03-3913. National Toxicology Program; Center for the Evaluation of Risks to Human Reproduction: Notice of a Workshop on Thyroid Hormones and Reproduction

Summary

The Center for the Evaluation of Risks to Human Reproduction (CERHR) is sponsoring a workshop entitled “Thyroid Toxicants: Assessing Reproductive Health Effects” on April 28 and 29, 2003 at the Holiday Inn Old Town Select Hotel, 480 King Street, Alexandria, VA 22314 (telephone: [phone], fax: [phone]). Registration begins at 8:30 am on April 28 and the meeting begins at 9 am each day. This meeting is open to the public with attendance limited only by the availability of space. Persons interested in attending are requested to pre-register for this meeting by contacting CERHR (contact information below). A preliminary agenda is provided below and additional meeting information will be posted, as available, on the CERHR Web site: http://cerhr.niehs.nih.gov.

Background

Thyroid function is modulated through physiological feedback mechanisms. Hypothyroid and hyperthyroid states are well known in humans with some being associated with iodine levels in the environment. Some drugs are known to enhance or repress thyroid function, and a recent article identified 116 synthetic chemicals that “interfere” with production, transport, or metabolism of thyroid hormone. Thyroid hormone levels modulate other hormone-producing tissues particularly those that involve reproduction, development, or mental performance. Both hypothyroidism and hyperthyroidism are reported to be associated with an increased risk of adverse pregnancy outcomes in humans.

The purpose of this NTP-CERHR workshop is two-fold:

(1) To discuss and determine appropriate designs of developmental and reproductive toxicity tests for detecting adverse effects resulting from thyroid dysfunction.

(2) To discuss the relevance of thyroid-related adverse reproductive and developmental effects observed in rodents for predicting similar effects in humans.

Preliminary Meeting Agenda

Thyroid Toxicants: Assessing Reproductive Health Effects, Holiday Inn Old Town Select Hotel, 480 King Street, Alexandria, VA 22314 (telephone: [phone]).

Day 1—Monday, April 28

8:30 a.m. Registration

9 Introduction

Summary of thyroid conference, “Thyroid Hormone and Brain Development: Translating Molecular Mechanisms to Population Risk,” held at the National Institute of Environmental Health Sciences on September 23-25, 2002

A review of current alternative assays for assessing thyroid toxicity

Session 1: A comparison of normal thyroid development/control/function in rodents and humans

10:45 Break

Session 2: Comparison of the reproductive and developmental effects of hypo/hyperthyroidism in rodents and humans

Discussion

Noon Lunch (on your own)

1 p.m. Session 2, continued: Human/rodent comparison of reproductive effects of selected thyroid active chemicals

Methimazole

PTU

Phenobarbital

Sulfamethazine

Discussion

5 Adjourn

Day 2—Tuesday, April 29

9 a.m.

Session 3: The elements of a rodent testing protocol to consider in assessing thyroid effects on reproduction and development and their relevance to human health effects

Discussion

10:15 Break

Session 4: An overview of 1) appropriate rodent protocols for detecting thyroid effects on reproduction and development and 2) the appropriate use of rodent data for predicting human effects

Discussion

Noon Adjourn

As additional details and materials for this workshop become available, they will be posted on the CERHR Web site (http://cerhr.niehs.nih.gov) or can be obtained by contacting Dr. Michael Shelby, Director, CERHR, NIEHS, P.O. Box 12233, MD EC-32, Research Triangle Park, NC 27709; telephone: [phone]; fax: [phone]; e-mail: [e-mail]

Pre-Registration

This workshop is open to the public and interested individuals are encouraged to attend. Time is set aside for open discussion throughout the meeting to provide an opportunity for all attendees to contribute to the scientific discussion. The number of attendees will be limited only by the space available. Due to the limitations of space, pre-registration for this meeting is encouraged. To pre-register, please provide your name, affiliation, contact information and email address by Friday, April 18, 2003, to: Ms. Harriet McCollum, CERHR, Suite 500, 1800 Diagonal Road, Alexandria, VA 22314; telephone: [phone]; fax: [phone]; email: [e-mail]

Dated: February 7, 2003.

Samuel H. Wilson,

Deputy Director, National Institute of Environmental Health Sciences.