The effects of hypophysectomy from 24 hr to 8 weeks on the cytochemical distribution of rat: thyroperoxidase with or without subsequent TSH replacement for 1 to 3 days was examined. Peroxidase activity at the apical edge of rat thyroid follicular cells disappears within 48 hr after hypophysectomy. Subsequently apical vesicles decrease in number and become peroxidase-negative. Elements of both RER and Golgi atrophy and lose most of their peroxidase activity. Within 3 weeks only occasional elements of RER, rare cytoplasmic vesicles, and nuclear envelope retain peroxidase. Activity is more intense in follicular cells immediately adjacent to parafollicular cells. With the subcutaneous administration of TSH these changes are gradually reversed. Within 48 hr apical peroxidase reappears. At this time both RER cisternae and the Golgi apparatus show increased peroxidase as well. (Endocrinology95: 421, 1974)
No takes yet. Share an insight, caveat, or question.
Lois W. Tice (1974) studied this question.