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

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.

Author(s):  
H.W. Symonds ◽  
G. Prime

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.


1987 ◽  
Vol 253 (2) ◽  
pp. G110-G115 ◽  
Author(s):  
E. Sikuler ◽  
J. Polio ◽  
R. J. Groszmann ◽  
R. Hendler

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.


1975 ◽  
Vol 34 (1) ◽  
pp. 125-139 ◽  
Author(s):  
A. J. F. Webster ◽  
P. O. Osuji ◽  
F. White ◽  
J. F. Ingram

1. Measurements were made of portal blood flow, heat production and oxygen consumption in the digestive tract of sheep either fasted or given the following diets: chopped, dried grass; pelleted, dried grass; chopped, dried lucerne; pelleted, dried lucerne; or a pelleted baley diet.2. For sheep that had been fasted for 48 h, portal blood flow was 1.84 1/min, total visceral heat production was 62.3 kJ/kg body-weight0.75 per 24 h and aerobic heat production, estimated from oxygen consumption, was 62.1 kJ/kg body-weight0.75 per 24 h.3. Portal blood flow was markedly influenced by food intake, increasing from 1.8 1/min for starved sheep to 2.4 and 4 1/min for sheep fed at maintenance and 2.5 × maintenance levels of intake respectively. Variations in the quality and physical form of the diets had no apparent effect on portal blood flow.4. There was a curvilinear relationship between total heat production in the gut and metabolizable energy (ME) intake. The increase obtained for levels of intake below maintenance was greatest with lucerne diets, and least with pelleted, dried grass or pelleted barley diets. Above maintenance levels of intake the rate of increase in heat production, with all diets, was about 150 kJ/MJ ME intake.5. The heat of fermentation, estimated from the difference between total visceral metabolism and the aerobic metabolism of the tissues of the gut wall, was 76, 60 and 22 kJ/MJ digestible energy intake for the dried grass, lucerne and barley diets respectively.6. The contribution of fermentation heat and the aerobic metabolism of the gut to the total heat increment of feeding in sheep was assessed. It was concluded that about half the heat increment must be derived from tissues outside the digestive tract.


2021 ◽  
pp. 002367722110003
Author(s):  
Kristoffer Kjærgaard ◽  
Michael Sørensen ◽  
Frank Viborg Mortensen ◽  
Aage Kristian Olsen Alstrup

The liver receives dual blood supply from the hepatic artery and portal vein. The pig is often used as an animal model in positron emission tomography (PET) and pharmacokinetic studies because of the possibility for extensive and direct blood sampling. In this study, we compared measurements of hepatic blood flow in 10 female adult Göttingen minipigs and 10 female pre-pubertal Danish Landrace x Yorkshire (DLY) pigs. Ultrasound transit time flow meter probes were placed around the hepatic artery and portal vein through open surgery, hepatic blood flow measurements were performed, and the liver was weighed. Total hepatic blood flow was on average 363 ± 131 mL blood/min in Göttingen minipigs and 988 ± 180 mL blood/min in DLY pigs ( p < 0.001). The mean hepatic blood perfusion was 623 mL blood/min/mL liver tissue and 950 mL blood/min/mL liver tissue ( p = 0.005), and the liver weight was 0.58 kg and 1.04 kg, respectively. The mean arterial flow fraction in Göttingen minipigs was 12 ± 7% and lower than in DLY pigs, where it was 24 ± 7% ( p = 0.001). Using the gold standard for blood flow measurements, we found that both total hepatic blood flow and blood perfusion were significantly lower in Göttingen minipigs than in DLY pigs. The hepatic blood perfusion and arterial flow fraction in DLY pigs were comparable to normative values from humans. Differences in hepatic blood flow between adult Göttingen minipigs and humans should be considered when performing physiological liver studies in this model.


