Premium
Effects of fungicides on thyroid function, metabolism, and thermoregulation in cotton rats
Author(s) -
Tomasi Thomas E.,
Ashcraft John,
Britzke Eric
Publication year - 2001
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620200813
Subject(s) - endocrinology , medicine , thyroid , mancozeb , thermoregulation , thyroid function , vinclozolin , thermogenesis , hormone , metabolism , biology , homeothermy , basal metabolic rate , metabolic rate , endocrine system , chemistry , fungicide , adipose tissue , botany
Among the myriad of recent studies on endocrine‐disrupting chemicals, relatively few involve thyroid disruption, and most of these address exposure/disruption during embryonic life. Of those involving adult vertebrates, the endpoints examined are thyroid measurements. Even though thyroid disruption could potentially interfere with energy metabolism and thermoregulation such that over‐winter survival might be compromised, the possible energetic consequences of these thyroid perturbations have not been investigated. We assessed thyroid function and measured resting metabolic rates of cotton rats chronically exposed to the fungicides vinclozolin or mancozeb. In addition, we measured norepinephrine‐induced nonshivering thermogenesis and cold‐induced thermogenesis and then cold‐acclimated the mancozeb animals. Although thyroid hormone concentrations generally decreased, this was compensated for by an increase in thyroxine turnover (vinclozolin study only) such that thyroxine utilization rate was not different. In addition, there was no difference between the treated and control animals in any of the metabolic parameters measured. It is concluded that wild rodents exposed to these compounds are not energetically compromised.