Suppressing effect of cysteamine on the TSH-stimulated mitotic activity of the rat thyroid follicular cells in vivo.
We have examined the effect of the thiol agent-cysteamine, known to deplete the hypothalamus, the pancreas, the gut of somatostatin--on the basal and TSH-stimulated mitotic activity of the thyroid follicular cells (TFC) in adult male rats in vivo. The animals of different groups were administered cysteamine alone (300 mg/kg BW, s.c.), TSH alone (2IU, i.p.), or cysteamine with TSH jointly, the former agent being injected 2 hrs prior to the latter. In order to evaluate the thyroid mitotic activity, the metaphase-arrest technique was used in the study. It was shown that: 1. TSH significantly increased the mitotic activity of TFC, as compared to controls, 2. cysteamine alone had no effect on the TFC proliferation, 3. unexpectedly, cysteamine, when administered 2 hrs prior to TSH, suppressed the stimulatory effect of TSH on the mitotic activity of TFC.
Zerek-Melen
G
G
Department of Experimental Endocrinology and Hormone Diagnostics, Medical Academy of Lodz, Poland.
Sewerynek
E
E
Szkudlinski
M
M
Lewinski
A
A
Krotewicz
M
M
Fryczak
J
J
Pawlikowski
M
M
D000818:Animals; D003543:Cysteamine / Q000494:pharmacology*; D008297:Male; D008938:Mitosis / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects*; D013972:Thyrotropin / Q000037:antagonists & inhibitors* / Q000494:pharmacology
D003543:Cysteamine; D013972:Thyrotropin