Introduction of gloved hand to cage induces 22-kHz ultrasonic vocalizations in male albino rats.

Rodents emit ultrasonic vocalizations (USVs) above the human hearing threshold of ~ 20 kHz to communicate emotional states and to coordinate their social interactive behavior. Twenty-two kHz USVs emitted by adult rats have been reported in a variety of aversive social and behavioral situations. They occur not only under painful or restraining conditions but can also be evoked by gentle cutaneous touch or airflow.

Lens cholesterol biosynthesis inhibition: A common mechanism of cataract formation in laboratory animals by pharmaceutical products.

CJ-12,918, a 5-lipoxygenase (5-LO) inhibitor, caused cataracts during a 1-month safety assessment studies in rats whereas the structurally similar ZD-2138 was without effect. For CJ-12,918 analogs, blocking different sites of metabolic liability reduced (CJ-13,454) and eliminated (CJ-13,610) cataract formation in both rats and dogs. Using this chemical series as a test set, models and mechanisms of toxicity were first explored by testing the utility of ex vivo rat lens explant cultures as a safety screen.

Assessment of endogenous 25-hydroxyvitamin D serum concentrations by liquid chromatography-tandem mass spectrometry in various animal species.

Background: Mass spectrometry (MS) has become the preferential method for the analysis of vitamin D in the clinic, yet no single platform is utilized for preclinical species in drug development studies. For vitamin D, the MS platform can provide certain benefits such as applicability of a single assay for multiple species, low cost, and high specificity.

Objectives: A quantitative liquid chromatography-tandem MS (LC-MS/MS) assay for 25-hydroxyvitamin D (25OHD ) and D (25OHD ) was validated for rat, dog, mouse, and monkey, and suitability for drug development studies was assessed.

Ciglitazone-induced lenticular opacities in rats: in vivo and whole lens explant culture evaluation.

The cataractogenic potential of the thiazolidinedione ciglitazone (CIG) was investigated in vivo and in vitro. In the rat, CIG caused a dose-dependent (30-300 mg/kg/day) increase in incidence and severity of nuclear cataract formation during a 3-month nonclinical safety assessment study. Potential mechanisms of toxicity were surveyed using whole rat lens explants exposed to CIG with or without various inhibitors of cataract formation.