ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Administration of isoproterenol (IPR), twice daily for five days, to five day old rats resulted in a hypertrophy and hyperplasia of the submandibular gland as indicated by an increase of the total DNA, RNA, and protein contents of the gland. Four different cell types, the acinar cell, the terminal tubule cell, the intercalated duct cell and the striated duct cell were distinguished in 1 μ thick, Epon-embedded sections and their rates of proliferation were estimated from radioautographs prepared following the incorporation of 3H-thymidine. IPR treatment increased both the frequency and the absolute number of the acinar cells as compared to those of control animals. Concomitant with this there was a decrease in the number of terminal tubule cells from 50% in the control to about 15% in the IPR-treated rat submandibular gland. These findings indicate that IPR accelerated the postnatal differentiation and proliferation of acinar cells. Eleven days after withdrawal of the drug the gland showed chemical and morphological evidence of regression of the IPR-induced hypertrophy and hyperplasia and the numbers of acinar cells and terminal tubule cells in the glands of control and IPR-treated rats were the same. Thus the IPR-induced advanced differentiation of the gland was not maintained after the cessation of the IPR-administration.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091770206
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