TY - JOUR
T1 - Somatomedin C-binding and action in fibroblasts from aged and progeric subjects
AU - Conover, Cheryl A.
AU - Dollar, Laura A.
AU - Rosenfeld, Ron G.
AU - Hintz, Raymond L.
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1985/4
Y1 - 1985/4
N2 - Aging is associated with diminished cell growth, which has been ascribed in part to decreased cellular responsiveness to serum mitogens. To investigate whether there is an age-relatedloss of responsiveness to somatomediq-C (SM-C), we studied SM-C binding and action in early passage fibroblasts from normal donors, aged 7-96 yr, and one progeric subject. SM-C stimulated [3H]thymidine incorporation 4- to 16-fold in young cells, 4- to 17-fold in aged cells, and 4- to 11-fold in progeric cells. SM-C was synergistic with 0.25% human hypopituitary serum in stimulating [3H]thymidine incorporation in all cell lines. Dose-response curves for SM-C stimulation of thymidine incorporation were not significantly altered in aged or progeric cells. Half-maximal responses occurred at 5-15 ng/ml SM-C for all cell lines. [3H]Thymidine incorporation results were supported by cell replication studies. In addition, binding of [125I] SM-C was virtually identical in all cell lines, with 50% displacement at 2-5ng/ml SM-C. Thus, in vivo aging does not appear o t be associated with either an alteration in SM-C receptors or a diminished cellular responsiveness to SM-C’s mitogenic effects.
AB - Aging is associated with diminished cell growth, which has been ascribed in part to decreased cellular responsiveness to serum mitogens. To investigate whether there is an age-relatedloss of responsiveness to somatomediq-C (SM-C), we studied SM-C binding and action in early passage fibroblasts from normal donors, aged 7-96 yr, and one progeric subject. SM-C stimulated [3H]thymidine incorporation 4- to 16-fold in young cells, 4- to 17-fold in aged cells, and 4- to 11-fold in progeric cells. SM-C was synergistic with 0.25% human hypopituitary serum in stimulating [3H]thymidine incorporation in all cell lines. Dose-response curves for SM-C stimulation of thymidine incorporation were not significantly altered in aged or progeric cells. Half-maximal responses occurred at 5-15 ng/ml SM-C for all cell lines. [3H]Thymidine incorporation results were supported by cell replication studies. In addition, binding of [125I] SM-C was virtually identical in all cell lines, with 50% displacement at 2-5ng/ml SM-C. Thus, in vivo aging does not appear o t be associated with either an alteration in SM-C receptors or a diminished cellular responsiveness to SM-C’s mitogenic effects.
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U2 - 10.1210/jcem-60-4-685
DO - 10.1210/jcem-60-4-685
M3 - Article
C2 - 2579088
AN - SCOPUS:0021986114
SN - 0021-972X
VL - 60
SP - 685
EP - 691
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 4
ER -