QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Myers, G. S. Articles by Lee, M. Search for Related Content PubMed PubMed Citation Articles by Myers, G. S. Articles by Lee, M.

Effect of 6-Aminonicotinamide and of Added Vitamin A on Fusion of Embryonic Rat Palates in vitro¹

Graduate Group in Nutrition and Department of Epidemiology and International Health, University of California Medical Center, San Francisco, California

A procedure for the in vitro cultivation of embryonic rat palatal tissue, using semi-defined media, is described. Palatal fusion obtained in vitro resembles that normally seen in vivo. The effect of 6-aminonicotinamide (6 AN) a niacin inhibitor and of excess vitamin A on palatal fusion was investigated using this in vitro system. Administration of 6 AN to the mother resulted in a high incidence of failure to fuse and of partial fusion. This compound appeared to produce clefts by interfering with the ability of the shelves to fuse but not otherwise affecting their development. This effect was prevented by the simultaneous administration of nicotinamide to the mother. Addition of 6 AN to the culture medium was less effective and was not reversed by addition of nicotinamide to the medium. Histological changes were seen in most treated palates regardless of the route of administration of 6 AN. These changes could be prevented by nicotinamide, either injected or added to the culture medium, but no relation could be found between the tissue changes and the occurrence of clefts. Addition of vitamin A to the culture medium resulted in a high incidence of failures of palates to fuse. This appeared to be due to retarded development of the shelves, with failure to meet in the midline. Experiments with sliced palatal preparations indicated that the tissues were competent to fuse if they were able to come together. Alcian Blue staining and autoradiography with ³⁵SO₄ did not indicate that mucopolysaccharide synthesis or distribution or sulfur metabolism are factors involved in the vitamin A effect. Evidence is presented supporting the view that palatal fusion may be interrupted by nutritional factors operating through different mechanisms, although the end result observed at birth (cleft palate) is the same.

² Present address: Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia.

³ Present address: School of Home Economics, University of British Columbia, Vancouver, British Columbia.

Manuscript received 5 May 1967.

This article has been cited by other articles:

				G. R. Smiley and W. E. Koch Fine Structure of Mouse Secondary Palate Development In Vitro Journal of Dental Research, November 1, 1971; 50(6): 1671 - 1677. [Abstract] [PDF]

				J.F. Thompson and M.R. Schweisthal Study of Closure of the Embryonic Rat Palate In Vitro with the Effects of Certain Chemicals Journal of Dental Research, July 1, 1969; 48(4): 568 - 572. [Abstract] [PDF]