Effect of postprandrial hypoxia challenge on oxygen consumption and gut blood flow in rainbow trout (Oncorhynchus mykiss)

2007 ◽  
Vol 146 (4) ◽  
pp. S177
Author(s):  
E. Eliason
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Rainbow Trout Oncorhynchus Mykiss

Cholecystokinin as a regulator of cardiac function and postprandial gastrointestinal blood flow in rainbow trout (Oncorhynchus mykiss)

2010 ◽  
Vol 298 (5) ◽  
pp. R1240-R1248 ◽  
Author(s):  
Henrik Seth ◽  
Albin Gräns ◽  
Michael Axelsson
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Direct Effect ◽  
Flow Profile ◽  
Subsequent Increase ◽  
Physiological Concentration ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Gastrointestinal Blood Flow

We have studied the potential role of CCK as a regulator/modulator of the postprandial increase in gastrointestinal blood flow. Rainbow trout ( Oncorhynchus mykiss ) were instrumented with pulsed Doppler flow probes to measure the effects of CCK on cardiac output and gastrointestinal blood flow. Furthermore, vascular preparations were used to study the direct effects of CCK on the vessels. In addition, we used in situ perfused hearts to further study the effects of CCK on the cardiovascular system. When the sulfated form of CCK-8 was injected at a physiological concentration (0.19 pmol/kg) in vivo, there was a significant increase in the gastrointestinal blood flow (18 ± 4%). This increase in gastrointestinal blood flow was followed by a subsequent increase in cardiac output (30 ± 6%). When the dose was increased to 0.76 pmol/kg, there was only a 14 ± 6% increase in gastrointestinal blood flow; possibly due to a dose-dependent increase in the gill vascular resistance as previously reported or a direct effect on the heart. Nevertheless, CCK did not affect the isolated vessel preparations, and thus, it seems unlikely that CCK has a direct effect on the blood vessels of the second or third order. CCK did, however, have profound effects on the dynamics of the heart, and without a change in cardiac output, there was a significant increase in the amplitude (59 ± 4%) and rate (dQ/d t: 55 ± 4%; -dQ/d t: 208 ± 49%) of the phasic flow profile. If and how this might be coupled to a postprandial gastrointestinal hyperemia remains to be determined. We conclude that CCK has the potential as a regulator of the postprandial gastrointestinal blood flow in fish and most likely has its effect by inducing a gastrointestinal hyperemia. The mechanism by which CCK acts is at present unknown.

Influence of low temperature acclimation on fate of metabolic fuels in rainbow trout (Oncorhynchus mykiss) hearts

1993 ◽  
Vol 71 (11) ◽  
pp. 2167-2173 ◽  
Author(s):  
John R. Bailey ◽  
William R. Driedzic
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Temperature Acclimation ◽  
Experimental Conditions ◽  
Intracellular Lipids ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Significant Difference ◽  
Precipitate Protein ◽  
Fuel Source

Rainbow trout (Oncorhynchus mykiss) were acclimated to 5 and 20 °C. Oxygen consumption of isolated perfused hearts was measured at 5 or 15 °C with either glucose or palmitate as the exogenous fuel source. With glucose as the fuel there was no significant difference in oxygen consumption of hearts from either acclimation group at either temperature. With palmitate as the fuel source, hearts from fish acclimated to and tested at 5 °C had significantly higher oxygen consumption than hearts from fish acclimated to 20 °C and tested at either 5 or 15 °C. Hearts from fish both acclimated to and tested at 5 °C had a higher oxygen consumption with palmitate than when glucose was supplied. This reflects the preference for fatty acid fuels found in cold acclimated muscle tissue, and consequently the amount of oxygen required to utilize fats. Under all experimental conditions, 14CO2 production from either (6-14C)glucose or (1-14C)palmitate could account for less than 0.5% of oxygen consumption. Tissue chemical analysis showed that most of the label from (6-14C)glucose appeared in acid-soluble (glycolytic intermediates, citric acid cycle intermediates, amino acids, etc.) and lipid fractions while most of the label from (1-14C)palmitate appeared in lipid- or acid-soluble or acid precipitate (protein material) fractions. This indicates considerable dilution of exogenous fuels in endogenous pools, which could account for the discrepancy in measured O2 consumption and 14CO2 production. Glucose catabolism was little affected by either acute or chronic changes in temperature other than an increase in glucose incorporation into the glycogen pool. Hearts from fish both acclimated to and tested at 5 °C showed an increased handling of exogenous fatty acids as reflected by elevated rates of catabolism and incorporation into intracellular lipids.

