Search PubMed⌕ Search

Biomedical subjects

C Grandjean

Publications and source records attributed to C Grandjean.

32 records · Page 2Linked to original sources
PubMed1977

Transplacental effect of nitrosamines in Syrian hamsters. IV. Metabolites of dipropyl- and dibutylnitrosamine.

The present investigations showed that assumed and established metabolites of dipropylnitrosamine and dibutylnitrosamine reach the Syrian hamster fetus after subcutaneous (s.c.) treatment of their mothers (at day 14 of gestation). The compounds [2-hydroxypropylpropylnitrosamine, HPPN; 2-oxopropylpropylnitrosamine, OPPN; methylpropylnitrosamine, MPN; N-nitrosobis(2-hydroxypropyl)amine, BHP; and 4-hydroxybutylbutylnitrosamine, HBBN] were still present in the examined tissue (maternal blood, placenta, fetus, amniotic fluid) 4--6 h after s.c. injection. The overall incidence of transplacentally induced tumors was lower in the F1- than in the P-generation and comparatively longer latencies were also observed in the F1- generation. However, in some groups low incidences were found of tumors which did not occur in the mothers (i.e., nasal cavities: BHP, HBBN; trachea: HBBN; lungs: HPPN, BHP, HBBN; liver: OPN, MPN, BHP, HBBN). Compared to exposure at early gestation, the transplacental carcinogenic effect increased at day 14 of gestation. Neoplasms originating in other organs were not associated with a transplacental effect of the examined nitrosamines.

Amniotic Fluid↗
PubMed1977

Local and systemic effects of 1-acetoxypropylpropylnitrosamine in Syrian golden hamsters.

1-Acetoxypropylpropylnitrosamine (1-APPN) was synthesized and its biological effect examined in Syrian hamsters after subcutaneous (s.c.) administration. 1-APPN induced mesenchymal and epithelial neoplasms at the injection sites, as well as epithelial tumors in remote organs. Local neoplasms were a.c. sarcomas, mammary adenocarcinomas and Schwannomas, whereas tumors of the respiratory tract (papillary polyps, papillomas, adenomas, epidermoid carcinomas, and adenocarcinomas) were attributed to a systemic effect as were pancreas duct tumors. Neoplasms which originated in the upper digestive and genital tracts of females (papillomas, epidermoid carcinomas) may be related to a systemic and local effect of 1-APPN.

Animals↗
PubMed1977

Comparison of the effect of beta-oxidized dipropylnitrosamine metabolites administered at equimolar doses to Syrian hamsters.

After subcutaneous administration of dipropylnitrosamine (DPN) to Syrian hamsters, gas-liquid chromatographic analysis of the 16-h urine revealed the DPN metabolites, 2-hydroxypropyl-, 2-oxopropyl-, and methylpropylnitrosamines. In a related series of experiments, hamsters received equimolar doses of the above compounds and of N-nitrosobis(2-hydroxypropyl)-amine (BHP) and 2,2'-dimethyldipropylnitrosamine (DMDPN). The metabolites as well as BHP and DMDPN had a weaker effect than did DPN on the rate and/or latency of respiratory tumors. In the respiratory tract, the segmental tumor distribution and histological types varied according to the compounds. The metabolites of DPN induced additional tumors in the digestive tract. These experiments do not support the concept that the beta-oxidized metabolites of DPN are the proximate carcinogens of the parent compound.

Animals↗
PubMed1977

Transplacental effects of nitrosamines in Syrian hamsters. II. Nitrosopiperidine.

Nitrosopiperidine (NP) was found in Syrian hamsters quantitatively in the maternal blood for more than 8 h after subcutaneous injection, whereas it disappeared from placenta, fetus and amniotic fluid within the same time period. For N6MI, only traces were seen after 2 h in the same tissues. The long-term transplacental effect of a single dose of NP was weak, as demonstrated by a low respiratory tract tumor incidence (P-generation: 54%, F1- generation: 4%). Some tumors occurring in the digestive tract of exposed young were not found in their mothers and not commonly observed in controls. These tumors were considered a borderline transplacental effect. Tumors of other sites (i.e., the urogenital and genital tracts, reticuloendothelial system, endocrine organs and other tissues) corresponded in incidences to the overall fluctuations observed in this hamster colony.

Animals↗
PubMed1977

Transplacental effects of nitrosamines in Syrian hamsters. III. Dimethyl- and dipropylnitrosamine.

