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.

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.

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.

scholarly journals INFLUENCE OF HYPOXIA AND ADRENALINE ADMINISTRATION ON CORONARY BLOOD FLOW AND CARDIAC PERFORMANCE IN SEAWATER RAINBOW TROUT (ONCORHYNCHUS MYKISS)

1994 ◽  
Vol 193 (1) ◽  
pp. 209-232 ◽  
Author(s):  
A Gamperl ◽  
A Pinder ◽  
R Grant ◽  
R Boutilier
Keyword(s):  
Blood Flow ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Coronary Blood Flow ◽  
Cardiac Performance ◽  
Hypoxic Exposure ◽  
Coronary Perfusion ◽  
Adrenergic Stimulation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Cardiovascular Performance

To investigate the relationship between cardiac performance and coronary perfusion, cardiovascular variables (Q(dot), Vs, fh, Pda) and coronary blood flow (q·cor) were measured in rainbow trout (Oncorhynchus mykiss) (1.2­1.6 kg) before and after adrenergic stimulation (1.0 µg kg-1 adrenaline) under conditions of (1) normoxia, (2) hypoxia (approximate PwO2 12 kPa) and (3) 2.5 h after returning to normoxia. q·cor for resting fish under normoxic conditions was 0.14±0.02 ml min-1 kg-1 (approximately 0.85 % of Q(dot)). When exposed to hypoxia, although both resting Q(dot) and q·cor increased, q·cor increased to a greater degree (Q(dot) by 17 % and q·cor by 36 %). During hypoxia, maximum adrenaline-stimulated Q(dot) was comparable to that observed for normoxic fish. However, because Q(dot) was elevated in resting hypoxic fish, the capacity of hypoxic fish to increase Q(dot) above resting levels was 50 % lower than that measured in normoxic fish. Although maximum q·cor in adrenaline-injected hypoxic trout was greater than that measured in normoxic trout, post-injection increases in q·cor (above resting levels) were not different between the two groups. Two and a half hours after hypoxic exposure, resting Q(dot) was still elevated (11 %) above normoxic levels, and the ability to increase Q(dot) when adrenergically stimulated was not fully restored. These results suggest (1) that resting q·cor in salmonids is approximately 1 % of Q(dot), (2) that increases in q·cor may be important in maintaining cardiovascular performance during hypoxic conditions, (3) that interactions between alpha-adrenergic constriction and metabolically related vasodilation of the coronary vasculature are important in determining q·cor in fish, (4) that exposure of fish to moderate environmental hypoxia reduces the scope for adrenergically mediated increases in Q(dot), and (5) that periods of recovery in excess of several hours are required before cardiovascular performance returns to pre-hypoxic levels.

scholarly journals Dietary proteins improve hibernation and subsequent reproduction in the European hamster, Cricetus cricetus

2018 ◽  
Vol 315 (4) ◽  
pp. R848-R855
Author(s):  
Mathieu Weitten ◽  
Mathilde Louise Tissier ◽  
Jean-Patrice Robin ◽  
Caroline Habold
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Body Condition ◽  
Protein Composition ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
High Lipid ◽  
High Lipid Diet ◽  
Lipid Diet

The reproductive success of hibernators depends not only on food quality during reproduction but also on their body condition when emerging after hibernation, which, in turn, is highly dependent on the hibernation pattern. To date, no studies, to our knowledge, have fully investigated the role of macronutrients throughout the annual lifecycle of hibernators and the strong interdependency between its different phases. This study tested the effects of two diets with different lipid and protein composition on the prehibernation body condition, hibernation pattern, and reproduction of captive-reared European hamsters. Hamsters fed the high-lipid diet gained more body mass in the prehibernation period than those eating the high-protein diet, spent less time in torpor, and thus lost more body mass during hibernation. Despite similar body conditions in both groups at the start of reproduction, the group fed the high-protein diet had higher reproductive success, with more numerous and larger pups than in the high-lipid group. This study reveals that the macronutrient content of diets affects the different phases of the annual lifecycle in hamsters, each of which affects the next. Thus, a high-lipid diet induces less torpor use during hibernation because of a better prehibernation body condition and negatively impacts subsequent reproduction.

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