the steroid. Therefore, a priming dose of approximately 100 mg of progesterone in arachis oil was given intramuscularly 48 and 24 hours before each infusion started.

Influence of plane of nutrition on portal blood flow and the metabolic clearance rate of progesterone in ovariectomized gilts

1993 ◽  
Vol 121 (3) ◽  
pp. 389-397 ◽  
Author(s):  
G. R. Prime ◽  
H. W. Symonds
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Food Intake ◽  
Portal Vein ◽  
Portal Blood Flow ◽  
Weight Basis ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Total Hepatic Blood Flow ◽  
The Mean

SUMMARYThe effects of plane of nutrition on blood flow in the portal vein (PBF) and on the rate of clearance of progesterone from the circulation (MCR) were measured for 14 or 24 h in six ovariectomized gilts given 1 or 3 kg of food per day. On a body weight basis, PBF was significantly increased by the increase in food intake from a mean for all gilts of 14·9 ml/kg.min (1·34 litres/min) on 1 kg to 21·6 ml·kg. min (1·96 litres/min) on 3 kg, a mean increase of 45 %. Metabolic clearance of progesterone was increased by a similar percentage, 47·1%, from 41·0 ml/kg.min (3·70 litres/min) to 60·3 ml/kg.min (5·67 litres/min) by the increase in food intake. Both MCR and PBF were lowest between 04.00 and 06.00 h, increasing after each feed except that when 3 kg/day was fed the MCR remained high throughout the period between meals. In two gilts, blood flow in both the portal vein and hepatic artery (HAF) was measured. The mean PBF and HAF for each pig were 40·6 and 5·8, and 32·4 and 35 ml/kg, min respectively. HAF was 11·2% of total hepatic blood flow.

Glucagon and insulin metabolism in a portal-hypertensive rat model

1987 ◽  
Vol 253 (2) ◽  
pp. G110-G115 ◽  
Author(s):  
E. Sikuler ◽  
J. Polio ◽  
R. J. Groszmann ◽  
R. Hendler
Keyword(s):  
Portal Vein ◽  
Rat Model ◽  
Clearance Rate ◽  
Portal Blood Flow ◽  
Portal System ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Insulin Metabolism ◽  
Portosystemic Shunting ◽  
Glucagon And Insulin

The role that portosystemic shunting plays in inducing the alterations of glucagon and insulin metabolism, which are observed in chronic liver disease, was studied in a rat model of prehepatic portal hypertension induced by portal vein constriction. Net splanchnic output of the hormones into the portal circulation was calculated from the difference between portal and systemic concentrations multiplied by portal plasma flow. Metabolic clearance rate was calculated as the ratio between output and systemic concentration. Portal blood flow was measured by the radioactive microsphere technique. Glucagon output in the portal vein-ligated rats was higher than in the sham-operated controls (5.9 +/- 1.5 vs. 2.0 +/- 0.2 ng/min, P less than 0.05). The metabolic clearance rate of glucagon was not significantly different between the two groups. Insulin output was not significantly different between the two groups; however, the metabolic clearance rate of insulin in the portal vein-ligated rats was reduced in comparison with the sham-operated group (9.5 +/- 1.5 vs. 18.4 +/- 3.3 ml/min, P less than 0.05). Our results indicate that portosystemic shunting per se is sufficient to cause an increased splanchnic output of glucagon into the portal system and a decreased metabolic clearance of insulin.

A Comparative Study on the Metabolism of Human Insulin and Porcine Proinsulin in Man

1973 ◽  
Vol 45 (5) ◽  
pp. 633-654 ◽  
Author(s):  
P. H. Sönksen ◽  
Christine V. Tompkins ◽  
M. C. Srivastava ◽  
J. D. N. Nabarro
Keyword(s):  
Human Insulin ◽  
Normal Subjects ◽  
Constant Infusion ◽  
Metabolic Clearance ◽  
Priming Dose ◽  
Metabolic Clearance Rate ◽  
Serum Growth Hormone ◽  
Biological Potency ◽  
Infusion Technique ◽  
Apparent Distribution

