Synthesis and disposition of 14C-labelled gentian violet in F344 rats and B6C3F1 mice.

The synthesis of [phenyl-U-14C]gentian violet from [U-14C]benzene is described. The 14C-labelled dye was administered by gavage to groups of male and female F344 rats which were killed at 2, 4, 14, 24 or 36 hr after the single dose. Radioactivity was measured in urine, and determined in faeces, liver, kidney, fatty tissue, gonads and muscle by combustion analysis. Residues were maximal at 4 hr in liver, kidney, muscle and gonads, and in fat they reached a plateau after 24 hr. Depletion half-lives for male and female livers were 14.5 and 17.0 hr, respectively. The 14C-labelled dye was also administered in multiple doses by gavage to both sexes of F344 rats and B6C3F1 hybrid mice for 7 days. The highest residue level was found in fatty tissue of females of both species, with a highly significant sex difference (P less than 0.01). Significant sex differences were also noted for residue levels in kidney and muscle tissue from both species and in mouse liver. Bile collected from cannulated rats contained 5.7-6.4% of a single oral dose of the dye. The results suggest that gentian violet is absorbed from the gastro-intestinal tract to a greater extent than has been reported for other triphenylmethane dyes.

Strain differences in the response of the mouse to diethylstilbestrol.

BALB/c StCrlfC3Hf/Nctr, C57BL/6/, C57BL/6 X BALB/c F1 hybrid (B6CF1), and monohybrid-cross offspring from the breeding of B6CF1 mice were examined with respect to uterine, vaginal, and thymus responses to diethylstilbestrol (DES). About 400 mice of each genetic population were used. Weanling mice were fed DES at dietary concentrations of 2.5 to 1,000 ppb (microgram/kg feed) for 6 days and were killed by cervical dislocation about 20 hr after removal of the feed. C57BL/6, B6CF1, and the monohybrid-cross offspring did not differ in the uterine-weight response to DES, but the slope of the dose-response line was shallower for the BALB/c than for the other strains. Dietary DES concentrations of 250 ppb or more inhibited the uterotrophic response in all populations. Vaginal cornification occurred at lower concentrations of DES in the C57BL/6 strain than in the B6CF1 animals. BALB/c and monohybrid-cross offspring were indistinguishable from each other in their vaginal response to Des and were less sensitive to DES than the other mouse populations. The use of ethanol or corn oil as the solvent for mixing DES into the diet had no apparent effect on the uterine weight or vaginal response in any of the mice. DES depressed thymus weight in a dose-related fashion at dietary concentrations of 100 ppb and above in all genetic populations.

Mast cell neoplasia in mice.

Gross and histopathologic findings were reported for mast cell neoplasia in 2 female BALB/cStCrIBR mice. Microscopic findings included neoplastic mast cells in the liver, spleen, kidney and lymph nodes. Neoplastic mast cells were present in the blood smear of one of the animals.