ID#

761

Location:

Exhibit Hall

Time of Presentation:

March 11, 2003 - 9:30 a.m.

Category (Subcategory):

In Vitro/Alternative Animal Models, (Safety Evaluation)

Design of a Validation Study to Evaluate In Vitro Cytotoxicity Assays for Predicting Rodent and Human Acute Systemic Toxicity
J.A. Strickland^1,2; W.S. Stokes²; S. Casati³; M.W. Paris^1,2; A.P. Worth³; H. Raabe⁴; C. Cao⁵; R. Clothier⁶; J. Harbell⁴; R. Curren⁴;
J. Haseman⁷; R.R. Tice^1,2
1. ILS, Inc., RTP, NC, USA;
2. NICEATM, NIEHS, RTP, NC, USA;
3. JRC, ECVAM, Ispra, IT;
4. IIVS, Inc., Gaithersburg, MD, USA;
5. Edgewood Chemical Biological Center, US Army, APG, MD, USA;
6. Univ. of Nottingham, Nottingham, UK;
7. NIEHS, RTP, NC, USA;

An international expert workshop convened by the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) and NICEATM in October 2000 recommended that two in vitro basal cytotoxicity methods should be further evaluated to determine their usefulness for predicting rodent and human acute toxicity. NICEATM and ECVAM subsequently designed and initiated a multi-laboratory validation study to evaluate the relevance and reproducibility of two neutral red uptake assays using a mouse 3T3 fibroblast cell line and normal human epidermal keratinocytes. Seventy-two coded chemicals provided from a central repository and representing 12 chemicals from each of six hazard classification categories will be tested three times in each of three laboratories. The study is proceeding in three phases. Phase Ia established the historical databases for the positive control (sodium laurel sulfate) for each laboratory. The protocol will then be optimized to further minimize intra- and inter-laboratory variation after testing 3 chemicals in Phases Ib and 9 chemicals in Phase II. Sixty chemicals will then be tested in Phase III. The Registry of Cytotoxicity prediction model will be used to evaluate the prediction of rodent oral LD50 tests. Prediction of human toxicity will be evaluated using a prediction model based on human poisoning data. This study will characterize the usefulness of these cytotoxicity tests for predicting acute systemic toxicity and the extent that they may reduce or replace animal use. Supported by NIEHS contract N01-ES-85424 and EPA IAG DW-75-93893601-0.