1. The metabolism of unlabelled monocomponent human insulin and porcine proinsulin was studied in ten normal subjects (five males and five females) by using a priming dose-constant-infusion technique. In each subject, the metabolic clearance rate (MCR) was measured at four separate steady-state hormone concentrations averaging 16–216 μunits/ml (insulin) and 4·2–42·8 ng/ml (proinsulin). 2. For insulin the MCR fell progressively from 34 ml kg−1 min−1 at a mean fasting insulin concentration of 3·8 μunits/ml to 11·4 ml kg−1 min−1 at the highest concentration achieved (280 μunits/ml); for proinsulin MCR averaged 3·7 ml kg−1 min−1 at a mean plasma concentration of 4·2 ng/ml and fell to 2·71 ml kg−1 min−1 at 10·7 ng/ml, remaining constant thereafter at concentrations up to 71 ng/ml. 3. The half-disappearance time (T½) from the plasma, after the end of the infusion, averaged 4·3 min for insulin and 25·6 min for proinsulin. 4. The apparent distribution space (DS) was similar for both hormones (83 ml/kg of insulin and 98·9 ml/kg of proinsulin). 5. There was a direct correlation between T½ and DS for both hormones. 6. Although the higher MCR of insulin was reflected in its shorter T½ there was, for each hormone, no relationship between MCR and T½. 7. The biological potency of porcine proinsulin, as judged by its effect on plasma glucose, was approximately 5% of that of insulin. 8. The responses of serum growth hormone and Cortisol were shown to be directly related to the degree of hypoglycaemia induced.

scholarly journals Effects of infusions of lysine, leucine and ammonium chloride into the hepatic portal vein of chickens on voluntary food intake

1987 ◽  
Vol 58 (2) ◽  
pp. 325-331 ◽  
Author(s):  
Audrey A. Rusby ◽  
J. M. Forbes
Keyword(s):  
Food Intake ◽  
Portal Vein ◽  
Ammonium Chloride ◽  
Jugular Vein ◽  
Free Access ◽  
Delayed Effect ◽  
Hepatic Portal Vein ◽  
Hepatic Portal ◽  
Access To Food ◽  
Portal Infusion

1. Adolescent cockerels of a laying strain were prepared with catheters whose tip lay in the hepatic portal vein, to study the effect of 3-h infusions of nutrients on food intake.2. Lysine, infused into the hepatic portal vein at rates of 150–450 mg/3 h reduced 3-h food intake by up to 58%, for a period of 6 h in previously starved birds, but had no effect on birds allowed free access to food. Infusions made into the jugular vein had no effect, suggesting a role for the liver in monitoring lysine levels.3. Portal infusion of leucine had a delayed effect while ammonium chloride, infused at isomolar rates to those of the lysine infusions, had very little effect on intake.4. The results support the concept of liver sensitivity to amino acids, but the mode of action is not clear; it appears not to be via the effects of ammonia.

Endovascular stenting of mesenterico-portal vein stenosis to reduce blood flow through venous collaterals prior to pancreatoduodenectomy

2015 ◽  
Vol 400 (5) ◽  
pp. 629-631 ◽  
Author(s):  
Terence C. Chua ◽  
Frank Wang ◽  
Richard Maher ◽  
Sivakumar Gananadha ◽  
Anubhav Mittal ◽  
...  
Keyword(s):  
Blood Flow ◽  
Portal Vein ◽  
Endovascular Stenting ◽  
Reduce Blood Flow ◽  
Portal Vein Stenosis ◽  
Venous Collaterals ◽  
Flow Through ◽  
Vein Stenosis

Blood flow through vasa vasorum in arteries and veins: effects of luminal PO2

1986 ◽  
Vol 250 (3) ◽  
pp. H434-H442 ◽  
Author(s):  
D. D. Heistad ◽  
M. L. Armstrong ◽  
S. Amundsen
Keyword(s):  
Blood Flow ◽  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Superior Vena ◽  
Acute Hypoxia ◽  
Vena Cava ◽  
Vasa Vasorum ◽  
Aortic Media ◽  
Flow Through ◽  
Arteries And Veins

We have examined effects of chronic reduction of intraluminal PO2 on blood flow through vasa vasorum, by comparing large arteries and veins, and effects of acute hypoxia on flow through vasa. Microspheres were used to measure flow in anesthetized dogs. Values obtained with different sizes of microspheres suggest that spheres 9 and 15 micron in diam, but not 50 micron, are appropriate for measurement of blood flow through vasa vasorum. Flow [expressed as ml X min-1 X 100 g-1 (SE)] through medial vasa was similar in the aorta (9.0 +/- 2.1) and pulmonary artery (9.3 +/- 1.1) although, on the basis of wall thickness and number of lamellae, one would predict much higher levels of flow to aortic media. Two veins that we studied have a thick muscular wall. Both veins had high levels of flow through medial vasa: 33 +/- 4.4 to the subdiaphragmatic inferior vena cava and 18 +/- 5.4 to the portal vein. Two other veins are apparently conduit vessels, with dense connective tissue and minimal smooth muscle. Both veins had minimal flow through medial vasa: 2.4 +/- 1.0 to superior vena cava, and 1.9 +/- 0.8 to supradiaphragmatic inferior vena cava. Thus, because flow through vasa differs greatly in different veins, structure of the vessel (as well as intraluminal PO2) is an important determinant of flow through vasa. Acute hypoxia increased conductance of medial vasa vasorum of arteries and veins when neurohumoral constrictor effects were blocked by phenoxybenzamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Is the beneficial effect of prior exercise on postprandial lipaemia partly due to redistribution of blood flow?