1987 ◽  
Vol 65 (8) ◽  
pp. 1762-1779 ◽  
Author(s):  
Simon Gelman

This article describes hepatic circulatory disturbances associated with anesthesia and surgical intervention. The material is presented in three parts: part 1 describes the effects of general anesthetics on the hepatic circulation; part 2 deals with different factors related to surgical procedures and anesthesia; and part 3 analyzes the role of hepatic circulatory disturbances and hepatic oxygen deprivation in anesthesia-induced hepatotoxicity. The analysis of available data suggests that general anesthesia affects the splanchnic and hepatic circulation in various directions and to different degrees. The majority of anesthetics decreases portal blood flow in association with a decrease in cardiac output. However, hepatic arterial blood flow can be preserved, decreased, or increased. The increase in hepatic arterial blood flow, when it occurs, is usually not enough to compensate for a decrease in portal blood flow and therefore total hepatic blood flow is usually decreased during anesthesia. This decrease in total hepatic blood flow-has certain pharmacokinetic implications, namely a decrease in clearance of endogenous and exogenous substances with a high hepatic extraction ratio. On the other hand, a reduction in the hepatic oxygen supply might play a certain role in liver dysfunction occurring perioperatively. Surgical procedures–preparations combined with anesthesia have a very complex effect on the splanchnic and hepatic circulation. Within this complex, the surgical procedure–preparation plays the main role in developing circulatory disturbances, while anesthesia plays only a modifying role. Hepatic oxygen deprivation may play an important role in anesthesia-induced hepatotoxicity in different experimental models.


2017 ◽  
Vol 37 (10) ◽  
pp. 1172-1176 ◽  
Author(s):  
Alexandra F. Belotta ◽  
Bianca P. Santarosa ◽  
Danilo O.L. Ferreira ◽  
Sílvia M.F. Carvalho ◽  
Roberto C. Gonçalves ◽  
...  

ABSTRACT: Pulsed Doppler ultrasound was used to evaluate portal blood flow, portal velocity and portal congestion index in 24 healthy sheep divided into groups (lambs, yearlings and ewes), according to age. Measurements were performed at the 11th right intercostal space using ideal insonation angle and uniform insonation method. Mean values obtained in each group were compared with one-way ANOVA, followed by Tukey post-hoc test. Portal velocity and portal blood flow were statistically similar between the groups (P>0.05). Mean portal velocity were 17.75; 17.13 and 16.75; while mean portal blood flow were 26.65; 31.04 and 24.32 for lambs, yearlings and ewes, respectively. Portal congestion index was statistically distinct between the groups and values for lambs, yearlings and ewes were 0.009; 0.058 and 0.09, respectively (P<0.01). Statistical differences were observed in portal vein diameter, portal vein area and portal congestion index between the groups, presumably due to influence of weight and not to age.


1981 ◽  
Vol 96 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Kazumasa Chikamori ◽  
Fumie Suehiro ◽  
Toshiki Ogawa ◽  
Kei Sato ◽  
Hiroyoshi Mori ◽  
...  

Abstract. Synthetic LRH was infused into normal women and women with obesity and anorexia nervosa to determine the distribution volume (DV), metabolic clearance rate (MCR) and half disappearance time (t½) of plasma LRH. In normal women, the DV of LRH was 12.1 ± 0.9 (mean ± se) l, the MCR was 1478.9 ± 39.8 ml/min (28.5 ± 1.2 ml/min/kg body weight) and the initial t½ was 5.6 ± 0.4 min. In obese patients the DV (20.6 ± 1.5 l) was significantly higher than that in normal subjects (P < 0.005), but the MCR and t½ were not significantly different from those in normal subjects. In patients with anorexia nervosa the DV and MCR were 6.5 ± 1.1 l and 621.8 ± 110.5 ml/min (17.9 ± 2.4 ml/ min/kg body weight), respectively, which were both significantly lower than those in normal subjects (P < 0.02), while the t½ (7.3 ± 0.1 min) was longer than in normal subjects (P < 0.02). These data suggest that 1) the abnormal responses of some hormones to provocation tests observed in obese patients and patients with anorexia nervosa should be evaluated in consideration of changes in the DV and metabolic clearance of hormones in these conditions, and 2) in patients with anorexia nervosa changes in MCR and t½ may reflect low metabolism of LRH.


