Compound Toxicity Studies

Early toxicity studies may give the scientist the opportunity to determine, not only maximum tolerated doses, but also a means to identify candidate compounds that cause unacceptable effects in mayor target organs. This is important, particularly when the effects are subtle and detectable only microscopically. Such changes may also appear only at high doses but be absent at lower, therapeutic doses. To learn about such findings early in the development process can result in significant cost reductions and increase the likelyhood of approval by regulatory agencies.
A. Normal glomerulus, PAS-Methenamine Silver staining.
B. Glomerulus from compound treated animal. Note the hypercellularity and dramatic size increase as a result of treatment with this compound. This change may be subtle enough not to cause clinical or laboratory changes in the sort term but may be detrimental in the long term.
A. Liver from a control animal.
B. Liver from a treated animal. Note the presence of cholangiolar proliferation. This is a mild change that may only be observed in chronic studies.