Tracing tissues with chloroform-metabolizing capacity in rats

Rats were injected i.v. or i.p. with [14C]chloroform and the localization and binding of metabolites in the tissues were studied by whole-body and microautoradiography. Based on the autoradiographic findings various tissues were tested for their capacity to form 14CO2 and to incorporate 14C into tissue-macromolecules from the [14C]chloroform. Autoradiography in vitro was used to localize the sites of [14C]chloroform metabolism under in vitro conditions. The results of the in vitro metabolism studies showed that several tissues had a capacity to metabolize the [14C]chloroform. Further, the results showed that there was a correlation between the ability of various tissues to accumulate metabolites in the rats injected with the [14C]chloroform and the ability of the same tissues to metabolize the [14C]chloroform in vitro. The in vitro autoradiography showed an accumulation of radioactivity at sites corresponding to the ones accumulating metabolites in vivo. It is concluded that many tissues have a capacity to metabolize chloroform in vivo and in vitro. The structures identified to have a marked chloroform-metabolizing capacity were, besides the liver, the kidney cortex, the mucosa of the bronchial tree, the tracheal mucosa, the olfactory and respiratory nasal mucosa, Bowman's glands in the olfactory lamina propria mucosae, Steno's gland (the lateral nasal gland), the mucosa of the oesophagus, the larynx, the tongue, the gingiva, the cheek, the naso-pharyngeal duct, the pharynx and the soft palate (but not the hard palate).