Whole-body autoradiographic study on the distribution of 3H-cryptolepine in mice.

The distribution of 3H-cryptolepine in pigmented and albino mice and in pregnant mice on day 16 of gestation was studied by whole-body autoradiography, after a single intravenous injection. The labelled compound rapidly left the blood and was localized in most tissues, except for the central nervous system where no radioactivity could be observed. The most pronounced decrease of concentration occurred between 1 and 4 hours postinjection.

Differential distribution and placental transport of 2- and 3-t-[methyl-14C]butyl-4-hydroxyanisole (BHA) in pregnant mice.

The placental transport and localization in fetal and maternal tissues of 14C-BHA isomers, 2-t-[methyl-14C]butyl-4-hydroxyanisole (2-BHA) and 3-t-[methyl-14C]butyl-4-hydroxyanisole (3-BHA), were studied in pregnant mice by whole-body autoradiography techniques. BHA isomers were given (iv 50 microCi/100 g as a tracer dose) to pregnant mice at Day 11 (organogenesis) and Day 18 (postorganogenesis) of gestation. Peak levels of radioactivity occurred in various tissues 1-4 hr after iv administration of both isomers.

Computer-assisted quantification and image processing of whole-body autoradiograms.

A computerized image-processing system especially adapted for analysis of whole-body autoradiograms has been developed. It consists of commercially available standard components, including a black-and-white video camera, a microcomputer, and graphics equipment. The lower performance of the hardware has been compensated for by more flexible software.

Selective incorporation of thiouracil into murine metastatic melanomas.

The uptake and retention of 14C-thiouracil and 125I-thiouracil in small lung metastases of B16 murine melanoma was studied in beige mice injected intravenously with melanoma cells. By impulse counting of excised tumor and organ pieces, a high concentration of radioactivity was found in the lung metastases, as compared to normal tissues. The highest tumor/organ concentration ratios appeared 24 h after injection of the radiolabeled thiouracil.

Rate of incorporation of [3H]thymidine in various tissues of the mouse. A basis for the evaluation of genotoxic effects of chemicals.

[3H]Thymidine has been extensively used as a selective precursor to DNA in studies on the kinetics of cell proliferation. We have become interested in measuring early inhibition of the DNA synthesis in various organs of intact animals for detecting genotoxic properties of chemicals. Such experiments should, for convenience and to achieve a large capacity, be performed in the simplest way possible.