Alpha 2- and beta-adrenergic receptors and adenosine A1 receptor of FRTL-5 rat thyroid cells in relation to fucosyl GM1 ganglioside.
We have previously reported that anti-fucosyl GM1 ganglioside antibody partially suppresses cAMP production in FRTL-5 rat thyroid cells not via the TSH receptor but via guanine nucleotide-binding protein indirectly. In order to clarify further the mechanism of the antibody action, we studied the relationship with alpha 2- and beta-adrenergic and adenosine A1 receptors. FRTL-5 cells did not bind [3H]clonidine, suggesting the lack of alpha 2-adrenergic receptor or at least abnormality of its binding domain. On the other hand, the cells specifically bound [125I]iodocyanopindolol, but isoproterenol failed to affect the basal and TSH-stimulated cAMP production indicating the lack of coupling with adenylate cyclase. The inhibition of cAMP production induced by anti-fucosyl GM1 antibody was not altered by adrenergic agents. [125I]hydroxyphenylisopropyl adenosine binding was observed in FRTL-5 cells but was not displaced by the antibody. These results lead to conclusions that FRTL-5 cells lack alpha 2-adrenergic receptor but have beta-adrenergic receptor which lacks coupling with adenylate cyclase and have adenosine A1 receptor, and that the adrenergic receptors and adenosine A1 receptor are not the site of action of anti-fucosyl GM1 antibody.
Kosugi
S
S
Department of Internal Medicine, Kyoto University School of Medicine, Japan.
Mori
T
T
Iwamori
M
M
Nagai
Y
Y
Imura
H
H
D000818:Animals; D002460:Cell Line; D003000:Clonidine / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D005677:G(M1) Ganglioside / Q000031:analogs & derivatives* / Q000502:physiology; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D011983:Receptors, Purinergic / Q000378:metabolism*; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism*; D013972:Thyrotropin / Q000494:pharmacology; D015016:Yohimbine / Q000494:pharmacology
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D011983:Receptors, Purinergic; D015016:Yohimbine; D005677:G(M1) Ganglioside; C039123:fucosyl GM1 ganglioside; D013972:Thyrotropin; D000242:Cyclic AMP; D007545:Isoproterenol; D003000:Clonidine