Related Experiment Videos
Angiotensin receptor(s) in fowl
1INSERM U36 and Collège de France, 3 rue d'Ulm, 75005, Paris, France. hkempf@infobiogen.fr
Summary
The avian angiotensin II (Ang II) receptor is molecularly similar to mammalian AT(1) receptors but exhibits unique antagonist specificity. Its expression pattern suggests a distinct role, reinforcing evidence for a novel avian Ang II receptor type.
Area of Science:
- Pharmacology
- Molecular Biology
- Endocrinology
Background:
- Angiotensin II (Ang II) receptors are crucial in regulating cardiovascular function.
- Mammalian Ang II receptors are classified into AT(1) and AT(2) types.
- The avian Ang II receptor's classification remains unclear.
Purpose of the Study:
- To characterize the avian Ang II receptor pharmacologically and functionally.
- To determine the expression pattern of the avian Ang II receptor.
- To compare the avian Ang II receptor with mammalian AT(1) and AT(2) receptors.
Main Methods:
- Cloning of the avian Ang II receptor.
- Pharmacological characterization in transfected cells.
- Analysis of avian Ang II receptor mRNA expression in adult and embryonic tissues.
Main Results:
- The avian Ang II receptor is molecularly close to mammalian AT(1) receptors.
- It couples to phospholipase C but shows different antagonist specificity compared to mammalian types.
- mRNA is expressed in adult target organs and endothelial cells, not vascular smooth muscle.
- Embryonic expression overlaps with AT(2) receptor patterns.
Conclusions:
- The avian Ang II receptor is atypical and cannot be readily classified as AT(1) or AT(2).
- It may mediate Ang II-induced vasorelaxation in endothelial cells.
- These findings support the existence of a distinct avian Ang II receptor class.