Postprandial hemodynamics and oxygenation in developing piglet intestine

1991 ◽  
Vol 260 (6) ◽  
pp. G951-G957 ◽  
Author(s):  
K. D. Crissinger ◽  
D. L. Burney
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Venous Pressure ◽  
Age Groups ◽  
Mucosal Blood Flow ◽  
Mucosal Injury ◽  
Oxygen Extraction ◽  
Cow Milk ◽  
Similar Extent ◽  
Age Related

Age-related differences in the intestinal hemodynamic and oxygenation responses to feeding were studied in 1-day- (never-nursed and nursed-fasted), 3-day-, 2-wk-, and 1-mo-old piglets. A distal branch of the superior mesenteric vein draining an isolated loop of jejunoileum was used to measure intestinal blood flow, arteriovenous oxygen content difference, venous pressure, and capillary pressure. Calculations of oxygen uptake and vascular resistance were performed from the measured variables. Radioactive microspheres were used to measure fractionated flow. After luminal instillation of a cow milk-based formula, postprandial oxygen uptake increased to a similar extent in all age groups. In never-nursed newborns the increase was achieved by a dramatic rise in oxygen extraction with no change in total flow, while all other groups demonstrated a combined increase in blood flow and oxygen extraction. Mucosal blood flow increased to a similar extent in all age groups, but in never-nursed newborns it was at the expense of muscularis-serosa flow. Thus, because oxygen extraction and mucosal blood flow appear to be near maximal during feeding alone, newborn intestine may be at risk for tissue hypoxia and subsequent mucosal injury in the presence of a superimposed cardiovascular stress.

Influence of luminal nutrient composition on hemodynamics and oxygenation in developing intestine

1992 ◽  
Vol 263 (2) ◽  
pp. G254-G260 ◽  
Author(s):  
K. D. Crissinger ◽  
D. L. Burney
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Vascular Resistance ◽  
Corn Oil ◽  
Age Groups ◽  
Older Age ◽  
Intestinal Blood Flow ◽  
Oxygen Extraction ◽  
Age Related

Age-related differences in the intestinal hemodynamic and oxygenation responses to carbohydrate, protein, and lipid were studied in 1-day-, 3-day-, 2-wk-, and 1-mo-old piglets. A branch of the mesenteric vein draining an isolated loop of jejunoileum was used to measure intestinal blood flow, arteriovenous oxygen content difference, and venous and capillary pressure and to calculate oxygen uptake and vascular resistance. Fractionated intestinal flow was measured with radiolabeled microspheres. Measurements were made before and after luminal placement of either 5% glucose, 2.3% casec, or 5% corn oil. In 1-day-old animals, unlike all older age groups, total intestinal blood flow and vascular resistance were unchanged by any nutrient. Fractionated flow to the mucosa/submucosa levels did, however, increase in the intestine of 1-day-old piglets to a similar extent as that in older age groups. Placement of lipid or protein into the lumen led to increased oxygen uptake in all age groups, whereas carbohydrate absorption resulted in no increase in intestinal oxygen consumption in 1- and 3-day-old animals. In 1-day-olds, the increased oxygen consumption was achieved by enhanced oxygen extraction with no change in total blood flow, whereas all other groups demonstrated increases in blood flow and/or oxygen extraction. Compared with a mixed meal, oxygen consumption was not significantly greater for an individual nutrient component.

Autoregulation of gastric blood flow and oxygen uptake

1981 ◽  
Vol 241 (2) ◽  
pp. G143-G149
Author(s):  
L. Holm-Rutili ◽  
M. A. Perry ◽  
D. N. Granger
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Arterial Pressure ◽  
Vascular Resistance ◽  
Perfusion Pressure ◽  
Venous Pressure ◽  
Oxygen Demand ◽  
Gastric Blood Flow ◽  
Oxygen Extraction ◽  
Sympathetic Denervation

