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Exercise training attenuates anaphylactic venoconstriction in rat perfused liver, but does not affect anaphylactic hypotension in conscious rats.
- Source :
-
Clinical and experimental pharmacology & physiology [Clin Exp Pharmacol Physiol] 2010 Sep; Vol. 37 (9), pp. 889-93. Date of Electronic Publication: 2010 Apr 26. - Publication Year :
- 2010
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Abstract
- 1. Exercise training attenuates circulatory shock due to haemorrhage, endotoxin or heatstroke. However, it remains unknown whether exercise training attenuates anaphylactic shock. Hepatic venoconstriction is involved in rat anaphylactic hypotension. In the present study, we determined the effects of exercise training on both anaphylaxis-induced segmental venoconstriction in rat perfused livers and systemic anaphylaxis in conscious rats. The role of nitric oxide (NO) in the effect of exercise on the venoconstriction of perfused livers was also examined. 2. Rats were subjected to running training on a motorized treadmill for 4 weeks. Two weeks prior to the anaphylaxis experiment, Sprague-Dawley rats were actively sensitized with the antigen ovalbumin. In isolated livers perfused portally with blood, the portal venous pressure (P(pv)) and sinusoidal pressure were measured to determine the pre- and post-sinusoidal resistances (R(pre) and R(post), respectively). In conscious rats, systemic arterial pressure (SAP) and P(pv) were determined. 3. In the perfused livers of sedentary rats, antigen administration led to a predominant presinusoidal constriction, as evidenced by 4.6- and 1.7-fold increases in R(pre) and R(post), respectively. The anaphylaxis-induced increase in R(pre) was significantly attenuated by 24% by exercise training. Inhibition of NO synthase with N(G)-nitro-L-arginine methyl ester (100 micromol/L) 10 min prior to the injection of antigen enhanced anaphylactic venoconstriction, but did not alter the effect of exercise training on the increase in R(pre). In contrast, exercise training did not attenuate either anaphylactic hypotension or portal hypertension in conscious rats. 4. In conclusion, exercise training attenuates the anaphylaxis-induced presinusoidal constriction in rat isolated perfused livers, independent of NO production. However, this action is not evident in conscious rats and exercise training does not affect anaphylactic hypotension in conscious rats.
- Subjects :
- Anaphylaxis immunology
Animals
Enzyme Inhibitors administration & dosage
Enzyme Inhibitors pharmacology
Liver physiopathology
Liver Circulation drug effects
Liver Circulation physiology
Male
NG-Nitroarginine Methyl Ester administration & dosage
NG-Nitroarginine Methyl Ester pharmacology
Nitric Oxide metabolism
Ovalbumin administration & dosage
Ovalbumin immunology
Ovalbumin pharmacology
Perfusion
Portal Pressure drug effects
Rats
Rats, Sprague-Dawley
Vascular Resistance drug effects
Vascular Resistance physiology
Anaphylaxis physiopathology
Hypotension physiopathology
Liver blood supply
Physical Conditioning, Animal
Vasoconstriction
Subjects
Details
- Language :
- English
- ISSN :
- 1440-1681
- Volume :
- 37
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Clinical and experimental pharmacology & physiology
- Publication Type :
- Academic Journal
- Accession number :
- 20456421
- Full Text :
- https://doi.org/10.1111/j.1440-1681.2010.05401.x