Increased expression in calcitonin-like receptor induced by aldosterone in cerebral arteries from spontaneously hypertensive rats does not correlate with functional role of CGRP receptor.
OBJECTIVE
To analyze the effect of aldosterone on the expression of calcitonin gene-related peptide (CGRP) receptor components, calcitonin-like receptor (CL receptor) and receptor activity modifying protein 1 (RAMP1), as well as the effect of this mineralocorticoid on CGRP-mediated vasodilation in middle cerebral arteries from Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR).


RESULTS
CGRP 0.1 nM-0.1 microM induced a concentration-dependent relaxation that was nitric oxide independent and higher in SHR middle cerebral arteries. CL receptor and RAMP1 expression were similar in both strains. The relaxation to CGRP was not modified by aldosterone 1 microM in either strain, although aldosterone 1 microM increased expression of CL receptor without modifying RAMP1 in segments from SHR rats.


CONCLUSIONS
CGRP elicits greater vasodilation in middle cerebral arteries from SHR than WKY rats, that is nitric oxide independent, and by mechanism independent of CGRP receptor components expression. Although aldosterone increases the expression of CL receptor in SHR, it does not alter vasodilation to CGRP, since RAMP1 expression is not increased. These results indicate that the increase in CL receptor, without an increase in RAMP1, does not correlate with changes in functional role of the CGRP receptor.
Márquez-Rodas
Iván
I
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma de Madrid, Spain.
Xavier
Fabiano E
FE
Arroyo-Villa
Irene
I
Longo
Federico
F
Aras-Lopez
Rosa
R
Blanco-Rivero
Javier
J
Ferrer
Mercedes
M
Balfagón
Gloria
G
D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D058286:Calcitonin Receptor-Like Protein; D002536:Cerebral Arteries / Q000187:drug effects* / Q000378:metabolism; D006973:Hypertension; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D058261:Receptor Activity-Modifying Proteins; D018003:Receptors, Calcitonin / Q000187:drug effects / Q000378:metabolism*; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000502:physiology*; D015854:Up-Regulation
D058286:Calcitonin Receptor-Like Protein; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D058261:Receptor Activity-Modifying Proteins; D018003:Receptors, Calcitonin; D018015:Receptors, Calcitonin Gene-Related Peptide; D000450:Aldosterone