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9516684 
Journal Article 
A comparative study on the effects of thiourea and large doses of radioiodine on the thyroid and thyrotrophs of Mystus vittatus (bloch) 
Srivastava, SS; Sathvanesan, AG 
1971 
Yes 
Cells Tissues Organs
ISSN: 1422-6405
EISSN: 1422-6421 
79 
4 
556-569 
English 
The thyroid of M. vittatus examined 15 days after injecting a heavy dose of I-131, well defined histological changes were noticed. Initially, hypertrophy and hyperplasia of the follicular epithelium and hyperemia of the thyroid area were noticed, later accompanied by degenerative changes characterised by follicular atrophy, nuclear necrosis, edema and perifollicular fibrosis. By the end of the first month and early in the second month only a few microfollicles and degenerating follicular debris were noticed in the fibrosed thyroid region. After ninety days there were no histological signs of any thyroid tissue. In one specimen, eight months after one mCi treatment several cystic tumours were seen in the thyroid region; some of which exhibited proliferation and an invasive tendency. The thyrotrophs arc distributed in the proximal pars distalis. They are stainable with PAS. AF and aniline blue. During the first fortnight of I-131 treatment they showed signs of stimulation characterised by hypertrophy, degranulation and vacuolisation. However, later they were completely degranulated and rendered chromophobic. In one specimen PAS-positive cystic bodies were seen in the proximal pars distalis eleven months after radioiodine treatment. Thyroid response to thiourea in M. vittatus was found to be slow. Obvious histological changes were noticed only twelve weeks after immersion. During the 20th week maximum hypertrophy, hyperplasia and hyperemia were evident. However, no signs of degeneration or tumorigenic tendency were seen during the experimental period. The stimulatory response of thyrotrophs in specimens subjected to thiourea was comparable to the 15 days post I-131 treated ones. © 1971 S. Karger AG, Basel.