This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by COHEN, K. L. Articles by NISSLEY, S. P. Search for Related Content PubMed PubMed Citation Articles by COHEN, K. L. Articles by NISSLEY, S. P.

Growth Hormone-Dependent Serum Stimulation of DNA Synthesis in Chick Embryo Fibroblasts in Culture^{1 ,2}

Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda Maryland 20014

Abstract

We have investigated the role of GH in the serum requirement for the multiplication of chick embryo fibroblasts (CEFs) in culture. Serum from hypophysectomized (hypox.) rats is much less effective than normal serum in stimulating the incorporation of [³H-methyl]thymidine into DNA. More importantly, bovine GH (bGH) treatment of the hypox. rat restores 60% or more of the activity in the ³H-thymidine incorporation assay. Bovine GH is inactive when tested directly in the assay. Mixing experiments show that the decreased activity of hypox. serum is not due to the presence of an inhibitor in the hypox. serum. The GH dependent factor is nondialysable and stable to boiling at pH 5.5. Boiling the normal, hypox. and bGH treated hypox. rat sera results not only in enhancement of the activity but also a more linear dose response curve in the ³H-thymidine incorporation assay. The ³H-thymidine incorporation data reflect DNA synthesis because measurements of cell numbers show the CEFs multiply less well in boiled hypox. rat serum than in boiled normal rat serum, and bGH treatment of the hypox. rat restores approximately half of the multiplication stimulating activity of normal boiled rat serum. CEFs in culture may provide a satisfactory in vitro system for the study of the mechanism of action of the growth hormone dependent anabolic factors found in serum. (Endocrinology 96: 193, 1975)

Footnotes

¹ A report of part of these findings appeared as an abstract in Clinical Research XXII, No. 3, 46A, 1974.

² Abbreviations used are: CEFs, chicken embryo fibroblasts; hypox., hypophysectomized; bGH, bovine GH; ³H-thymidine, [³H-methyl]thymidine; MSA, multiplication stimulating activity, NSILA-S, acid ethanol-soluble nonsuppressible insulin-like activity; E, Temin/s modified Eagle/s minimal essential medium.

Received July 22, 1974.

This article has been cited by other articles:

				Z. Nevo and Z. Laron Growth Factors Arch Pediatr Adolesc Med, April 1, 1979; 133(4): 419 - 428. [Abstract] [PDF]