Panciera D L, Atkins C E, Bosu W T, MacEwen E G
Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison 53706.
Am J Vet Res. 1990 Jan;51(1):27-31.
To determine the effects of long-term thyroxine treatment, histomorphometric analysis was performed on the pituitary and thyroid glands of healthy dogs, dogs treated for 9 weeks with a replacement dose of L-thyroxine, and dogs at 6 weeks after cessation of thyroxine treatment. In treated dogs, the volume density of thyrotropes decreased during thyroxine treatment and increased 6 weeks after cessation of treatment, compared with thyrotropes of healthy nontreated dogs. The activity of the thyroid gland was decreased in dogs during thyroxine treatment, as evidenced by decreases in epithelial volume density, epithelial height, and follicular area, and increase in colloid volume density, compared with thyroid gland activity in nontreated dogs. After cessation of thyroxine treatment, the thyroid gland had decreased colloid area, follicular area, and epithelial volume density, and increased interstitial volume density, compared with the thyroid gland of healthy nontreated dogs. Thyroxine treatment resulted in suppression of pituitary thyrotropes and thyroid follicular activity.
为确定长期甲状腺素治疗的效果，对健康犬、接受替代剂量L-甲状腺素治疗9周的犬以及停止甲状腺素治疗6周后的犬的垂体和甲状腺进行了组织形态计量分析。与未接受治疗的健康犬的促甲状腺激素细胞相比，接受治疗的犬在甲状腺素治疗期间促甲状腺激素细胞的体积密度降低，停止治疗6周后增加。与未治疗犬的甲状腺活动相比，甲状腺素治疗期间犬的甲状腺活动降低，表现为上皮细胞体积密度、上皮细胞高度和滤泡面积减小，胶质体积密度增加。停止甲状腺素治疗后，与未接受治疗的健康犬的甲状腺相比，甲状腺的胶质面积、滤泡面积和上皮细胞体积密度减小，间质体积密度增加。甲状腺素治疗导致垂体促甲状腺激素细胞和甲状腺滤泡活动受到抑制。
