猪甲状腺形态的年龄变化

我们对哈白猪、长白猪、三江猪、东北民猪四个品种的猪,进行了甲状腺形态年龄变化的研究。主要结果如下:甲状腺重量的增加大致和体重的增加一致。甲状腺长度的增加,只在三十公斤以前时期和体重的增加相一致,以后则减慢。甲状腺宽度及厚度的增加不与体重的增加相一致,而比体重增加的慢。甲状腺滤泡的相对数量(在10×40倍视野内)初生时最多,以后随年龄而逐漸减少。有腔的甲状腺滤泡平均直径在初生时最小,以后随年龄而增加。有腔滤泡上皮在初生时较薄,为低立方形,从15公斤以后则增厚而变为立方形,但因机能状态不同,在以后各时期都可能有薄的近于扁平状的,也可能有厚的近于柱状的上皮。存在于滤泡间的未分化的上皮细胞及细胞团在初生时最发达,在120公斤时期只存在于局部地区。滤泡旁细胞数量非常少,未见有品种变化和年龄差异,间质在初生时最少,所以这时的滤泡间距极小。间质在以后随年龄而增加,相应地滤泡间距也增大,但在局部地区之间差异很大。甲状腺形态在性别上及品种间差异不显著。

AGE-DEPENDENT CHANGES OF THE MORPHOLOGY OF THE THYROID GLANDS IN PIGS

We had studied age-dependent changes on the morphology of the thyroid glands of four breeds—Harbin White, Landrace, Three rivers (San Jiang) and Native pigs. Essential results were as follows: 1. Increase of weight of the thyroid glands was essentially in parallel with increase of body weight. 2. Increase of length of the thyroid glands was in accord with increase of body weight only prior to 30kg stage there after length increase of the thyroid glands slackened. 3 Increase in breadth and thikneess of the thyroid glands was not in parallel with that of body weight, but was slower. 4. Relative number (in 10×40 field) of the follicles was the most at birth, thereafter it gradually reduced with age. 5. Mean diameter of the follicles with lumen was the least at birth, thereafter it increased with age. 6. The epithelium of the follicles with lumen was thiner and appeared as alow cuboid shape at birth, After 15kg stage, its thickness had increased so that it became cuboid in shape, but it may appear as a thin squamcus-like epithelium, or a thick cuboid like epithelium during subsequent stages depending on their functional differences. 7. The undifferentiated epithelial cells as well as cell groups between follicles were highly developed at birth, while at 120kg stage, they were fond only in local zones. 8. Number of parafollicular cells were extermely scarce, no differences among breeds or ages were detected. 9. Stomata were the least at birth, so that intervals between folliclesincreased proportionally, with considerable variations in local zone. 10. No significant difference between sex or breed were found in the morphology of thyroid glands