Premium
Collar‐induced elevation of mRNA and functional activity of 5‐HT 1B receptor in the rabbit carotid artery
Author(s) -
Geerts Inge S,
De Meyer Guido R Y,
Bult Hidde
Publication year - 2000
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0703732
Subject(s) - receptor , ketanserin , messenger rna , medicine , 5 ht receptor , endocrinology , serotonin , carotid body , biology , spiperone , anatomy , carotid arteries , chemistry , biochemistry , gene
Hypersensitivity to serotonin (5‐HT) develops in rabbit collared carotid arteries. Previous data demonstrated the involvement of 5‐HT 1 ‐like receptors which are not active in normal carotid arteries. This study investigated the interaction in the rabbit carotid artery between 5‐HT and a moderate tone as this can uncover functional 5‐HT 1 ‐like receptors. Furthermore, the expression of messenger RNA (mRNA) and protein of 5‐HT 1B , 5‐HT 1D and 5‐HT 2A receptors was addressed. Silicone collars were placed around the carotid arteries of male New Zealand White rabbits for 1 week. Rings from inside (=collar) and outside (=sham) the collar were either mounted in isolated organ baths for isometric force measurements or frozen in liquid nitrogen to isolate total RNA or proteins which were subsequently analysed by respectively reverse transcriptase‐polymerase chain reaction and Western blot analysis. In sham and collared rings concentration‐response curves (CRC's) to 5‐HT were monophasic. Only in collared segments the presence of a 5‐HT 2A antagonist (spiperone or ketanserin, 0.1 μ M ) revealed a biphasic CRC which was even more pronounced when a moderate tone was induced by KCl pointing to functional 5‐HT 1 ‐like receptors. The rabbit carotid artery constitutively expressed 5‐HT 1B and 5‐HT 2A mRNA, not 5‐HT 1D mRNA. Manipulation of the carotid artery increased the 5‐HT 1B mRNA level. Collar placement raised it even further. The 5‐HT 2A mRNA level remained unchanged. All the anti‐5‐HT receptor antibodies tested resulted in variable, non specific patterns with multiple bands. In conclusion, collar placement elevates mRNA expression and activity of the 5‐HT 1B receptor in the rabbit carotid artery.British Journal of Pharmacology (2000) 131 , 1723–1731; doi: 10.1038/sj.bjp.0703732