Pertussis toxin blocks the inhibitory effects of calcitonin on cyclic AMP accumulation in stimulated cultured human monocytes.
Surface stimulation of fresh or cultured human mononuclear cells by latex particles causes an increase in the accumulation of cyclic AMP that is inhibited by preincubation with calcitonin (CT). Preincubation of cultured monocytes with 500 ng/ml pertussis toxin totally blocks the inhibitory effects of CT at low concentrations of this hormone. The effects of pertussis toxin are dose-related and eliminated by boiling the toxin. Similar preincubations with cholera toxin have no significant effects on subsequent inhibition of surface-stimulated cyclic AMP by CT. Membranes prepared from cultured human monocytes contain a 41,000-dalton protein that is ADP-ribosylated by pertussis toxin and may be the inhibitory guanine nucleotide regulatory protein (Ni) mediating this inhibition.
Stock
J L
JL
Endocrinology Research Laboratory, Worcester Memorial Hospital, Massachusetts 01605.
Coderre
J A
JA
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D002116:Calcitonin / Q000494:pharmacology*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002772:Cholera Toxin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis*; D006358:Hot Temperature; D006801:Humans; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; C028815:salmon calcitonin; D002116:Calcitonin; D002772:Cholera Toxin; D000242:Cyclic AMP; D037342:Pertussis Toxin