Electrical responses of cultured porcine thyroid cells to adrenergic agents

in Journal of Endocrinology
Authors:
P. A. McGrath
Search for other papers by P. A. McGrath in
Current site
Google Scholar
PubMed
Close
,
J. R. Bourke
Search for other papers by J. R. Bourke in
Current site
Google Scholar
PubMed
Close
,
G. J. Huxham
Search for other papers by G. J. Huxham in
Current site
Google Scholar
PubMed
Close
, and
S. W. Manley
Search for other papers by S. W. Manley in
Current site
Google Scholar
PubMed
Close
Restricted access
Rent on DeepDyve

Sign up for journal news

ABSTRACT

The membrane potential of cultured porcine thyroid follicular cells depolarized by up to 20 mV from the resting value of about − 73 mV on exposure to β-adrenoceptor agonists. A similar response was induced by TSH or dibutyryl cyclic AMP. α-Adrenoceptor agonists were without effect. The receptor subtype was shown to be (at least predominantly) β2 by the order of potency for β-agonists (isoprenaline ≅ fenoterol⪢adrenaline >noradrenaline) and by the relative potency of selective β-antagonists (ICI 118,551 ⪢atenolol). The α-agonist phenylephrine had no effect on the TSH response but weakly inhibited the β-agonist response. Rather than a physiological antagonism between α- and β-adrenoceptor-mediated responses, this effect was shown to be due to the weak β-antagonist effect of phenylephrine since the α-antagonist phentolamine failed to potentiate the depolarizing response to the mixed agonist nor-adrenaline, and also failed to block the inhibitory action of phenylephrine on the β-agonist effect. Sensitivity to β-agonist was enhanced by omission of serum from the culture medium and reduced by exposure to β-agonists or a high concentration of TSH or dibutyryl cyclic AMP.

J. Endocr. (1985) 107, 23–30

 

  • Collapse
  • Expand