HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by WANG, D. Y. Articles by BULBROOK, R. D. Search for Related Content PubMed PubMed Citation Articles by WANG, D. Y. Articles by BULBROOK, R. D.

In experiments on the effect of insulin on the stimulation of incorporation of radioactive thymidine into the DNA of pregnant mouse mammary gland explants in culture, considerable variation between the results of successive experiments was noticed. Dependence of the extent of incorporation on the stage of pregnancy was investigated as a possible cause.

Cultures of explants of mammary gland were made (Trowell, 1959) from Schneider mice at various stages of their first pregnancy. The length of pregnancy was taken from the time of appearance of a vaginal plug. Insulin (Sigma Chemical Co., 24·1 i.u/mg.) was used at a concentration of 5 µg./ml. medium. After 24 hr. of incubation the cultures were pulsed for 4 hr. with [methyl-³H]thymidine (18·3 c/m-mole; Radiochemical Centre, Amersham) at a concentration of 0·5 µc/ml. medium (Stockdale & Topper, 1966). The tissue was removed and weighed, the acid-insoluble material hydrolysed (Mahin & Lofberg, 1966), and