Author(s):  
Iyad Ali ◽  
Naser Shraim ◽  
Wafaa’ Atrash ◽  
Aisha Sirafi ◽  
Huda Abadi

Artificial Sweeteners (AS) are synthetic sugar substitutes that have sweetening potency hundreds of times more than the table sugar (sucrose). Artificial sweeteners are regarded as attractive alternatives to sugar as they add no calories to food intake. There are many hypotheses suggesting that AS may enhance appetite and cause weight gain. The aim of this study was to evaluate the effect of AS on food intake, fluid intake and body weight of mice. Acceptable daily intakes of AS solutions were administered orally to different set of mice for four weeks. The body weight, food consumption and fluid intake were measured. At the same time, the effect of Zingiber officinale extracts (natural appetite suppressor), Thymus vulgaris extracts (natural appetite inducer) and cyproheptadine (an appetite stimulant drug) on body weight of mice was evaluated. Artificial sweeteners consumption cause insignificant changes in body weight (p>0.05). However, the mean consumption of food and solutions varies significantly for some groups. The consumption of AS has no significant effect on body weight and may contribute to weight maintenance and energy balance as substitutes to high caloric sugar


Author(s):  
A. R. Monakhov ◽  
B. L. Mironkov ◽  
T. A. Dzhanbekov ◽  
K. O. Semash ◽  
Kh. M. Khizroev ◽  
...  

Introduction. Liver transplantation is a multi-component and complex type of operative treatment. Patients undergoing such a treatment sometimes are getting various complications. One of these complications is a portal hypertension associated with portal vein stenosis.Materials and methods. In 6 years after the left lateral section transplantation from living donor in a pediatric patient the signs of portal hypertension were observed. Stenosis of the portal vein was revealed. Due to this fact percutaneous transhepatic correction of portal vein stenosis was performed.Results. As a result of the correction of portal blood flow in the patient a positive trend was noted. According to the laboratory and instrumental methods of examination the graft had a normal function, portal blood flow was adequate. In order to control the stent patency Doppler ultrasound and MSCT of the abdominal cavity with intravenous bolus contrasting were performed. Due to these examinations the stent function was good, the rate of blood flow in the portal vein due to Doppler data has reached 80 cm/sec, and a decrease of the spleen size was noted.Conclusion. Diagnosis and timely detection of portal vein stenosis in patients after liver transplantation are very important for the preservation of graft function and for the prevention of portal hypertension. In order to do that, ultrasound Doppler fluorimetry examination needs to be performed to each patient after liver transplantation. In cases of violation of the blood flow in the portal vein CT angiography performance is needed. Percutaneous transhepatic stenting of portal vein is a minimally invasive and highly effective method of correction of portal hypertension. Antiplatelet therapy and platelet aggregation control are the prerequisites for successful stent function.


1998 ◽  
Vol 274 (3) ◽  
pp. H777-H785 ◽  
Author(s):  
Carl F. Rothe ◽  
Roberto Maass-Moreno

Changes in hepatic venous resistance were estimated in rabbits from the hepatic venular-inferior vena caval pressure gradient [servo-null micropipettes in 49 ± 15 (SD) μm vessels] and the total hepatic blood flow (ultrasound probe encircling the hepatic artery and the portal vein). Changes in liver volume, and thus vascular capacitance, were estimated from measures of the liver lobe thickness. Norepinephrine (NE), isoproterenol (Iso), adenosine (Ado), histamine (Hist), or acetylcholine (ACh) was infused into the portal vein at a constant rate for 5 min. NE, Hist, and Ado increased hepatic venular pressure, but only NE and Hist significantly increased hepatic venular resistance. NE reduced the liver thickness, but Hist and Ado caused engorgement. Hepatic blood flow was increased by NE and Ado and decreased by ACh. The influence of intraportal vein infusion of Iso on the liver vasculature, at doses similar to that of NE, was insignificant. We conclude that NE acted on all the hepatic microvasculature, increasing resistance and actively decreasing vascular volume. Hist passively induced engorgement by increasing outflow resistance, whereas the liver engorgement seen with Ado was passively related to the increased blood flow. ACh constricted the portal venules but did not change the liver volume.


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