[Influence of propyl-thiouracil-induced hypothyroidism on rat gingival mucosa]

This work aimed at verifying the influence of propyl-thiouracil (PTU)-induced thyroid hormone deficiency on gingival mucosa of young male rats, measuring total protein concentration, collagen content and DNA concentration as indices of cellular population. Fifty Sprague-Dawley rats were used. The animals were grouped in: PTU-treated (i.p. 10 mg/d) and control rats (C). The experience was maintained for a period of 10 weeks. Total protein content of gingival mucosa tissue was determined by the Lowry method; hydroxyprolin rate, as prototype amino acid of collagen, was determined using the Newman method, and DNA concentration was measured by Burton's methodology. The results showed decreased amounts of PTU-treated rats gingival total protein content (PTU= 41.23 +/- 24.05 vs. C= 63.36 +/- 18.05); no alterations were seen in hydroxyprolin concentration neither in DNA content of PTU treated rats, respectively (PTU= 2.18 +/- 1.48 vs. C= 2.29 +/- 1.51) and (PTU= 0.33 +/- 0.19 vs. C= 0.46 +/- 0.41). Thus, PTU treatment promotes a decrease in total protein content of rat gingival mucosa that may be interpreted as a decrease in protein synthesis induced by the hypothyroid condition, but with no alteration either in collagen or nucleic acid rates.