Nutrient-induced gastrointestinal hyperemia and specific dynamic action in rainbow trout (Oncorhynchus mykiss)—importance of proteins and lipids

2009 ◽  
Vol 296 (2) ◽  
pp. R345-R352 ◽  
Author(s):  
Henrik Seth ◽  
Erik Sandblom ◽  
Michael Axelsson
Keyword(s):  
Blood Flow ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
High Protein Diet ◽  
Specific Dynamic Action ◽  
Protein Diet ◽  
Balanced Diet ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
High Lipid ◽  
High Lipid Diet

Mechanical gastric distension induces a dorsal aortic pressor response in rainbow trout ( Oncorhynchus mykiss) with no change in gastrointestinal blood flow. To elucidate what role chemical stimuli from the digested food has on the postprandial cardiovascular response, a new method was developed to investigate the contribution of individual nutrient components. Three predigested experimental diets were injected directly into the proximal intestine of rainbow trout and cardiac output (CO), gut blood flow (Qcma), heart rate (HR), and stroke volume (SV) were recorded. Specific dynamic action (SDA) was estimated by measuring oxygen consumption. When a balanced diet (50% protein, 25% fat, 15% carbohydrate) was injected, Qcma and CO increased within 1 h by 45 and 27%, respectively. The response to a high-protein diet (70% protein, 5% fat, 15% carbohydrate) was quantitatively similar but delayed, with a maximal blood flow response after 2 h. With a high-lipid diet (60% fat, 15% protein, 15% carbohydrate), the peak increase in Qcma by 22% occurred after 30 min and thereafter declined rapidly. The SDA response (19%) to the balanced diet was temporally matched with the hyperemia. With a high-protein diet, the response is delayed and enlarged (34%) compared with the balanced diet. The high-lipid diet gave no significant SDA response. We conclude that the chemical composition of the food influences the postprandial hyperemia and the SDA, such that the components appear to work in a synergistic fashion. The present results also demonstrate that both redistribution of blood flow and an overall increase in CO contribute to the postprandial increase in gut blood flow in this species.

Metabolic effects of the expression of a phosphoglucomutase locus in the liver of rainbow trout

1990 ◽  
Vol 68 (7) ◽  
pp. 1499-1504
Author(s):  
Moira M. Ferguson ◽  
Roy G. Danzmann ◽  
Fred W. Allendorf ◽  
Kathy L. Knudsen
Keyword(s):  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
White Muscle ◽  
Metabolic Effects ◽  
Parallel Analysis ◽  
Separate Experiment ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Consumption Rates ◽  
Sib Families

We examined the lengths, weights, condition factors, and hepatosomatic indices of juvenile rainbow trout (Oncorhynchus mykiss) from four full-sib families, each segregating at the temporal regulatory locus Pgm1-t, and the concentrations of RNA, DNA, and protein in their livers and white muscle. In three families, fish with phosphoglucomutase-1 (PGM1) activity in liver (Pgm1-t(b) fish) are significantly longer than their full-sibs lacking activity for liver PGM1 (Pgm1-t(a) fish). Hepatosomatic indices tend to be higher in the Pgm1-t(b) fish than in their Pgm1-t(a) siblings. RNA/DNA ratios in the liver of Pgm1-t(b) fish are significantly higher than those of Pgm1-t(a) fish in two families and marginal in a third. However, no significant differences were detected in a parallel analysis of nucleic acids and protein in white muscle, where PGM1 is expressed in all fish. In a separate experiment, Pgm1-t(b) fish were significantly heavier in all five families, had significantly higher condition factors in two families, and had marginally lower standardized oxygen consumption rates in three families.

Effects of gastric distension on the cardiovascular system in rainbow trout (Oncorhynchus mykiss)

2008 ◽  
Vol 294 (5) ◽  
pp. R1648-R1656 ◽  
Author(s):  
Henrik Seth ◽  
Erik Sandblom ◽  
Susanne Holmgren ◽  
Michael Axelsson
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Rainbow Trout ◽  
Gastrointestinal Tract ◽  
Arterial Pressure ◽  
Oncorhynchus Mykiss ◽  
Vascular Resistance ◽  
Stomach Wall ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Chemical Stimuli

When animals feed, blood flow to the gastrointestinal tract increases to ensure an adequate oxygen supply to the gastrointestinal tissue and an effective absorption of nutrients. In mammals, this increase depends on the chemical properties of the food, as well as, to some extent, on the mechanical distension of the stomach wall. By using an inflatable nitrile balloon positioned in the stomach, we investigated the cardiovascular responses to mechanical stretch of the stomach wall in rainbow trout ( Oncorhynchus mykiss). Distension with a volume equivalent to a meal of 2% of the body mass increased dorsal aortic blood pressure by up to 29%, and central venous blood pressure increased transiently nearly fivefold. The increase in arterial pressure was mediated by an increased vascular resistance of both the systemic and the intestinal circulation. Cardiac output, heart rate, and stroke volume (SV) did not change, and only transient changes in gut blood flow were observed. The increase in arterial pressure was abolished by the α-adrenergic antagonist prazosin, indicating an active adrenergic vasoconstriction, whereas the venous pressor response could be the consequence of a passive increase in intraperitoneal pressure. Our results show that mechanical distension of the stomach causes an instantaneous increase in general vascular resistance, which may facilitate a redistribution of blood to the gastrointestinal tract when chemical stimuli from a meal induce vasodilation in the gut circulation. The normal postprandial increase in gut blood flow in teleosts is, therefore, most likely partly dependent on mechanical stimuli, as well as on chemical stimuli.

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