Effect of route of administration in the micronucleus test with potassium bromate

The effect of intraperitoneal injection (i.p.) versus oral gavage administration (p.o.) of potassium bromate was examined using the micronucleus test in 2 strains of male mice (MS/Ae and CD-1). First, a small acute toxicity test and a pilot micronucleus experiment were performed to determine the appropriate dose range and sampling time for the full-scale micronucleus test. The full-scale test was carried out using doses of 18.8, 37.5, 75, and 150 mg/kg in the i.p. test and of 37.5, 75, 150, and 300 mg/kg in the p.o. test. The sampling time was 24 h for both mouse strains. Potassium bromate induced micronucleated polychromatic erythrocytes (MNPCEs) dose-dependently by both routes of administration in both mouse strains. No distinct difference in route of administration was observed in the test with MS/Ae mice. In CD-1 mice more MNPCEs were induced by the i.p. route than by the p.o. route.     

A pituitary-salivary mixed gland induced by tissue recombination of embryonic pituitary epithelium and embryonic submandibular gland mesenchyme in mice

Renal subcapsular syngrafts of Day 9 to 11 mouse embryonic pituitary epithelium with Day 14 mouse embryonic submandibular gland mesenchyme produced mixed organs that include residual cleft structure surrounded by anterior pituitary cells some which are stained by anti-ACTH antiserum and submandibular gland-like structure with differentiated acinar cells which are stained by anti-alpha-amylase antiserum. However, when Day 8.5 or 12 embryonic pituitary epithelium was recombined with submandibular gland mesenchyme and syngrafted, development of submandibular gland-like or anterior pituitary tissues resulted, respectively. Thus, during organogenesis of the mouse anterior pituitary, there exists a developmental stage (Day 8.5-11 in utero), when prospective pituitary epithelium can respond to heterotypic submandibular gland mesenchyme with the development of a submandibular gland-like tissue.     

Isolation of furanoterpene-containing particles from Ceratocystis fimbriata-infected sweet potato root tissue

Furanoterpene-containing particles were isolated by centrifugation on a discontinuous Ficoll density gradient from a homogenate of the non-infected tissue adjacent to the infected region of Ceratocystis fimbriata-infected sweet potato root tissue. The particles were recovered at a relatively high ratio in the 2% Ficoll fraction, in which there was no contamination by mitochondria and only little by endoplasmic reticulum judging from the distribution of the activities of their marker enzymes and electron micrographs. Each particle was enveloped in a single membrane, 7-10 nm thick.