Membrane potential changes, cAMP stimulation and contraction in osteoblast-like UMR 106 cells in response to calcitonin and parathyroid hormone.
A multiphasic alteration in membrane potential occurs in response to calcitonin (CT), parathyroid hormone (PTH) and dibutyryl cAMP in the osteoblast-like UMR 106.01 and UMR 106.06 cell lines. This response consists of a small transient hyperpolarization, followed by a transient depolarization, followed by a long-term hyperpolarization. Experiments with channel blockers indicate that the depolarizing phase results from deactivation of K+ channels that are blocked by quinine but not by tetraethylammonium (TEA), and that the long-term hyperpolarization results from activation of K+ channels that are not blocked by quinine or by TEA. Correlating with the stimulation of intracellular cAMP by CT, a small percentage of the UMR 106.06 cells, but not UMR 106.01 cells, contract in response to CT. Both cell lines show a larger percentage of cells contracting in response to PTH than to CT.
Ferrier
J
J
Medical Research Council Group in Periodontal Physiology, Faculty of Dentistry, University of Toronto, Ontario, Canada.
Ward-Kesthely
A
A
Heersche
J N
JN
Aubin
J E
JE
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002116:Calcitonin / Q000494:pharmacology*; D002460:Cell Line; D015232:Dinoprostone / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D011803:Quinine / Q000494:pharmacology; D051381:Rats; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D010281:Parathyroid Hormone; D015221:Potassium Channels; D013757:Tetraethylammonium Compounds; D000001:Calcimycin; D003994:Bucladesine; D019789:Tetraethylammonium; D002116:Calcitonin; D011803:Quinine; D014700:Verapamil; D015232:Dinoprostone; D007545:Isoproterenol