Net uptakes of oestradiol-17β and progesterone across the portal-drained viscera and the liver of ewes

1994 ◽  
Vol 141 (2) ◽  
pp. 353-358 ◽  
Author(s):  
H C Freetly ◽  
C L Ferrell

Abstract The objective of this study was to determine whether circulating concentrations or prior exposure to oestradiol-17β (OE2) and progesterone affected their uptake by splanchnic tissues. Catheters were surgically placed in the portal vein, a branch of the hepatic vein, a mesenteric vein and the abdominal aorta of three multiparous ovariectomized Dorset ewes. Blood and plasma flow across the portal-drained viscera (PDV) and the liver, and net uptake of OE2 and O2 consumption in these same tissues were determined in ovariectomized ewes (control), during OE2 infusion into the jugular vein, 7 days after an OE2 implant had been given, and during OE2 infusion into the jugular vein 7 days after an OE2 implant. The above treatments were repeated for progesterone. Plasma flows across visceral organs were determined by marker dilution (para-aminohippuric acid), and OE2 and progesterone concentrations were determined by radioimmunoassay. During the infusion with OE2, OE2 arterial concentration (mean ± s.d.) was 346 ± 199 pg/ml, PDV net uptake was 9·7±5·6 μg OE2/h and hepatic net uptake was 15·5 ± 9·5 μg OE2/h. Hepatic uptake was 82% of the jugular OE2 infusion rate. Blood flow and oxygen consumption by hepatic tissue increased when ewes were exposed to an OE2 implant for 7 days. During the infusion with progesterone, progesterone arterial concentration (mean ± s.d.) was 8·8 ±3·4 ng/ml, PDV net uptake was 220 ± 118 μg progesterone/h and hepatic net uptake was 238 ± 52 μg progesterone/h. Hepatic net uptake was 23% of the progesterone jugular infusion rate. Journal of Endocrinology (1994) 141, 353–358

1997 ◽  
Vol 77 (2) ◽  
pp. 307-316 ◽  
Author(s):  
J. O. O. Miaron ◽  
R. J. Christopherson

Propranolol, a nonselective β-blocker and selective β-blockers (metoprolol a β1-blocker and ICI 118551 a β2-blocker) were used to investigate the β-adrenoceptor-mediated adrenaline-induced increase in whole-body and organ VO2 in five whether sheep. Transit time blood flow probes were chronically implanted on the portal vein and the external iliac artery and sampling catheters were placed in the mesenteric artery, iliac vein and portal vein. Oxygen consumption by the whole body was measured by open circuit calorimetry, and oxygen consumption by the portal-drained viscera and the hindquarter was determined from A-VO2 differences and organ blood flow. Absolute pre-infusion VO2 values for the whole body, portal-drained viscera and hindquarters were 236 ± 7.4, 61 ± 6.0 and 13 ± 3.1 mL min−1 respectively. The mean changes in VO2 in response to infusion were 74 vs. 11, 26, 10 and 12 mL min−1 (SE = 9.1) for whole body; 31 vs. −2, −15, 13 and −4 mL min−1 (SE = 7.3) for portal-drained viscera and 8 vs. −0.4, 2.1, 1.0 and −2.7 mL min−1; SE = 4.3) for hindquarters during adrenaline, control, propranolol, metoprolol and ICI 118551 treatments, respectively. Adrenaline increased VO2 (P < 0.05) in the whole body and portal-drained viscera, but not hindquarters relative to controls. All β-blockers suppressed (P < 0.05) the adrenaline-induced increase in VO2 except for the portal-drained viscera where metoprolol was less effective and the hindquarters where β-blockers had no effect. The blood flow pattern was similar to VO2 responses for the portal-drained viscera. The nonselective β1 and β2 blockers were effective in reducing the adrenaline-induced increases in blood flow from the portal-drained viscera and to the hindquarters, with more pronounced β-adrenoceptor-mediated haemodynamic effects. The results indicate that the β-adrenoceptor system modulates whole body VO2, clearly establishes that adrenaline induces an increased VO2 in portal-drained viscera which can be reversed by a β2 or nonselective β blocker and implicates β adrenoceptors as an influencing factor in the maintenance energy requirements of ruminants. Key words: Calorimetry, adrenaline, β blockers, blood flow, sheep


1989 ◽  
Vol 71 (Supplement) ◽  
pp. A162 ◽  
Author(s):  
Karen S. Bender ◽  
Billie L. Short ◽  
L. Kyle Walker ◽  
Christine A. Gleason ◽  
Richard J. Traystman

