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Testing of formaldehyde in the mammalian spot test by inhalation
266 73 Jensen, N.J., and K.-H. Cohr, Institute of Toxicology, National Food Institute, 19, Morkhoj Bygade, DK-2860 Soborg and Institute of Occupational Health, 73, Bauneghrdsvej, DK-2900 Hellerup (Denmark)
Testing of formaldehyde in the mammalian spot test by inhalation The health hazards of formaldehyde, which is one of the most wide-spread compounds in the human environment, has recently been reviewed by Niemel~i and Vainio (Scand. J. Work Environ. Health, 7 (1981) 95-100). Among the potential risks to man are mutagenicity and carcinogenicity. On days 8, 9 and 10 of pregnancy female C57BL/6J Han mated to T-stock mice were exposed to formaldehyde gas in a 15.4 m3 dynamic exposure chamber, 10 air changes/h, 20-22°C, and R.H. 57-62%. Two groups were exposed 6 h a day to formaldehyde concentrations of 6.0-6.1 + 0.04 and 17.8-18.1 + 0.1 (S.D.) m g / m 3 respectively. ENU 20 mg i.p./kg b.w./day for 3 days served as positive control and both a solvent control and an undosed control group were used. The results were (number of offspring/number with recessive spots): undosed control 220/3, solvent control 315/2, ENU 184/58, formaldehyde 6 m g / m 3 163/3 and formaldehyde 18 m g / m 3 222/2. No significant increase in recessive spots was found in the offspring of mice exposed to formaldehyde compared to the controls, whereas ENU increased the number significantly. Thus formaldehyde was negative in the mammalian spot test. Negative results should always be considered in the light of the pharmacodynamic possibility that the active compound does not reach the foetus. Further studies on the distribution of the active compound(s) across the placental barrier are needed before conclusion of the in vivo mutagenic potential can be stated.
74 Kappas, A., Biology Department, Nuclear Research Center 'Democritus', Athens (Greece)
Plant growth-regulating hormones induce mitotic segregation in Aspergillus nidulans Three growth-regulating hormones, indole-3-acetic acid (IAA), indole-3-butyric acid, and kinetin (6-furfurylaminopurine), were tested and the first two were found to greatly increase the somatic segregation in the ascomycete Aspergillus nidulans whereas kinetin was not effective. A properly marked diploid strain heterozygous for yellow and white colour conidia was used and the segregation was scored as colour sectors in green colonies grown on complete medium containing the chemicals. Several concentrations of the plant hormones were used and it was found that with increasing the concentrations of IAA and indole-3-butyric acid, increased segrega-
Testing of formaldehyde in the mammalian spot test by inhalation The health hazards of formaldehyde, which is one of the most wide-spread compounds in the human environment, has recently been reviewed by Niemel~i and Vainio (Scand. J. Work Environ. Health, 7 (1981) 95-100). Among the potential risks to man are mutagenicity and carcinogenicity. On days 8, 9 and 10 of pregnancy female C57BL/6J Han mated to T-stock mice were exposed to formaldehyde gas in a 15.4 m3 dynamic exposure chamber, 10 air changes/h, 20-22°C, and R.H. 57-62%. Two groups were exposed 6 h a day to formaldehyde concentrations of 6.0-6.1 + 0.04 and 17.8-18.1 + 0.1 (S.D.) m g / m 3 respectively. ENU 20 mg i.p./kg b.w./day for 3 days served as positive control and both a solvent control and an undosed control group were used. The results were (number of offspring/number with recessive spots): undosed control 220/3, solvent control 315/2, ENU 184/58, formaldehyde 6 m g / m 3 163/3 and formaldehyde 18 m g / m 3 222/2. No significant increase in recessive spots was found in the offspring of mice exposed to formaldehyde compared to the controls, whereas ENU increased the number significantly. Thus formaldehyde was negative in the mammalian spot test. Negative results should always be considered in the light of the pharmacodynamic possibility that the active compound does not reach the foetus. Further studies on the distribution of the active compound(s) across the placental barrier are needed before conclusion of the in vivo mutagenic potential can be stated.
74 Kappas, A., Biology Department, Nuclear Research Center 'Democritus', Athens (Greece)
Plant growth-regulating hormones induce mitotic segregation in Aspergillus nidulans Three growth-regulating hormones, indole-3-acetic acid (IAA), indole-3-butyric acid, and kinetin (6-furfurylaminopurine), were tested and the first two were found to greatly increase the somatic segregation in the ascomycete Aspergillus nidulans whereas kinetin was not effective. A properly marked diploid strain heterozygous for yellow and white colour conidia was used and the segregation was scored as colour sectors in green colonies grown on complete medium containing the chemicals. Several concentrations of the plant hormones were used and it was found that with increasing the concentrations of IAA and indole-3-butyric acid, increased segrega-