Distribution and characterisation of neuropeptide Y immunoreactivity in the brain and gastrointestinal tract of the rainbow trout, Oncorhynchus mykiss

Author(s):  
C.L. Barton ◽  
C. Shaw ◽  
D.W. Halton ◽  
C.F. Johnston ◽  
K.D. Buchanan
2011 ◽  
Vol 56 (No. 2) ◽  
pp. 61-69 ◽  
Author(s):  
Z.-H. Li ◽  
V. Zlabek ◽  
J. Velíšek ◽  
R. Grabic ◽  
J. Machová ◽  
...  

In this study, the toxic effects of PCZ, a triazole fungicide present in aquatic environment, were studied in rainbow trout, Oncorhynchus mykiss, by an acute toxicity test. Compared to the control group, fish exposed to PCZ (96-h-LC50, 5.04 mg/l) showed significantly higher (P < 0.05) plasma NH3 and GLU concentration and the activities of plasma enzymes including CK, ALT, AST, LDH, but the TP content was not significantly different (P > 0.05). The oxidative stress indices (levels of LPO and CP) of brain and muscle in the experimental group were higher compared to the control group, especially for a significant change (P < 0.05) in the brain. SOD, CAT, GPx and GR activity in the brain of experimental groups was significantly lower (P < 0.05), however, an opposite tendency was found out in muscle. In addition, there are significant correlations between TBARS and CAT, TBARS and GPx, CP, and CAT, GR, and GPx in the fish brain. Thus, PCZ exposure changed the oxidative stress indices and plasma characteristics, and these changes may be used as potential bioindicators of the exposure and effect of PCZ in the controlled experiment. The use in monitoring of PCZ exposure under natural field conditions is possible, but it needs further investigations.


2008 ◽  
Vol 294 (5) ◽  
pp. R1648-R1656 ◽  
Author(s):  
Henrik Seth ◽  
Erik Sandblom ◽  
Susanne Holmgren ◽  
Michael Axelsson

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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