1991 ◽  
Vol 261 (1) ◽  
pp. E58-E65
Author(s):  
Z. Chap ◽  
Y. Okuda ◽  
J. Pena ◽  
J. B. Field

Oral glucose administration increases insulin secretion to a greater extent than peripheral glucose infusion (incretin effect). It also augments protal vein blood flow, hepatic uptake of glucose, and fractional hepatic extraction of insulin. The mechanisms for these various effects are not known but could involve both neurogenic stimuli and gut hormones. The present studies examined the effect of a non-nutrient drink, 1 g/kg body wt oral mannitol, on these parameters during an intravenous glucose infusion in conscious dogs. The dogs had chronically implanted Doppler flow probes on the portal vein and hepatic artery and catheters in the portal vein, hepatic vein, and femoral artery. After a 30-min control period, an infusion of atropine, propranolol, phentolamine, or propranolol and phentolamine was begun. Thirty minutes later, glucose (13 mg.kg-1.min-1) was then infused into a peripheral vein for 120 min with continuation of the atropine and adrenergic blockade. Water or mannitol (10% solution) was administered orally 50 min after the initiation of the glucose infusion. Mannitol, but not water, significantly enhanced the insulin response to intravenous glucose, as indicated by higher insulin concentrations in the portal vein as well as more rapid reduction of the plasma glucose. This incretin effect was significantly attenuated by infusion of propranolol but not by atropine or phentolamine. Mannitol did not increase portal vein blood flow or have any effect on the hepatic uptake of glucose or the fractional hepatic extraction of insulin. Thus absorption of nutrient is not necessary for the incretin effect but is for the increased portal vein blood flow and increased fractional extraction of insulin.(ABSTRACT TRUNCATED AT 250 WORDS)


1991 ◽  
Vol 81 (6) ◽  
pp. 751-758 ◽  
Author(s):  
Jean-Francois Liard

1. Arginine vasopressin reduces whole-body oxygen consumption in conscious dogs. To determine whether this decrease could result from limited oxygen delivery, studies were performed in two groups of chronically instrumented dogs. 2. In the first group (n = 7), vasopressin was infused at a rate of 18.5 pmol min−1 kg−1 while the animals were breathing 10% oxygen. Hypoxaemia alone (arterial partial pressure of oxygen 4.67 kPa) decreased whole-body oxygen delivery by 30%. The fall in whole-body oxygen consumption induced by vasopressin during hypoxaemia was not different from that measured under normoxic conditions, even though whole-body oxygen delivery was more reduced. 3. In a second group of seven dogs, hindquarter blood flow (electromagnetic flowmeter on lower abdominal aorta) and oxygen consumption (blood flow multiplied by arteriovenous oxygen difference) were measured as infusions of vasopressin were given either systemically or into the lower abdominal aorta. Systemic vasopressin infusions at 0.92, 4.6 and 18.5 pmol min−1 kg−1 reduced hindquarter blood flow, oxygen delivery and oxygen consumption, but the decreases in blood flow and oxygen delivery were dose-related whereas that in oxygen consumption was not. Intra-arterial infusions of vasopressin that increased venous concentrations as much as or more than systemic infusion of 0.92 pmol of vasopressin min−1 kg−1 had no effect on oxygen consumption, even though the higher intra-arterial rate reduced blood flow and oxygen delivery as much as the systemic infusion. Thus systemic but not locally administered vasopressin reduced hindquarter oxygen consumption. 4. Small to moderate mechanically induced reductions in hindquarter blood flow resulted in a smaller decrease in oxygen consumption than equivalent blood flow reductions induced by vasopressin. On the contrary, large mechanically induced flow reductions resulted in a larger decrease in oxygen consumption than those induced by vasopressin. 5. These results suggest that the decrease in hindquarter oxygen consumption induced by systemic vasopressin administration cannot be primarily a consequence of oxygen delivery limitation.


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.


