1 In a previous experiment, using 32P as a potential transplacental carcinogen in rats, we found that the isotope caused life-span shortening, reduced growth and caused ante-dating of the time of the tumour occurrence.
2 Liver cell changes (nuclear atypia, variation in cell size) were noted and suggested liver cell damage, possible 'initiation'.
3 A phorbol ester (TPA) and a high fat/high protein diet were used as promoting agents on further transplacentally irradiated rats.
4 The results were identical to the previous experiment; no evidence of promotion was found.
References
1.
Berman, J.J. , Tong, C. & Williams, G.M. (1978). Enhancement of mutogenesis during cell replication of cultured liver epithelial cells. Cancer Lett., 4, 277.
2.
Berry, C.L. , Amerigo, J., Nickols, C. & Swettenham, K.V. (1983). Transplacental carcinogenesis with radioactive phosphorus. Human Toxicol., 2, 49-62.
3.
Bull, A.Q. , Soullier, B.K., Wilson, P.S., Hayden, M.T. & Nigro, N.D. (1979). Promotion of azoxymethane-induced intestinal cancer by high fat diet in rats. Cancer Res., 39, 4956-4959.
4.
Cohen, R. , Pacifici, M., Rubinstein, N., Biehl, J. & Holtzer, H. (1977). Effect of a tumour promoter on myogenesis. Nature, 266, 538-540.
5.
Conybeare, G. (1980). Effects of quality and quantity of diet on survival and tumour incidence in outbred Swiss mice. Food Cosmet. Toxicol. , 18, 65.
6.
Date, P.A. , Gothoskar, S.V. & Bhide, S.V. (1976). Effect of partial hepatectomy on tumour incidence and metabolism of mice after thioacetamide. J. Natl. Cancer Inst., 56, 493-497.
7.
Diamond, L. , O'Brien, T.G. & Rovera, R. (1977). Inhibition of adipose conversion of 3T3 fibroblasts by tumour promoters. Nature, 269, 247-249.
8.
Goerttler, K. & Loehrke, H. (1976a). Diaplacental carcinogenesis: Initiation with the carcinogens Dimethylbenzanthracene (DMBA) and Urethrane during fetal life and postnatal promotion with the phorbol ester TPA in a modified 2-stage Berenblum/Mottram experiment. Virchows Archiv. A., 372, 29-38.
9.
Goertller, K. & Loehrke, H. (1976b). Trans-maternal variation of the Berenblum experiment with NMRI-mice. Virchows Archiv. A., 370, 97-102.
10.
Goerttler, K. , Loehrke, H., Schweizer, J. & Bigitte, H. (1980). Positive two-stage carcinogenesis in female Sprague-Dawley rats using 7,13-Dimethylbenz(a) Anthracene (DMBA) as initiator and 12-0-Tetradecanoylphorbol-13-Acetate (TPA) as promoter. Virchows Archiv. A., 385, 181-186.
11.
McCormick, J.J. (1979). Evidence that DNA excision repair processes in human fibroblasts can eliminate potentially cytotoxic and mutagenic lesions . (Abstr.) 10th Annual Meeting, Environmental Mutagen Society, New Orleans, Louisianna , USA, March 8-12.
12.
Ohde, G. , Schuppler, J., Schulte-Hermann, R. & Keiger, H. (1979). Proliferation of rat liver cells in preneoplastic nodules after stimulation of liver growth by Xenobiotic inducers. Arch. Toxicol. Suppl. 2, Mechanism of Toxic Action on Some Target Organs, 451-455.
13.
Reddy, J.K. , Rao, M.S. & Jago, M.V. (1976). Rapid development of hyperplastic nodules and cirrhosis in the liver of rats treated concurrently with thioacetamide and the pyrrolizidine alkaloid lasiocarpine. Int. J. Cancer, 17, 621-625.
14.
Rao, M.S. , Jago, M.V. & Reddy, J.K. (1983). Effect of calorie restriction on the fate of hyperplastic liver nodules induced by concurrent administration of lasiocarpine and thioacetamide . Human Toxicol., 2, 15-26.
15.
Schulte-Hermann, R. (1979). Adaptive liver growth induced by Xenobiotic compounds: Its nature and mechanism. Arch. Toxicol. Suppl.2, Mechanism of Toxic Action on Some Target Organs, 113-124.
16.
Tucker, M.J. (1979). The effect of long term food restriction on tumours in rodents. Int. J. Cancer, 23, 803.
17.
Weymouth, L.A. & Loeb, L.A. (1978). Mutagenesis during in vitro DNA synthesis. Proc. Natl. Acad. Sci. USA, 75, 1924.
