Growth-promoting actions of parathyroid hormone, adrenocorticotrophic hormone, and thyroid-stimulating hormone: in vitro studies in normal and pygmy T-lymphoblast cell lines.
We used an in vitro T-lymphoblast clonal proliferation assay to quantify human IGF-I (hIGF-I)-, human PTH (hPTH)-, human ACTH (hACTH)-, and human TSH (hTSH)-stimulated growth of human T-cell leukemia virus-II-transformed T-lymphoblast cell lines from normal individuals and to elucidate the role of IGF-I as the mediator of hPTH-, hACTH-, and hTSH-induced T-cell growth. Normal T-lymphoblast cell lines respond to hIGF-I in a bimodal fashion. The mean first peak response was 143 +/- 9.8% above baseline (defined as 100%) occurring at 8 micrograms/L, and the mean second peak response was 154 +/- 14.4% occurring at 100 micrograms/L. Both responses were completely blocked after incubation with alpha IR-3, an MAb to the IGF-I receptor (by analysis of variance, p = 0.015 between full response curves). After stimulation with hPTH, the mean peak clonal response of normal T-lymphoblast cell lines was 189 +/- 7.0%; after incubation with alpha IR-3, the mean peak clonal response was 108 +/- 7.9% (p = 0.0015 between full response curves). The mean peak clonal response of normal T-lymphoblast cell lines after hACTH stimulation was 192 +/- 8.6%; preincubation with alpha IR-3 reduced the mean peak clonal response to 94 +/- 1.2% (p < 0.0001 between full response curves). With hTSH stimulation, the mean peak clonal response of normal T-lymphoblast cell lines was 167 +/- 7.0%; after incubation with alpha IR-3, the mean peak clonal response was 94 +/- 8.2% (p = 0.003 between full response curves).(ABSTRACT TRUNCATED AT 250 WORDS)
Geffner
M E
ME
Department of Pediatrics, University of California at Los Angeles 90024, USA.
Bersch
N
N
Cortez
A B
AB
Bailey
R C
RC
Golde
D W
DW
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000328:Adult; D044383:Black People; D001827:Body Height / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D015367:Human T-lymphotropic virus 2; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D012016:Reference Values; D015203:Reproducibility of Results; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000187:drug effects*; D013972:Thyrotropin / Q000494:pharmacology*
D010281:Parathyroid Hormone; D007334:Insulin-Like Growth Factor I; D000324:Adrenocorticotropic Hormone; D013972:Thyrotropin