Rapid proliferative response of rat thyroid gland to a single injection of TSH in vivo.
Mitotic and labelling indices were studied in the thyroid follicular cells of the male rat within the first hour after a single injection of TSH or TSH vehicle, using the metaphase arrest agent vincristine sulphate. There was a significant increase in metaphase index over control values 5, 15, 30 and 60 min after injection of TSH. There was no significant change in the tritiated thymidine labelling index in TSH-treated rats in comparison with vehicle-injected controls. None of the metaphase figures was labelled, showing that G2 in this tissue is longer than 2 h.
Bybee
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Department of Physiology, Trinity College, Dublin 2, Ireland.
Tuffery
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AR
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D007700:Kinetics; D008297:Male; D008677:Metaphase / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects*; D013972:Thyrotropin / Q000494:pharmacology*
D013972:Thyrotropin