Development of a new opacitometer for the bovine corneal opacity and permeability (BCOP) assay.

The bovine corneal opacity and permeability (BCOP) assay is an in vitro eye irritation test that relies on the measurement of induced opacity and permeability evaluated in isolated bovine corneas. Routinely, opacity is measured by an OP-KIT opacitometer which provides a centre-weighted reading of light transmission through the corneal tissue. However, this may underestimate opacity that develops as spots or heterogeneous opaque areas on the periphery of isolated cornea.

Evaluation of the HET-CAM-TSA method as an alternative to the draize eye irritation test.

The Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) method was modified in our laboratory by means of microscopic evaluation, a clear description of the three in vitro endpoints (haemorrhage, lysis and coagulation) and the use of a test substance applicator (TSA). A previous study on 46 chemicals demonstrated the usage of the HET-CAM-TSA assay as a screening test for eye irritancy. In order to extend our database and to come to a more reliable conclusion concerning the use of the HET-CAM-TSA method, a second set of 60 test substances was tested.

Evaluation of a modified HET-CAM assay as a screening test for eye irritancy.

The hen's egg test-chorioallantoic membrane (HET-CAM) assay, an alternative to the Draize eye irritation test, was developed by Luepke and has been improved on by means of a microscopic examination and the use of a test substance applicator (TSA). The TSA is a double teflon ring in which a perlon mesh is locked, and has several advantages over conventional protocols, reducing subjectivity of the method and avoiding the need for rinsing after treatment. It was confirmed by statistical analysis that the HET-CAM-TSA method can reproduce potentialin vivo irritant effects on the conjunctiva.

Evaluation of the bovine corneal opacity-permeability assay as an in vitro alternative to the Draize eye irritation test.

The bovine corneal opacity-permeability assay (BCO-P) was evaluated as an in vitro alternative test model for the Draize eye irritancy test. Fifty pharmaceutical and commercially available compounds were tested in the BCO-P assay. The compounds were selected on the basis of their in vivo irritancy potential as determined in previous Draize tests.

Sampling times in micronucleus testing.

A series of micronucleus inducers were evaluated in the mouse bone marrow micronucleus test to determine if a 72-h sampling time enhances the sensitivity for detecting genotoxic agents. Male and female Swiss albino mice were dosed once with 7,12- dimethylbenz[a]anthracene, 6-mercaptopurine, benzo[a]pyrene, benzene, cyclophosphamide, 2-acetylaminofluorene, tubulazole, or mitomycin C. According to the EEC and OECD guidelines, the mice were killed at 24, 48 and 72 h after dosing.