PTH induces modification of transductive events in otosclerotic bone cell cultures.
We studied the effect of PTH (10-100 nM) on transductive mechanisms (adenylate cyclase activity, Ca2+ metabolism, IP3 levels) in cell cultures derived from normal and otosclerotic human bone fragments. The cultured cells were osteoblast-like but with calcitonin-receptors still present and with PTH receptors coupled with the adenylate cyclase system. The results showed that PTH activated adenylate cyclase and increased the intracellular Ca2+ levels with qualitative and quantitative differences between the two cellular populations. In particular, otosclerotic cells responded less to hormone stimulation, which is in accord with the current hypothesis of a desensitization of the receptor/enzyme complex associated with the pathological status.
Fanó
G
G
Istituto di Biologia Cellulare, Università di Perugia, Italy.
Venti-Donti
G
G
Belia
S
S
Paludetti
G
G
Antonica
A
A
Donti
E
E
Maurizi
M
M
D000262:Adenylyl Cyclases / Q000032:analysis; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D007295:Inositol Phosphates / Q000032:analysis; D010040:Otosclerosis / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*
D007295:Inositol Phosphates; D010281:Parathyroid Hormone; D000262:Adenylyl Cyclases; D002118:Calcium