2011 ◽  
Vol 120 (12) ◽  
pp. 537-548 ◽  
Author(s):  
Nicholas M. Hurren ◽  
George M. Balanos ◽  
Andrew K. Blannin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Portal Vein ◽  
High Fat ◽  
Postprandial Lipaemia ◽  
Postprandial Period ◽  
Hepatic Portal Vein ◽  
Flow Through ◽  
Hepatic Portal

Preprandial aerobic exercise lowers postprandial lipaemia (a risk factor for coronary heart disease); however, the mechanisms responsible are still not clear. The present study investigated whether blood flow to skeletal muscle and/or the liver was increased in the postprandial period after exercise, relative to a control trial, and whether this resulted from increased cardiac output or redistribution of flow. Eight overweight inactive males, aged 49.4±10.5 years (mean±S.D.), acted as their own controls in a counterbalanced design, either walking briskly for 90 min at 60% V̇O2max (maximal oxygen uptake), or resting in the lab, on the evening of day 1. The following morning, a fasting blood sample was collected, participants consumed a high-fat breakfast, and further venous blood samples were drawn hourly for 6 h. Immediately after blood sampling, Doppler ultrasound was used to measure cardiac output and blood flow through both the femoral artery of one leg and the hepatic portal vein, with the ultrasonographer blinded to trial order. The total postprandial triacylglycerol response was 22% lower after exercise (P=0.001). Blood flow through the femoral artery and the hepatic portal vein was increased by 19% (P<0.001) and 16% (P=0.033), respectively, during the 6-h postprandial period following exercise; however, postprandial cardiac output did not differ between trials (P=0.065). Redistribution of blood flow, to both exercised skeletal muscle and the liver, may therefore play a role in reducing the plasma triacylglycerol response to a high-fat meal on the day after an exercise bout.

Increase of cerebral blood flow produced by low dosages of cyanide

1963 ◽  
Vol 204 (2) ◽  
pp. 309-313 ◽  
Author(s):  
Mauricio Russek ◽  
Adolfo Fernandez F. ◽  
Cordelia Vega
Keyword(s):  
Blood Flow ◽  
Hind Limb ◽  
Jugular Vein ◽  
Great Increase ◽  
Femoral Vein ◽  
Sagittal Sinus ◽  
Flow Through ◽  
Significant Change ◽  
The Brain ◽  
Oxygen Difference

In cats and rabbits lightly anesthetized with pentobarbital or immobilized with Flaxedil and in encéphale isolé cats, the intravenous injection of NaCN in doses of 0.05 to 0.5 mg/kg produced a great increase in blood flow from the head (jugular vein) without any significant change in the blood flow from a hind limb (femoral vein). This would indicate that the increase in blood flow from the head was probably due to the brain and not to the nonnervous structures. This assumption was further supported by the large increase in the blood flow through the sagittal sinus. The greatest increase in jugular flow, threefold, was produced by 0.2–0.3 mg/kg of cyanide. This dose did not produce any significant change in the arterial, jugular, and femoral vein oxygen concentration, and hence in the A-V oxygen difference of head and limb. The results would indicate that the consumption of the brain is augmented by these dosages of cyanide.

METABOLIC CLEARANCE RATE, PRODUCTION RATE, AND MAMMARY UPTAKE AND METABOLISM OF PROGESTERONE IN COWS

1975 ◽  
Vol 66 (2) ◽  
pp. 239-247 ◽  
Author(s):  
R. B. HEAP ◽  
A. HENVILLE ◽  
J. L. LINZELL
Keyword(s):  
Production Rate ◽  
Clearance Rate ◽  
Jugular Vein ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Tracer Kinetic ◽  
The Mean ◽  
Jersey Cows ◽  
Conscious Animals ◽  
Uptake And Metabolism

SUMMARY Tracer kinetic techniques have been used to measure the production rate, metabolic clearance rate and mammary uptake of progesterone in six experiments on two Jersey cows. The cows were surgically prepared so that the carotid artery, jugular vein and mammary vein concentrations of progesterone, and udder blood flow, could be determined in conscious animals without anaesthesia or stress. The mean production rate of progesterone was 173 ± 23·3 (s.e.m.) μg/min, with values ranging from 80 to 276 μg/min in pregnancy. The metabolic clearance rate was 22·5 ± 2·0 1/min, or 0·21 ± 0·025 1/min/kg metabolic body weight. The mammary uptake of progesterone was low, 3·1 ± 1·1 μg/min, and udder uptake accounted for about 3% of progesterone production rate. During [3H]progesterone infusion, radioactivity was transferred from blood to milk, probably by diffusion down a concentration gradient. Progesterone accounted for more than 88% of the ether-soluble radioactivity recovered from milk.

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