Early calcitonin hypersecretion and C cell hyperplasia in rats with high incidence of C cell tumors (Wag/Rij).
Wag/Rij rats, a Wistar-derived strain, develop on aging a spontaneous medullary thyroid carcinoma which shows many morphological similarities to the human neoplasm. Using biochemical and histological methods, we studied calcitonin secretion and C cell distribution in young and adult Wag/Rij rats, to characterize possible modifications in calcitonin synthesis and secretion as compared to the original Wistar strain. During the period investigated, the mean basal circulating levels of calcitonin of both sexes were not significantly different between the two strains, although the Wag/Rij rats tended to have higher values. After a calcium challenge, the circulating calcitonin levels increased normally in the Wag/Rij strain as compared to Wistar rats of the same ages. Histological observations of their thyroids revealed a significant C cell hyperplasia, along with a weak immunostaining in some of the cells, due to a lack of secretory granules. Thus, in addition to the ability of developing C cell tumours on aging, the Wag/Rij strain is characterized by an early C cell hyperplasia leading to an increase of calcitonin secretion after a provocative secretion test.
Khattab
M
M
Groupe d'Endocrinologie cellulaire et Evolution, URA 21 CNRS, Université Paris-Sud, Orsay, France.
Pidoux
E
E
Volle
G E
GE
Bouizar
Z
Z
Calmettes
C
C
Milhaud
G
G
Moukhtar
M S
MS
Treilhou-Lahille
F
F
D000375:Aging; D000818:Animals; D002116:Calcitonin / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D004198:Disease Susceptibility; D005260:Female; D006965:Hyperplasia / Q000378:metabolism; D008297:Male; D008854:Microscopy, Electron; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D013045:Species Specificity; D013961:Thyroid Gland / Q000187:drug effects / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000473:pathology*
D002116:Calcitonin; D002118:Calcium