Testosterone and estradiol treatments differently affect pituitary-thyroid axis and liver deiodinase 1 activity in orchidectomized middle-aged rats
2015
Аутори:
Šošić-Jurjević, BrankaFilipović, Branko
Renko, Kostja
Miler, Marko
Trifunović, Svetlana
Ajdžanović, Vladimir
Koehrle, Josef
Milošević, Verica
Тип документа:
Чланак у часопису (Објављена верзија)
,
© 2015 Elsevier Inc.
Метаподаци
Приказ свих података о документуАпстракт:
We previously reported that orchidectomy (Orx) of middle-aged rats
(15-16-month-old; MA) slightly affected pituitary-thyroid axis, but
decreased liver deiodinase (Dio) type I and pituitary Dio2 enzyme
activities. At present, we examined the effects of subsequent
testosterone-propionate treatment (5 mg/kg; Orx + T), and compared the
effects of testosterone with the effects of estradiol-clipropionate
(0.06 mg/kg; Orx + E) treatment. Hormones were subcutaneously
administered, daily, for three weeks, while Orx and sham-operated (SO)
controls received only the vehicle. The applied dose of T did not alter
serum TSH, T4 and T3 concentrations in Orx- MA, though it increased TSH
when administrated to Orx young adults (2.5-month-old; Orx-YA). However,
pituitaries of Orx-MA + T rats had higher relative intensity of
immunofluorescence (RIP) for TSHI3; in their thyroids we found increased
volume and height of follicular epithelium, decreased volume of the
colloid and higher RIF for T,{[}-bound to thyroglobulin (Tg-T4). Liver
Diol activity was increased. E-treatment did not affect serum hormone
levels, pituitary RIF for TS1-11i, or liver Diol activity in Orx-MA
rats. Thyroids had decreased relative volume and height of follicular
epithelium, increased relative volume of the colloid, decreased volume
of sodium iodide symporter-immunopositive epithelium and lower RIF for
Tg-T4. Detected changes were statistically significant. In conclusion,
androgenization enhanced pituitary TSHr, RIF, thyroid activation and
liver Diol enzyme activity in Orx-MA, without elevating serum TSH as in
Orx-YA rats. Estrogenization induced pituitary enlargement with no
effect on pituitary TSHI) RIF, serum TSH or liver Diol activity. E also
induced alterations in thyroid histology that indicate mild suppression
of its functioning, and contributed to thyroid blood vessel enlargement
in Orx-MA rats. (C) 2015 Elsevier Inc. All rights reserved.
Кључне речи:
Testosterone; Estracliol; Pituitary-thyroid axis; Middle age; RatИзвор:
Experimental Gerontology, 2015, 72, 85-98
DOI: 10.1016/j.exger.2015.09.010
ISSN: 0531-5565