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Effect of hematoporphyrin and light on human lymphocytes in vitro
222 Furocoumarins having an angular molecular structure, like angeticin derivatives, behave as monofunctional reagents, forming only monoadduc~s; linear furocoumarins, i.e. psoralen derivatives, form monoadducts and diadducts giving in the latter case interstrand cross-links. When tested for their ability to induce mutations at the H G P R T locus in V79 Chinese hamster cells in culture, both linear and angular furocoumarins gave numbers of mutants significantly higher than controls after activation by near-UV light doses, which did n o t impair cell survival. The authors thank Prof. F. Bordin, University of Padua, for supplying furocoumarins. 107 D.H. Waalkens, H.F.P. Joosten, R. Taalman 1, J.M.J.C. Scheres i T.D. Yih and A. Hoekstra, Dept. o f Reproductive Toxicology, Organon Int. B . V , Oss~ and ' Dept. of Human Genetics, Medical Faculty, Univ. of Nijmegen (The Netherlands) The usefulness o f cultured l y m p h o c y t e s from different mammalian species for the determination of SCEs induced b y MMS and cyclophosphamide Methyl methanesulphonate (MMS), a direct mutagen, and cyclophosphamide, an indirect mutagen, were used to determine the utility of cultured lymphocytes in the sister-chromatid exchange test. The results show that both c o m p o u n d s can induce SCEs in l y m p h o c y t e s of man, rat and rabbit° With respect to cyclophosphamide, which is k n o w n to require metabolic activation, this is in contrast with the results o f Perry and Evans (1975) and De Raat (1977) w h o measured no increase in the yield of SCEs in CHO cells, without activation. Moreover, preliminary results demonstrated that cyclophosphamide increases the yield of SCEs, w i t h o u t exogenous activation, in rat ascites cells~ Chinese hamster embryonic cells, and human embryonic fibroblasts, which contain mixed function oxidases (see Wolff and Carrano, 1979). Our results suggest that culture l y m p h o c y t e s also contain the enzymes required for metabolic activation of cyclophosphamide. Furthermore, the mean number of SCEs per metaphase was a b o u t twice as high in control l y m p h o c y t e s from man as in those from rat and rabbit. It is therefore supposed t h a t the sensitivity of this test system using human l y m p h o c y t e s is less than if rat or rabbit lymphocytes are used. Nevertheless the utility of cultured l y m p h o c y t e s in SCE testing seems to be promising, because of the great sensitivity and the ease with which this test can be performed. 108 H. Waksvik, J. Moan and T. Christensen, Norsk Hydro's Institute for Cancer Research, Oslo {Norway)
Effect o f h e m a t o p o r p h y r i n and light on human lymphocytes in vitro P h o t o c h e m o t h e r a p y in the presence of hematoporphyrin derivatives is a promising possibility in cancer therapy. This study was undertaken to test
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whether treatment with hematoporphyrin and light had any effects on the chromosomes. Human lymphocytes, cultivated in vitro, were exposed to hematoporphyrin and light, and assayed for the effect upon cell division and sister-chromatid exchange. The treatment resulted in a division delay, possibly also an inactivation of a fraction of the lymphocytes. No increased frequency of sister-chromatid exchanges was observed in the irradiated cells compared to control cells. 109 I.-D. Adler 1, G. Fekete 2 and K. Fagan 1, 1 Gesellschaft ffir Strahlen- und Umweltforschung, D-8042 Neuherberg (Federal Republic of Germany), and 2 Department of Pediatrics No. 2, Semmelweis University Medical School, Budapest (Hungary) Chemically induced heritable translocations in the mouse The conventional protocol of the heritable translocation test requires fertility testing for selection of suspect translocation carriers. Male and female progeny of treated parents can be tested. The criteria for the definition of normal and translocation suspect animals have been previously described (Mutation Res., 53 (1978) 143--144). A recently developed protocol is based on cytogenetic analysis of all F~ sons of treated parents (Biol. Zbl., 97 (1978) 441--451). Both methods have been compared in a radiation experiment and were found to be equally sensitive but the cytogenetic test was less time consuming. Using the conventional protocol 1.3% (7 among 546 F1) translocations were found after treatment of spermatids with 20 mg/kg methyl methanesulfonate. Mitomycin C (MC) was tested with the conventional and the cytogenetic protocol. After treatment of spermatids and spermatocytes with 2.5 mg/kg MC, 0.3% translocations were found among the progeny (5 out of 1475 F1 vs 0 out of 1400 F1; P = 0.04). In a current experiment with 400 mg/kg Natulan® 2.5% translocations (5 out of 202 F~) were so far identified among progeny from treated spermatids with the cytogenetic protocol only. A number of translocation lines were established from these experiments. The translocation chromosomes for most of these lines have been identified by Giemsa banding. R e s e a r c h p e r f o r m e d u n d e r t h e EEC C o n t r a c t N o . 1 3 6 - 7 7 - 1 E N V D.
