1. Central and Peripheral Cardiovascular Effects of Angiotensin III in Trout
- Author
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Frédéric Lancien, J. C. Le Mevel, and Nagi Mimassi
- Subjects
Bradycardia ,medicine.medical_specialty ,biology ,Trout ,Chemistry ,General Neuroscience ,Angiotensin III ,Baroreflex ,biology.organism_classification ,Cardiovascular System ,General Biochemistry, Genetics and Molecular Biology ,Blood pressure ,Endocrinology ,History and Philosophy of Science ,Internal medicine ,Renin–angiotensin system ,Heart rate ,cardiovascular system ,medicine ,Animals ,Rainbow trout ,medicine.symptom ,hormones, hormone substitutes, and hormone antagonists - Abstract
The present study was undertaken to determine the central and peripheral actions of trout angiotensin III (ANG III) on heart rate (HR) and mean dorsal aortic blood pressure (P(DA)) in the unanaesthetized rainbow trout. Intracerebroventricular injection of ANG III (5-100 pmol) produced a significant and dose-dependent increase in HR without significant change in P(DA). In contrast, when injected peripherally ANG III (5-50 pmol) evoked a significant and dose-dependent increase in P(DA). The hypertensive responses were accompanied by a bradycardia that reached significance only for the highest dose of ANG III tested. In conclusion, our results have shown that ANG III has potent and contrasting cardiovascular actions depending on whether its site of action is the brain or the peripheral circulation. Endogenous ANG III may have important physiological functions in teleost fishes.
- Published
- 2009
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