Research Pharmacologist — Division of Biochemical Toxicology
Kenneth Barry Delclos, Ph.D.
Kenneth Barry Delclos received a Bachelor of Arts degree in biological sciences from Cornell University and a Ph.D. in pharmacology from Harvard University. He carried out postdoctoral work in the Department of Oncology at the McArdle Laboratory for Cancer Research at the University of Wisconsin and has since been in his current position at NCTR. His earlier research efforts focused primarily on chemical carcinogenesis while more recently his focus has been on toxicities associated with endocrine active agents and, to a lesser extent, the dietary modulation of toxicity.
There has been much interest and controversy in recent years concerning the potential health effects of chemical agents that affect hormone signaling, so-called “endocrine disrupters.” Dr. Delclos’s laboratory has been involved in studies with several hormonally active compounds to assess their reproductive toxicity and carcinogenic activity across generations and to assess the impact of developmental exposure. An example is a major effort to address regulatory issues on the toxicity of Bisphenol A (BPA), a compound FDA regulates primarily in food-contact materials. Studies were designed to address data gaps and address deficiencies in study designs in many of the existing studies and a two-year study included participation from a large group of academic investigators, many of whom are critical of the current FDA safety assessment of BPA. Results from these studies are informing safety assessments of BPA in the U.S and internationally. Results of the studies of endocrine disrupters have also indicated the ability of dietary components to modulate or induce toxic responses. For example, suboptimal levels of thiamine in a mouse diet, that is, a low level not associated with any of the clinical signs of thiamine deficiency, impaired spermatogenesis. Also, an oral bolus of lipid administered to neonatal rats disrupted spermatogenesis, apparently through a gut hormone-mediated mechanism. These observations may warrant further investigation as to their relevance in humans. Future plans for the laboratory include investigation of the reproductive toxicity of oral antidiabetic agents that are increasingly used off-label to treat gestational diabetes mellitus despite unknown long-term effects on offspring.
Professional Societies/National and International Groups
Federal Insecticide, Fungicide, and Rodenticide Scientific Advisory Panel, Environmental Protection Agency (EPA)
Permanent Panel Member
2012 – 2015
2016 – Present
Food and Chemical Toxicology
2016 – Present
Society of Toxicology
2012 – Present
Effects of Intravenous and Oral Di(2-Ethylhexyl) Phthalate (DEHP) and 20% Intralipid Vehicle on Neonatal Rat Testis, Lung, Liver, and Kidney.
Camacho L., Latendresse J., Muskhelishvili L., Law C.D., and Delclos K.B.
Food Chem Toxicol, 2020,12:111497 (ahead of print).
A Two-Year Toxicology Study of Bisphenol A (BPA) in Sprague-Dawley Rats: CLARITY-BPA Core Study Results.
Camacho L., Lewis S.M., Vanlandingham M.M., Olson G.R., Davis K.J., Patton R.E., Twaddle N.C., Doerge D.R., Churchwell M.I., Bryant M.S., McLellen F.M., Woodling K.A., Felton R.P., Maisha M.P., Juliar B.E., Gamboa da Costa G., and Delclos K.B.
Food Chem Toxicol, 2019, 132:110728.
NTP Research Report on the CLARITY-BPA Core Study: A Perinatal and Chronic Extended-Dose-Range Study of Bisphenol A in Rats.
National Toxicology Program
National Toxicology Program Research Report 9, 2018.
Advancing Human Health Risk Assessment.
Lanzoni A., Castoldi A., Kass G., Terron A., De Seze G., Bal-Prince A., Bois F., Delclos K., Doerge D., Fritsche E., Halldorsson T., Kolossa-Gehring M., Hougaard Bennekou S., Koning F., Lampen A., Leist M., Mantus E., Rousselle C., Siegrist M., Steinberg P., Tritscher A., Van de Water B., Vineis P., Walker N., Wallace H., Whelan M, and Younes M.
EFSA J. 2019, 17 (Suppl 1): e170712.
Comparison of Endpoints Relevant to Toxicity Assessments in 3 Generations of CD-1 Mice Fed Irradiated and Natural and Purified Ingredient Diets with Varying Soy Protein and Isoflavone Contents.
Camacho L., Lewis S., Vanlandingham M., Juliar B., Olson G., Patton R., Gamboa da Costa G., Woodling K., Sepehr E., Bryant M., Doerge D., Basavarajappa M., Felton R., and Delclos K.
Food Chem Toxicol. 2016, 94: 39-56.
NIEHS/FDA CLARITY-BPA Update.