The aliphatic nitrosamines dimethylnitrosamine (DMN), diethylnitrosamine (DEN), dipropylnitrosamine (DPN), and dibutylnitrosamine (DBN) reached fetal tissue in quantitatively measurable amounts after subcutaneous administration to pregnant Syrian hamsters. The compounds were present for at least 2 h in maternal blood, placenta, fetus, and amniotic fluid; DBN was still measurable after 6 h. Only a weak or borderline transplacental effect was seen when incidences and latencies of neoplasms in the respiratory and digestive tracts of the F1-generation were compared with those of the P-generation after exposure to a single dose of DMN or DPN. However, some tumor types occurred at relatively high rates in the young, but were seen only occcasionally in their mothers or in this hamster colony in general.

Amniotic Fluid↗
PubMed1977

Vinylethylnitrosamine: a potent respiratory carcinogen in Syrian hamsters.

Vinylethylnitrosamine (VEN), an alpha-beta unsaturated analogue of diethylnitrosamine (DEN), which may be formed by the enzymic conversion necessary for carcinogenesis, was synthesized and its biologic effect was examined by sc administration to Syrian hamsters. Distribution studies showed that the maximum amount of unaltered compound was found in various tissues 45 minutes after injection. The chemical was only partially excreted unchanged after 5 hours. Weekly treatment for life resulted in high incidence of malignant respiratory tract neoplasms with short latencies and in tumors of the upper digestive tract and pancreas. The effects of VEN were compared to those of the assumed parent compound, DEN.

Animals↗
PubMed1977

Diallylnitrosamine: a potent respiratory carcinogen in Syrian golden hamsters: brief communication.

Diallylnitrosamine (DAN), one of the few nitrosamines tested thus far that has not induced neoplasms in rats, caused a high incidence of respiratory tract tumors in Syrian golden hamsters treated sc with single or weekly doses of the compound. The effect was dose-dependent. The nasal cavity, larynx, and trachea were the most affected by DAN; most drug-induced tumors at those sites were adenocarcinomas and papillary polyps.

Animals↗
PubMed1976

Transplacental effects of nitrosamines in Syrian hamsters: I. Dibutylnitrosamine and nitrosohexamethyleneimine.

The transplacental carcinogenic effects of dibutylnitrosamine (DBN) and nitrosohexamethyleneimine (N-6-MI) were examined in Syrian hamsters. A proportion of both substances reached the fetal tissue unaltered. No macroscopic malformations were observed in the offspring; however, postnatal mortality was high. Respiratory tumours were found upon histologic examination of surviving animals. Single doses of 30 mg/kg body weight (b.w.) DBN and 2 doses of 10 mg/kg b.w. N-6-MI did not induce tumours in the P-generation, but led to a low tumour incidence in the F1-generation (DBN, 7.0%, N-6-MI, 2.0%). Treatment for up to eight days during the second half of pregnancy led to a higher tumour incidence in the P-generation (DBN, 22%; N-6-MI, 20%), than in the F1-generation (DBN, 6.0%; N-6-MI, 10%).

Animals↗
PubMed1975

Carcinogenic effect of 2,2'-dimethyldipropylnitrosamine in Syrian hamsters.

Oxidation at the beta carbon occurred in metabolism of di-n-propylnitrosamine (DPN), previously shown to be carcinogenic for animals. When 2,2'-dimethyldipropylnitrosamine (DMDPN) was injected sc once a week for life into male and female Syrian hamsters at levels of 500, 250, 125, and 62.5 mg/kg body weight, it induced neoplasms in the nasal cavities, larynx, trachea, and stem bronchi. Since the presence of a methyl group on the beta carbon suggested that DMDPN could not undergo beta oxidation, the carcinogenicity of DPN for these portions of the respiratory tract was probably unrelated to beta oxidation, though earlier experiments had indicated the possibility of this mechanism. Because DMDPN failed to induce neoplasms in other organs, the carcinogenicity of DPN or its beta metabolites for the lungs, liver, pancreas, and kidneys was not explained by this experiment.

Adenocarcinoma↗
PubMed1975

Studies on liver regeneration. Deoxyribonucleic acid synthesis in the isolated perfused liver after in vitro and in vivo partial hepatectomy.

A new method for studying liver regeneration has been introduced. In the isolated perfused liver partial hepatectomy has been performed and -3H-thymidine incorporation into DNA was observed. The short term incorporation observed in vitro was comparable to that observed in vivo under similar conditions. The results suggest that similar regenerative mechanisms are operating in vivo and in vitro, and that the liver is at least one source of the regenerating stimuli.

Animals↗