Swiss Surgery ◽  
1999 ◽  
Vol 5 (3) ◽  
pp. 143-146 ◽  
Author(s):  
Launois ◽  
Maddern ◽  
Tay

The detailed knowledge of the segmental anatomy of the liver has led to a rapid evolution in resectional surgery based on the intrahepatic distribution of the portal trinity (the hepatic artery, hepatic duct and portal vein). The classical intrafascial or extrahepatic approach is to isolate the appropriate branch of the portal vein, hepatic artery and the hepatic duct, outside the liver substance. Another method, the extrafascial approach, is to dissect the whole sheath of the pedicle directly after division of a substantial amount of the hepatic tissue to reach the pedicle, which is surrounded by a sheath, derived from Glisson's capsule. This Glissonian sheath encloses the portal trinity. In the transfissural or intrahepatic approach, these sheaths can be approached either anteriorly (after division of the main, right or umbilical fissure) or posteriorly from behind the porta hepatis. We describe the technique for approaching the Glissonian sheath and hence the hepatic pedicle structures and their branches by the intrahepatic posterior approach that allows early delineation of the liver segment without the need for ancillary techniques. In addition, the indications for the use of this technique in the technical and oncologic settings are also discussed.


1965 ◽  
Vol 05 (03) ◽  
pp. 241-245 ◽  
Author(s):  
K.-F. Aronsen ◽  
B. Ericsson ◽  
A. Fajgelj ◽  
S.-E. Lindell

Summary 133Xe dissolved in saline was injected into the portal vein in man. Hepatic blood flow was calculated from the disappearance rate of 133Xe recorded with scintillation detectors placed over the liver. The results are discussed and related to simultaneous measurements of the pressure in the portal vein.


Diabetes ◽  
1979 ◽  
Vol 28 (10) ◽  
pp. 888-892 ◽  
Author(s):  
J. Jaspan ◽  
K. Polonsky ◽  
M. Lewis ◽  
A. R. Moossa
Keyword(s):  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tiantian Li ◽  
Shimeng Huang ◽  
Long Lei ◽  
Shiyu Tao ◽  
Yi Xiong ◽  
...  

Abstract Background Intrauterine growth restriction (IUGR) has negative impacts on the postnatal survival, growth and development of humans and animals, with not only on newborns but also adulthood. However, the characteristics for nutrient digestion and absorption in IUGR offspring are still largely unknown. Therefore, the normal birth weight (NBW) and IUGR growing pigs were used in this study to investigate their differences in nutrient utilization, with an expectition for further nutritional optimization of the IUGR offspring during their later life. Methods Twelve IUGR and 12 NBW growing pigs were fitted with catheters in their portal vein to measure blood flow rate as well as nutrients and metabolites in plasma. The digestibilities of nutrients in different intestinal segments, and bacterial fermentation in the large intestine were examined to reveal the characteristics of nutrients utilization in IUGR versus NBW pigs. Results The rate of portal venous blood flow did not differ beween IUGR and NBW pigs. Plasma concentrations of total cholesterol, triglycerides and glucose were much lower but those of urea were higher in the portal vein of IUGR pigs, compared with the NBW pigs. The ileal digestibility of dry matter, gross energy and starch were lower in IUGR pigs than in NBW pigs. IUGR increased hindgut microbial diversity and bacterial fermentation activity in the caecum. In vitro cross-fermentation of ileal digesta by caecal microbes of NBW and IUGR pigs showed that gas production was much higher for IUGR ileal digesta regardless of the source of caecal inocula. Conclusion IUGR impairs the nutrient digestion and absorption in small intestine, reduces caecal microbial diversity and promotes bacterial fermentation in the large intestine during the growing phase. These findings aid in our understanding of nutrient metabolism in IUGR pigs and provide the basis for future nutritional interventions.


1982 ◽  
Vol 242 (5) ◽  
pp. H805-H809 ◽  
Author(s):  
G. R. Heyndrickx ◽  
P. Muylaert ◽  
J. L. Pannier

alpha-Adrenergic control of the oxygen delivery to the myocardium during exercise was investigated in eight conscious dogs instrumented for chronic measurements of coronary blood flow, left ventricular (LV) pressure, aortic blood pressure, and heart rate and sampling of arterial and coronary sinus blood. After alpha-adrenergic receptor blockade a standard exercise load elicited a significantly greater increase in heart rate, rate of change of LV pressure (LV dP/dt), LV dP/dt/P, and coronary blood flow than was elicited in the unblocked state. In contrast to the response pattern during control exercise, there was no significant change in coronary sinus oxygen tension (PO2), myocardial arteriovenous oxygen difference, and myocardial oxygen delivery-to-oxygen consumption ratio. It is concluded that the normal relationship between myocardial oxygen supply and oxygen demand is modified during exercise after alpha-adrenergic blockade, whereby oxygen delivery is better matched to oxygen consumption. These results indicate that the increase in coronary blood flow and oxygen delivery to the myocardium during normal exercise is limited by alpha-adrenergic vasoconstriction.


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