Calcitonin cells and unusual follicles of the thyroid of the Indian grey mongoose, <i>Herpestes edwardsi</i> (Geoffroy)

Abstract

Histological preparations of thyroid, parathyroid and thymus glands of Herpestes edwardsi were examined for calcitonin cells. They reveal that (1) the thyroid calcitonin cells are oval, rounded and rarely elongated in shape; these cells and their nuclei are distinctly larger than those of the follicular cells and their nuclei; (2) calcitonin cells are unevenly distributed in the thyroid, with the result that certain portions of the thyroid are completely devoid of these cells; (3) on an average, calcitonin cells are in a ratio of 10–15 cells/100 follicular cells; (4) the parathyroid and thymus glands do not display calcitonin cells, and (5) the thyroid gland displays unusual follicles of two categories, (a) follicles with ciliated epithelial cells and (b) follicles with squamous epithelium.

Occurrence of calcitonin cells and cysts in the parathyroid of the house shrew, <i>Suncus murinus</i>

“…• The cysts of parathyroid IV appear to be similar to those reported by other investigators under different names from mammalian thy roid -ultimabranchial cysts or ducts or second system of follicles [Watzka, 1933;Van Dyke, 1944, 1955, 1959Axelrad and Leblond, 1955;Sehe, 1966;Calvert, 1972], mixed follicle [Calvert and Isler, 1970;Neve and Wollman, 1971;Wollman and Neve, 1971] and unusual follicles [Swarup and Das, 1976]. In S.murinus the cysts are seen invariably restricted to the internal parathyroid.…”

Thyroid Calcitonin Cells and Unusual Follicles in the Fox

“…The lumina of the unusual follicles in the fox contain cell debris similar to those reported by Wollman and Neve [1971] and Swarup and Das [1976],…”

“…Similar chains of unusual follicles have been seen in the thyroid of ground squirrel [Sehe, 1966], mouse [Wetzel and Wollman, 1969], mon goose [Swarup and Das, 1976] and in the parathyroid of the house shrew ,…”

“…The ratio between the C cells and the thyroid follicular cells seems to vary consid erably in the various mammalian species: rat (30/100 follicular cells) [Kameda, 1968], dog (30-90/100 follicular cells) [Kameda, 1968], mongoose (10-15/100 follicular cells) [Swarup and Das, 1976], jackal (12-20/100 follicular cells) [Tewari and Swarup, 1979] and house shrew (35-57/100 follicular cells) , In the present study the ratio is 18-27 C cells/100 follicular cells.…”

“…The C cells are distributed unevenly as in the dog [Kameda, 1968], rabbit, mice and cat [Kameda, 1971b], human [McMil lan et al, 1974], mongoose [Swarup and Das, 1976], opossum [Fortney, 1978], jackal [Tewari and Swarup, 1979], house shrew and mouse [Wechbanjong et al, 1979], Pento [1978], however, has reported a uniform calcitonin activity in the thyroid gland of the cow indi cating an uniform distribution of C cells.…”