The purpose of this study was to determine whether the ability of the stomach to autoregulate blood flow and oxygen uptake is altered by sympathetic denervation. Blood flow, oxygen extraction, local arterial pressure, and venous pressure were continuously monitored in sympathetically innervated and denervated autoperfused dog stomach preparations. As perfusion pressure was reduced in increments from 120 to 20 mmHg in innervated preparations, blood flow and oxygen uptake decreased while oxygen extraction and vascular resistance increased. Reductions in perfusion pressure in denervated preparations resulted in a decrease in blood flow, oxygen uptake, and vascular resistance, whereas oxygen extraction increased. The ability of the stomach to regulate blood flow and oxygen uptake was significantly improved after denervation, i.e., vascular resistance decreased and oxygen uptake remained relatively constant when arterial pressure was reduced. Oxygen uptake in denervated stomachs was generally higher than that in innervated stomachs. Autoregulation of gastric blood flow therefore appears to be improved by denervation. The better autoregulation observed after denervation may result either from a reduction in sympathetic tone and/or the increase in gastric oxygen demand.

scholarly journals Role of capsaicin sensitive nerves in epidermal growth factor effects on gastric mucosal injury and blood flow

Gut ◽  
1998 ◽  
Vol 42 (3) ◽  
pp. 344-350 ◽  
Author(s):  
J Y Kang ◽  
C H Teng ◽  
F C Chen ◽  
A Wee
Keyword(s):  
Blood Flow ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mucosal Blood Flow ◽  
Gastric Mucosal Blood Flow ◽  
Mucosal Injury ◽  
Gastric Mucosal Injury ◽  
Gastric Mucosal Damage ◽  
Arterial Infusion ◽  
Epidermal Growth

Background—Epidermal growth factor (EGF) and capsaicin protect against experimental gastric mucosal injury. Capsaicin exerts its gastroprotective effect by stimulating afferent neurones leading to release of calcitonin gene related peptide (CGRP) which causes gastric hyperaemia. EGF also causes gastric hyperaemia but whether it acts via capsaicin sensitive neurones is unknown.Aims—To assess the influence of: (1) capsaicin desensitisation on EGF effects on gastric mucosal injury and gastric mucosal blood flow; and (2) close arterial infusion of hCGRP8–37, a CGRP antagonist, on EGF effects on gastric mucosal blood flow.Methods—The absolute ethanol induced gastric mucosal injury model in the rat was used. Gastric mucosal damage was assessed by planimetry and light microscopy. Gastric mucosal blood flow was measured by laser Doppler flowmetry in a gastric chamber preparation.Results—Capsaicin desensitisation abolished the gastroprotective and gastric hyperaemic effects of EGF. Close arterial infusion of hCGRP8–37 antagonised the hyperaemic effect of both capsaicin and EGF.Conclusion—Results show that EGF may exert its gastroprotective and gastric hyperaemic effects via capsaicin sensitive afferent neurones.

Age-Related Differences in Perceived Exertion While Walking and Running Near the Preferred Transition Speed

2020 ◽  
Vol 32 (4) ◽  
pp. 227-232
Author(s):  
Stacey M. Kung ◽  
Philip W. Fink ◽  
Stephen J. Legg ◽  
Ajmol Ali ◽  
Sarah P. Shultz
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Relative Intensity ◽  
Perceived Exertion ◽  
Age Groups ◽  
Peak Oxygen Uptake ◽  
Transition Speed ◽  
Age Related ◽  
All Speeds ◽  
Preferred Transition Speed

Purpose: To investigate whether youth and adults can perceive differences in exertion between walking and running at speeds near the preferred transition speed (PTS) and if there are age-related differences in these perceptions. Methods: A total of 49 youth (10–12 y, n = 21; 13–14 y, n = 10; 15–17 y, n = 18) and 13 adults (19–29 y) completed a walk-to-run transition protocol to determine PTS and peak oxygen uptake. The participants walked and ran on a treadmill at 5 speeds (PTS–0.28 m·s−1, PTS–0.14 m·s−1, PTS, PTS+0.14 m·s−1, PTS+0.28 m·s−1) and rated perceived exertion using the OMNI Perceived Exertion (OMNI-RPE) scale. Oxygen consumption was measured during the walk-to-run transition protocol to obtain the relative intensity (percentage of peak oxygen uptake) at PTS. OMNI-RPE scores at all speeds and percentage of peak oxygen uptake at PTS were compared between age groups. Results: The 10- to 12-year-olds transitioned at a higher percentage of peak oxygen uptake than adults (64.54 [10.18] vs 52.22 [11.40], respectively; P = .035). The 10- to 14-year-olds generally reported higher OMNI-RPE scores than the 15- to 17-year-olds and adults (P < .050). In addition, the 10- to 14-year-olds failed to distinguish differences in OMNI-RPE between walking and running at PTS and PTS+0.14 m·s−1. Conclusions: Children aged 10–14 years are less able to distinguish whether walking or running requires less effort at speeds near the PTS compared with adults. The inability to judge which gait mode is less demanding could hinder the ability to minimize locomotive demands.

