Gender-specific effects of thyroid hormones on cardiopulmonary function in SHHF rats.
Spontaneously hypertensive heart failure (SHHF) rats develop hypertension and heart failure. We hypothesized that induction of hyperthyroidism should accelerate development of heart failure in male SHHF rats. Male and female SHHF rats received diets containing desiccated thyroid glands (DTG) or a control diet for 8 wk. Male and female Wistar-Kyoto rats were used as normotensive controls. DTG treatment reduced body weight in male, but not female, SHHF rats but increased body temperature and heart weight-to-body weight ratio in both genders. In DTG-treated male SHHF rats, serum triiodothyronine levels doubled relative to SHHF controls, whereas O2 consumption increased in DTG-treated SHHF rats. Frequency of breathing in air increased in DTG-treated female rats, and ventilation increased in DTG-treated male rats. Ventilatory equivalents exhibited gender differences in SHHF rats, were decreased in both genders by DTG treatment, and reached levels similar to those of Wistar-Kyoto rats. DTG increased heart rate, right ventricular pressure, and contractility in both genders and increased left ventricular pressure in SHHF male rats. These results refute our hypothesis and suggest that cardiopulmonary function of SHHF male rats may be improved by DTG treatment.
Schlenker
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Division of Basic Biomedical Sciences, University of South Dakota School of Medicine, Vermillion, SD 57069, USA. eschlenk@usd.edu
Tamura
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Gerdes
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D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D005260:Female; D006321:Heart / Q000187:drug effects*; D006333:Heart Failure / Q000235:genetics; D006439:Hemodynamics / Q000187:drug effects; D008168:Lung / Q000187:drug effects*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012129:Respiratory Function Tests; D012727:Sex Characteristics; D013963:Thyroid Hormones / Q000097:blood / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects; D016278:Ventricular Function, Right / Q000187:drug effects
D013963:Thyroid Hormones