110 D. Anderson and C.R. Richardson, Central Toxicology Laboratory, ICI, Alderley Park, Macclesfield, Cheshire (United Kingdom) Issues relevant to the assessment of chemically induced chromosome damage in vivo and their relationship to chemical mutagenesis Rats have been exposed by different routes of administration (inhalation, orally and intraperitoneally) to known mutagens and their bone marrow cells
Effect o f h e m a t o p o r p h y r i n and light on human lymphocytes in vitro P h o t o c h e m o t h e r a p y in the presence of hematoporphyrin derivatives is a promising possibility in cancer therapy. This study was undertaken to test
223
whether treatment with hematoporphyrin and light had any effects on the chromosomes. Human lymphocytes, cultivated in vitro, were exposed to hematoporphyrin and light, and assayed for the effect upon cell division and sister-chromatid exchange. The treatment resulted in a division delay, possibly also an inactivation of a fraction of the lymphocytes. No increased frequency of sister-chromatid exchanges was observed in the irradiated cells compared to control cells. 109 I.-D. Adler 1, G. Fekete 2 and K. Fagan 1, 1 Gesellschaft ffir Strahlen- und Umweltforschung, D-8042 Neuherberg (Federal Republic of Germany), and 2 Department of Pediatrics No. 2, Semmelweis University Medical School, Budapest (Hungary) Chemically induced heritable translocations in the mouse The conventional protocol of the heritable translocation test requires fertility testing for selection of suspect translocation carriers. Male and female progeny of treated parents can be tested. The criteria for the definition of normal and translocation suspect animals have been previously described (Mutation Res., 53 (1978) 143--144). A recently developed protocol is based on cytogenetic analysis of all F~ sons of treated parents (Biol. Zbl., 97 (1978) 441--451). Both methods have been compared in a radiation experiment and were found to be equally sensitive but the cytogenetic test was less time consuming. Using the conventional protocol 1.3% (7 among 546 F1) translocations were found after treatment of spermatids with 20 mg/kg methyl methanesulfonate. Mitomycin C (MC) was tested with the conventional and the cytogenetic protocol. After treatment of spermatids and spermatocytes with 2.5 mg/kg MC, 0.3% translocations were found among the progeny (5 out of 1475 F1 vs 0 out of 1400 F1; P = 0.04). In a current experiment with 400 mg/kg Natulan® 2.5% translocations (5 out of 202 F~) were so far identified among progeny from treated spermatids with the cytogenetic protocol only. A number of translocation lines were established from these experiments. The translocation chromosomes for most of these lines have been identified by Giemsa banding. R e s e a r c h p e r f o r m e d u n d e r t h e EEC C o n t r a c t N o . 1 3 6 - 7 7 - 1 E N V D.
110 D. Anderson and C.R. Richardson, Central Toxicology Laboratory, ICI, Alderley Park, Macclesfield, Cheshire (United Kingdom) Issues relevant to the assessment of chemically induced chromosome damage in vivo and their relationship to chemical mutagenesis Rats have been exposed by different routes of administration (inhalation, orally and intraperitoneally) to known mutagens and their bone marrow cells