Heindel J., Newblod R., Bucher J., Camacho L., Delclos K., Lewis S., Vanlandingham M., Churchwell M., Twaddle N., McLellen M., Chidambaram M., Bryant M., Woodling K., Gamboa da Costa G., Ferguson S., Flaws J., Howard P., Walker N., Zoeller R., Fostel J., Favaro C., and Schug T.
Reprod Toxicol. 2015, 58: 33-44.
Effects of Oral Exposure to Bisphenol A on Gene Expression and Global Genomic DNA Methylation in Prostate, Female Mammary Gland, and Uterus of NCTR Sprague-Dawley Rats.
Camacho L., Basavarajappa M., Chang C., Han T., Kobets T., Koturbash I., Surratt G., Lewis S., Vanlandingham M., Gamboa da Costa G., Porgribny I., and Delclos K.
Food Chem Toxicol. 2015, 81: 92-103.
Investigation of the Effects of Subchronic Low Dose Oral Exposure to Bisphenol A (BPA) and Ethinyl Estradiol (EE) on Estrogen Receptor Expression in the Juvenile and Adult Female Rat Hypothalamus.
Rebuli M., Cao J., Sluzas E., Delclos K., Camacho L., Lewis S., Vanlandingham M., and Patisaul H.
Toxicol Sci. 2014, 140: 190-203.
Toxicity Evaluation of Bisphenol A Administered by Gavage to Sprague-Dawley Rats from Gestation Day 6 Through Postnatal Day 90.
Delclos K., Camacho L., Lewis S., Vanlandingham M., Latendresse J., Olson G., Davis K., Patton R., Gamboa da Costa G., Woodling K., Bryant M., Chidambaram M., Trbojevich R., Juliar B., Felton R., and Thorn B.
Toxicol Sci. 2014, 139: 174-197.
Comparison of Life-Stage-Dependent Internal Dosimetry for Bisphenol A, Ethinyl Estradiol, a Reference Estrogen, and Endogenous Estradiol to Test an Estrogenic Mode of Action in Sprague Dawley Rats.
Churchwell M., Camacho L., Vanlandingham M., Twaddle N., Sepehr E., Delclos K., Fisher J., and Doerge D.
Toxicol Sci. 2014, 139: 4-20.
A New Approach to Synergize Academic and Regulatory-Compliant Research: The CLARITY-BPA Research Program.
Schug T., Heindel J., Camacho L., Delclos K., Howard P., Johnson A., Aungst J., Keefe D., Newbold R., Walker N., Zoeller T., and Bucher J.
Reprod Toxicol. 2013, 40: 35-40.
Lactational Transfer of Bisphenol A in Sprague-Dawley Rats.
Doerge D., Vanlandingham M., Twaddle N., and Delclos K.
Toxicol Lett. 2010, 199: 372-376.
Genistein and Ethinyl Estradiol Dietary Exposure in Multigenerational and Chronic Studies Induce Similar Proliferative Lesions in Mammary Gland of Male Sprague-Dawley Rats.
Latendresse J., Bucci T., Olson G., Mellick P., Weis C., Thorn B., Newbold R., and Delclos K.
Reprod Toxicol. 2009, 28: 342-353.
Overlapping but Distinct Effects of Genistein and Ethinyl Estradiol (EE2) in Female Sprague-Dawley Rats in Multigenerational Reproductive and Chronic Toxicity Studies.
Delclos K., Weis C., Bucci T., Olson G., Mellick P., Sadovova N., Latendresse J., Thorn B., and Newbold R.
Reprod Toxicol. 2009, 27: 117-132.
Few Effects of Multi-Generational Dietary Exposure to Genistein or Nonylphenol on Sodium Solution in Male and Female Sprague-Dawley Rats.
Ferguson S., Delclos K., Newbold R., and Flynn K.
Neurotoxicol Teratol. 2009, 31: 143-148.
Multigenerational Exposure to Ethinyl Estradiol Affects Bone Geometry, but Not Bone Mineral Density in Rats.
Hotchkiss C., Weis C., Blaydes B., Newbold R., and Delclos K.
Bone. 2008, 43: 110-118.
Dietary Modulation of P-Nonylphenol-Induced Polycystic Kidneys in Male Sprague-Dawley Rats.
Cooper S., Latendresse J., Doerge D., Twaddle N., Fu X., and Delclos K.
Toxicol Sci. 2006, 91: 631-642.
Lactational Transfer of the Soy Isoflavone, Genistein, in Sprague-Dawley Rats Consuming Dietary Genistein.
Doerge D., Twaddle N., Churchwell M., Newbold R., and Delclos K.
Reprod Toxicol. 2006, 21: 307-312.
- Contact Information
- Kenneth Barry Delclos
- (870) 543-7121
ExpertiseApproachDomainTechnology & DisciplineToxicology