The thyroid C cells of ovariectomized rats treated with estradiol.
The structure and function of thyroid C cells were studied in ovariectomized (Ovx) adult female rats without and after chronic treatment with estradiol dipropionate (EDP). A peroxidase-antiperoxidase method was applied for localization of calcitonin (CT) in the C cells. Morphometric changes in their volume, nuclei, and relative volume density were evaluated in comparison with sham-operated control rats using a stereological method. The number of C cells was calculated. CT content in the sera was determined by radioimmunoassay. Ovariectomy (Ovx) led to a 21% increase in body weight ( P<0.005), while treatment of Ovx rats with EDP decreased body weight by 25% ( P<0.01). The immunoreactivity for CT in C cells of the Ovx rats was markedly increased. Significant decreases in the volume of C cells (by 13%; P<0.05) and serum CT (by 45%) were recorded, while the C cell number increased by 59% ( P<0.05) in relation to the corresponding controls. The treatment of Ovx rats with EDP caused conspicuous degranulation of the C cells. The cellular volume was increased by 11% and serum CT by 36% in comparison with Ovx animals. At the same time a decrease in C cell number by 29% ( P<0.05) was evident. It may be concluded that estradiol deficiency after Ovx reduced the synthesis and release of CT, while chronic treatment of these animals with EDP had a positive effect on the secretory activity of thyroid C cells.
Filipović
B
B
Institute for Biological Research "Sinisa Stanković ", 29 Novembra 142, 11060, Belgrade, Serbia and Montenegro. brankof@ibiss.bg.ac.yu
Sosić-Jurjević
B
B
Nestorović
N
N
Manojlović Stojanoski
M
M
Kostić
N
N
Milosević
V
V
Sekulić
M
M
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002116:Calcitonin / Q000097:blood; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D007150:Immunohistochemistry; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D013961:Thyroid Gland / Q000166:cytology* / Q000502:physiology*
D004967:Estrogens; D004958:Estradiol; D002116:Calcitonin; C023482:estradiol dipropionate