Irv Schultz, Ph.D.
Expertise
Dr. Irv Schultz has been involved in toxicological research since 1986, with broad interests covering both ecological and human health issues. Highlights of previous research efforts include studies on the metabolism and disposition of environmental pollutants in fish, with an emphasis on allometric and interspecies scaling; FDA-sponsored drug registration studies for the aquaculture industry, and the disposition and bioavailablity of inorganic and organo-metallic compounds in fish. For many years, Dr. Schultz has studied the disposition of drinking water disinfection byproducts (which are suspected human carcinogens) in human volunteers, non-human primates, and rodent animal models. Dr. Schultz led the original DOE-funded research to assess the impact of endocrine-disrupting chemicals through the use of an in-vivo model using rainbow trout. For this program, a physiologically based toxicokinetic toxicodynamic model (PBTK) was developed to describe the chemical dosimetry and estrogenic activity of xenobiotics as reflected by induction of the biomarker protein Vitellogenin (Vg). This model can be used to predict the "estrogenicity" of equivalent estrogen doses based on the extent of Vg induction, which can then be applied to both ecological and human risk assessments. A significant discovery was the finding that environmental levels of xeno-estrogens reduce the fertility of male trout. The initial research formed the foundation to the current $34 M U.S. Environmental Protection Agency (EPA) research program to study endocrine disrupting effects in the environment. Dr. Schultz is the lead author on several Detailed Review Papers, which is the first step in the development of standardized protocols for reproductive screening assays to assess the effects of contaminants in several species of fish. Other aspects of the study will involve prevalidation and comparative studies, resulting in an EPA-certified protocol for screening and testing chemicals that have the potential to have endocrine disruptive effects in both animals and humans. Dr. Schultz’s laboratory is also developing computational models of the brain-pituitary-gonadal axis in fish, which are being used to link quantitative indices of sublethal toxicity, such as reduced fertility, with changes in the endocrine system and subsequent unnatural gene and protein expression. He is using DNA microarrays to determine changes in gene expression following exposure to endocrine disruptor compounds.
Education
- Ph.D., Washington State University, Pharmacology/Toxicology, 1990
- B.S., Oregon State University, Fisheries Biology, 1986
Professional Affiliations
- Member, Society of Environmental Toxicology and Chemistry
- Associate Member, Society of Toxicology
Selected Publications
Saghir SA, and IR Schultz. 2005. "Toxicokinetics and Oral Bioavailability of Halogenated Acetic Acids Mixtures in Naive and GSTzeta-Depleted Rats." Toxicological Sciences 84(2):214-224.
Wunschel DS, IR Schultz, AD Skillman, and KL Wahl. 2005. "Method for Detection and Quantitation of Fathead Minnow Vitellogenin (Vtg) by Liquid Chromatography and Matrix Assisted Laser Desorption/ Ionization Mass Spectrometry ." Aquatic Toxicology 73:256-267.
Keys DA, IR Schultz, DA Mahle, and JW Fisher. 2004. "A Quantitative Description of Suicide Inhibition of Dichloroacetic Acid in Rats and Mice." Toxicological Sciences 82(2):381-393.
Schultz IR, AD Skillman, J Nicolas, DG Cyr, and JJ Nagler. 2003. "Short-term exposure to 17alpha-ethynylestradiol decreases the fertility of sexually maturing male rainbow trout (Oncorhynchus mykiss)." Environmental Toxicology and Chemistry 22(6):1272-1280.
Saghir SA, and IR Schultz. 2002. "Low-Dose Pharmacokinetics and Oral Bioavailability of Dichloroacetate in Naive and GST-zeta Depleted Rats." Environmental Health Perspectives 110(8):757-763.