Somatomedin C/insulin-like growth factor I binding and action in human fibroblasts aged in culture: Impaired synergism with dexamethasone

C. A. Conover, Ronald (Ron) Rosenfeld, R. L. Hintz

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Somatomedin C/insulin-like growth factor I (SM-C/IGF-I) binding and action were compared in human fibroblasts serially passaged in vitro. Binding of [125I]SM-C/IGF-I was identical in early and late passage cells, with 50% displacement at 4 ng/ml SM-C/IGF-I. Maximal concentrations of SM-C/IGF-I (100 ng/ml) stimulated [3H]thymidine incorporation equally in both early and late passage cells. Furthermore, dose response curves indicated that there was no alteration in the sensitivity of cells to SM-C/IGF-I with age. Preincubation with dexamethasone (10-7 M) potentiated SM-C/IGF-I's mitogenic effect in early passage cells. In contrast, dexamethasone had no effect on SM-C/IGF-I stimulation of [3H]thymidine incorporation or replication of late passage cells. These data indicate that fibroblasts passaged in vitro have normal SM-C/IGF-I binding and are capable of responding to the mitogenic effect of SM-C/IGF-I. The synergism between SM-C/IGF-I and dexamethasone in stimulating DNA synthesis and replication of early passage fibroblasts is lost, however, in late passage cells.

Original languageEnglish (US)
Pages (from-to)308-314
Number of pages7
JournalJournals of Gerontology
Volume42
Issue number3
StatePublished - 1987
Externally publishedYes

Fingerprint

Insulin-Like Growth Factor I
Dexamethasone
Fibroblasts
Thymidine
DNA Replication

ASJC Scopus subject areas

  • Aging

Cite this

Somatomedin C/insulin-like growth factor I binding and action in human fibroblasts aged in culture : Impaired synergism with dexamethasone. / Conover, C. A.; Rosenfeld, Ronald (Ron); Hintz, R. L.

In: Journals of Gerontology, Vol. 42, No. 3, 1987, p. 308-314.

Research output: Contribution to journalArticle

@article{77c022cce3924b9b92f461e6d310c2b8,
title = "Somatomedin C/insulin-like growth factor I binding and action in human fibroblasts aged in culture: Impaired synergism with dexamethasone",
abstract = "Somatomedin C/insulin-like growth factor I (SM-C/IGF-I) binding and action were compared in human fibroblasts serially passaged in vitro. Binding of [125I]SM-C/IGF-I was identical in early and late passage cells, with 50{\%} displacement at 4 ng/ml SM-C/IGF-I. Maximal concentrations of SM-C/IGF-I (100 ng/ml) stimulated [3H]thymidine incorporation equally in both early and late passage cells. Furthermore, dose response curves indicated that there was no alteration in the sensitivity of cells to SM-C/IGF-I with age. Preincubation with dexamethasone (10-7 M) potentiated SM-C/IGF-I's mitogenic effect in early passage cells. In contrast, dexamethasone had no effect on SM-C/IGF-I stimulation of [3H]thymidine incorporation or replication of late passage cells. These data indicate that fibroblasts passaged in vitro have normal SM-C/IGF-I binding and are capable of responding to the mitogenic effect of SM-C/IGF-I. The synergism between SM-C/IGF-I and dexamethasone in stimulating DNA synthesis and replication of early passage fibroblasts is lost, however, in late passage cells.",
author = "Conover, {C. A.} and Rosenfeld, {Ronald (Ron)} and Hintz, {R. L.}",
year = "1987",
language = "English (US)",
volume = "42",
pages = "308--314",
journal = "Journal of Gerontology: Social Sciences",
issn = "0022-1422",
publisher = "Gerontological Society of America",
number = "3",

}

TY - JOUR

T1 - Somatomedin C/insulin-like growth factor I binding and action in human fibroblasts aged in culture

T2 - Impaired synergism with dexamethasone

AU - Conover, C. A.

AU - Rosenfeld, Ronald (Ron)

AU - Hintz, R. L.

PY - 1987

Y1 - 1987

N2 - Somatomedin C/insulin-like growth factor I (SM-C/IGF-I) binding and action were compared in human fibroblasts serially passaged in vitro. Binding of [125I]SM-C/IGF-I was identical in early and late passage cells, with 50% displacement at 4 ng/ml SM-C/IGF-I. Maximal concentrations of SM-C/IGF-I (100 ng/ml) stimulated [3H]thymidine incorporation equally in both early and late passage cells. Furthermore, dose response curves indicated that there was no alteration in the sensitivity of cells to SM-C/IGF-I with age. Preincubation with dexamethasone (10-7 M) potentiated SM-C/IGF-I's mitogenic effect in early passage cells. In contrast, dexamethasone had no effect on SM-C/IGF-I stimulation of [3H]thymidine incorporation or replication of late passage cells. These data indicate that fibroblasts passaged in vitro have normal SM-C/IGF-I binding and are capable of responding to the mitogenic effect of SM-C/IGF-I. The synergism between SM-C/IGF-I and dexamethasone in stimulating DNA synthesis and replication of early passage fibroblasts is lost, however, in late passage cells.

AB - Somatomedin C/insulin-like growth factor I (SM-C/IGF-I) binding and action were compared in human fibroblasts serially passaged in vitro. Binding of [125I]SM-C/IGF-I was identical in early and late passage cells, with 50% displacement at 4 ng/ml SM-C/IGF-I. Maximal concentrations of SM-C/IGF-I (100 ng/ml) stimulated [3H]thymidine incorporation equally in both early and late passage cells. Furthermore, dose response curves indicated that there was no alteration in the sensitivity of cells to SM-C/IGF-I with age. Preincubation with dexamethasone (10-7 M) potentiated SM-C/IGF-I's mitogenic effect in early passage cells. In contrast, dexamethasone had no effect on SM-C/IGF-I stimulation of [3H]thymidine incorporation or replication of late passage cells. These data indicate that fibroblasts passaged in vitro have normal SM-C/IGF-I binding and are capable of responding to the mitogenic effect of SM-C/IGF-I. The synergism between SM-C/IGF-I and dexamethasone in stimulating DNA synthesis and replication of early passage fibroblasts is lost, however, in late passage cells.

UR - http://www.scopus.com/inward/record.url?scp=0023635773&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023635773&partnerID=8YFLogxK

M3 - Article

C2 - 3571867

AN - SCOPUS:0023635773

VL - 42

SP - 308

EP - 314

JO - Journal of Gerontology: Social Sciences

JF - Journal of Gerontology: Social Sciences

SN - 0022-1422

IS - 3

ER -