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 Vesselinovitch, S. D. Articles by Mihailovich, N. Search for Related Content PubMed PubMed Citation Articles by Vesselinovitch, S. D. Articles by Mihailovich, N.

The Neonatal and Infant Age Periods as Biologic Factors Which Modify Multicarcinogenesis by Urethan¹

Division of Oncology, Institute for Medical Research, The Chicago Medical School, Chicago, Illinois 60612

The objective of the present investigation was to determine whether various organs of mice possess the same carcinogenic response when treated repeatedly with urethan during only the infant period of life (7 days and older) or during the neonatal period (1st week of life) as well, and, if not, whether the susceptibility of older infants may be modified by priming with urethan during the newborn age period.

In the 1st part of the experiment, C57BL x C3H F₁ mice were given urethan 6 times at 3-day intervals. The treatments began on the 1st, 4th, or 7th day of life. Sixty weeks later the animals were killed. Several observations were made. First, the results of the experiment further documented the multicarcinogenicity of urethan as evidenced by the development of two types of ovarian tumors, Harderian gland adenomas, hepatomas, lung adenomas, and stem-cell malignant lymphomas (30, 31) in the treated animals. The development of the ovarian tumor is of particular interest as it adds another organ to those already known to be capable of being affected by urethan. Second, it was observed that the mice when 1st treated at 7 days of age developed hepatomas (females) and malignant lymphomas in a significantly lower proportion than did the mice which were first treated when newborn, but they developed Harderian gland adenomas in a higher proportion. On the other hand, the induction of ovarian tumors and lung adenomas was not affected by the age differences. It became apparent, then, that carcinogenesis in various tissues does change independently from one another shortly after birth.

In the 2nd part of the experiment the animals were given 6 urethan treatments at 3-day intervals delivered in two separate triads. The 1st set of treatments began on the 1st day of life (priming), while the 2nd triad followed the 1st triad after 9, 15, or 21 days. The incidence of malignant lymphomas, hepatomas (females), and Harderian gland adenomas decreased as the interruption of treatment increased. Thus the priming of newborns with urethan was ineffective in enhancing tumor response in the older infant mice.

¹ This investigation was supported by Contract PH 43-65-67 from the National Cancer Institute, NIH, USPHS. This paper was presented in part at the 9th International Cancer Congress, 1966, Tokyo, Japan.

Received 12/20/66. Accepted 4/ 7/67.