Biomedical subjects

C G Bellows

Publications and source records attributed to C G Bellows.

38 records · Page 3Linked to original sources

PubMed1978

The stability of vitamin A-induced metaplasia of mouse vibrissa follicles in vitro.

Tests were made of the stability of the previously described glandular morphogenesis and mucous metaplasia of embryonic mouse vibrissa follicles produced in vitro by excess vitamin A. The changes in individual follicles were observed in living tissue explants and serial sections. Upper lip skin of 13.5-day embryos underwent budding from vibrissa follicles to form branching glands which secreted mucus after 10--14 days in medium containing 4.7 microgram/ml retinol. If this medium was replaced with standard medium after 7 days, glandular morphogenesis and metaplasia continued unaffected, although some hair follicle bases returned to their original morphogenetic program. Similar results were obtained with skin of 13-day embryos treated with vitamin A (6.0 MG/ML) for only 3 days. The moderate degree of glandular morphogenesis in 15-day skin with vitamin A (4.7 microgram/ml) was not altered by the simultaneous addition of a high dose of cortisol (18 microgram/ml). It is suggested that the initiation of glandular morphogenesis of follicles differs from the initiation of mucous metaplasia in embryonic chick epidermis by vitamin A, in that it resembles a new secondary embryonic induction rather than a modulation of the epithelium.

Animals↗

PubMed1977

Histochemical evidence of mucosubstances in the metaplastic epidermis and hair follicles produced in vitro in the presence of excess vitamin A.

Pieces of upper lip and lower jaw from 13-day old mouse embryos grown in organ culture with excess vitamin A showed metaplastic changes in epidermis and hair follicles after 7 to 21 days. Changes were less marked in upper lip explants from 15-day old embryos. Areas of keratinizing epidermis showed a much higher incidence of Alcian blue-positive bodies when excess vitamin A was present. Histochemical tests with Alcian blue at critical electrolyte concentrations indicated moderately sulfated acidic mucosubstances in these bodies. Other patches of epidermis were transformed into stratified cuboidal epithelium producing PAS-positive, Alcian blue-negative, mucosubstances. The hair follicles, transformed by vitamin A into glands, developed three types of epithelium with apical granules, luminal borders and occasional goblet cells, all showing mucosubstances. Tests suggest that both metaplastic epidermis and glands secrete either neutral mucosubstances or non-sulfated acidic mucosubstances. Another response to vitamin A was a rapid loss of glycogen, particularly in hair follicles and the epidermal basal layer. It was concluded that excess vitamin A alters not only the morphogenesis but also the distribution and synthesis of polysaccharides in developing skin.

Animals↗