Autoregulation in the developing postnatal intestinal circulation

1988 ◽  
Vol 254 (2) ◽  
pp. G189-G193 ◽  
Author(s):  
P. T. Nowicki ◽  
C. E. Miller
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Partial Pressure ◽  
Perfusion Pressure ◽  
Venous Pressure ◽  
Arterial Perfusion ◽  
Perfusion Apparatus ◽  
Intrinsic Regulation ◽  
Intestinal Circulation

The relationships among perfusion pressure, blood flow, and oxygen uptake were determined in in vitro ileal loops from 3- and 35-day-old swine. Arterial perfusion of the ileal loops was achieved using a reservoir perfusion apparatus that allowed direct manipulation of perfusion pressure. The hematocrit, partial pressure of oxygen, and partial pressure of carbon dioxide of the blood used to perfuse the gut loops were standardized. During steady-state perfusion at an arterial pressure of 100 mmHg and venous pressure of 0 mmHg, ileal loops from 3-day-old swine demonstrated a higher blood flow (55 vs. 27 ml.min-1.100 g-1, 3 vs. 35 day old) and lower arteriovenous oxygen content difference (3.5 vs. 6.6 ml O2/dl). Oxygen uptake was not statistically different between groups (1.99 vs. 1.76 ml O2.min-1.100 g-1). During perfusion pressure reduction from 150 to 25 mmHg (in successive decrements of 25 mmHg), pressure-flow autoregulation was present in ileal loops from 35-day-old swine but not in ileal loops from 3-day-old swine. Similarly, tissue oxygen uptake was more effectively maintained in ileal loops from older swine during perfusion pressure reductions. We speculate that the efficacy of intrinsic regulation of intestinal hemodynamics and oxygenation is dependent, in part, on postnatal age.

Mucosal Blood Flow Stasis and Hypoxemia as the Pathogenesis of Acute Gastric Mucosal Injury

1990 ◽  
Vol 12 ◽  
pp. S85-S91 ◽  
Author(s):  
Shingo Tsuji ◽  
Sunao Kawano ◽  
Nobuhiro Sato ◽  
Takenobu Kamada
Keyword(s):  
Blood Flow ◽  
Mucosal Blood Flow ◽  
Mucosal Injury ◽  
Gastric Mucosal Injury ◽  
Flow Stasis

Differences between the effects of noradrenaline and the β-adrenoceptor agonist BRL 28410 in brown adipose tissue and hind limb of the anaesthetized rat

1986 ◽  
Vol 64 (8) ◽  
pp. 1111-1114 ◽  
Author(s):  
Peter L. Thurlby ◽  
Rodney D. M. Ellis
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Oxygen Uptake ◽  
Brown Adipose Tissue ◽  
Oxygen Delivery ◽  
Hind Limb ◽  
Oxygen Extraction ◽  
Whole Body ◽  
Adrenoceptor Agonist ◽  
Brown Adipose

In mature (450–600 g) 21 °C-acclimated male rats, anaesthetized with urethane, blood flow (measured by the radioactive microsphere technique) to brown adipose tissue (BAT) was determined during the infusion of the β-adrenoceptor agonist BRL 28410 or noradrenaline bitartrate at doses chosen to give similar increases in whole body oxygen uptake. Blood flow to BAT during BRL 28410 infusion was only about one third of that found during noradrenaline infusion although increases in whole body thermogenesis were similar (55 and 77% for BRL 28410 and noradrenaline, respectively). This suggests that BAT may be less involved in the thermogenic response to BRL 28410 than to noradrenaline. In a separate experiment using slightly smaller rats (350–500 g) hind limb oxygen uptake was measured in situ using a venous bypass preparation. BRL 28410, at a dose having a maximum effect on whole body thermogenesis (53% increase), had no effect on oxygen delivery to the hind limb but significantly increased oxygen extraction by 33% (p < 0.001). In contrast, noradrenaline, also at a dose that maximally increased whole body thermogenesis, led to a 35% decrease in oxygen delivery to the hind limb and no change in oxygen extraction. For the thermogenic β-agonist BRL 28410 the hind limb, and presumably muscular tissue in general, may be contributing to thermogenesis.

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