甲状腺素对小鼠毛发生长周期的影响

利用Ｃ５７ＢＬ６小鼠作动物模型，观察甲状腺素对毛发生长周期的影响。选择毛发处于休止期的Ｃ５７８ＢＬ６小鼠，用不同剂量的左旋 腺素钠连续灌胃２８ｄ，并以松香／蜡混合物对小鼠背部皮肤进行拔毛诱导生长期作对照。     

再生障碍性贫血患者血清甲状腺激素水平的临床研究

采用放射免疫法检测１４３例再生障碍性贫血（ＡＡ）患者治疗前后甲状腺激素水平，并与正常人对照。结果ＡＡ患者治疗前及治疗后病情无好转时，其Ｔ３，Ｔ４明显低于对照组（Ｐ均〈０．０１），而促甲状腺素（ＴＳＨ）无显著改变（Ｐ〉０．０５），当治疗后病情明显好转或基本缓解时，Ｔ３，Ｔ４值接近正常人（Ｐ〉０．０５），ＴＳＨ也无显著改变（Ｐ〉０．０５），这种不伴ＴＳＨ升高的低Ｔ３，Ｔ４考虑为甲状腺综合征中的Ｔ３，Ｔ     

Prospectively measured thyroid hormones and thyroid peroxidase antibodies in relation to breast cancer risk

Thyroid hormones influence both normal breast cell differentiation and breast cancer cell proliferation and stimulate the angiogenesis of certain cancer forms. Several cross-sectional studies have measured thyroid hormones/autoantibodies in breast cancer ceases vs. controls, but it is difficult to determine the cause-effect direction in these studies. Only three prospective studies have reported on the subject so far. The aim of our study was to investigate prediagnostically measured levels of thyroid hormones, thyrotropin (TSH) and thyroid autoantibodies in relation to subsequent risk of breast cancer. The Malmoe Diet and Cancer study examined 17,035 women between 1991 and 1996. Blood samples were collected at baseline and free triiodothyronine (T3), free thyroxin (T4), TSH and thyroid peroxidase autoantibodies (TPO-Ab) levels were measured in 676 cases and 680 controls. Relative risks with 95% confidence intervals were assessed using a logistic regression analysis adjusted for potential confounders. Free T4 levels were positively associated with a high risk of breast cancer, and the OR for women with free T4 levels above vs. below the median was 1.40 (1.10-1.77). This association was most pronounced in overweight women (1.51:1.07-2.12). Women with high levels of TPO-Ab had a lower risk of breast cancer, but only the analysis of TPO-Ab as a continuous variable reached statistical significance. Free T4 was in our study positively associated with a high risk of breast cancer. This association was most pronounced in overweight/obese women. Women with a high level of TPO-Ab had a relatively low risk of breast cancer.     

Thyroid hormone participates in the regulation of neural stem cells and oligodendrocyte precursor cells in the central nervous system of adult rat

Oligodendrocyte development and myelination are under thyroid hormone control. In this study we analysed the effects of chronic manipulation of thyroid status on the expression of a wide spectrum of oligodendrocyte precursor cells (OPCs) markers and myelin basic protein (MBP) in the subventricular zone (SVZ), olfactory bulb and optic nerve, and on neural stem cell (NSC) lineage in adult rats. Hypo- and hyperthyroidism were induced in male rats, by propyl-thio-uracil (PTU) and L-thyroxin (T4) treatment, respectively. Hypothyroidism increased and hyperthyroidism downregulated proliferation in the SVZ and olfactory bulb (Ki67 immunohistochemistry and Western blotting, bromodeoxyuridine uptake). Platelet-derived growth factor receptor alpha (PDGFalpha-R) and MBP mRNA levels decreased in the optic nerve of hypothyroid rats; the same also occurred at the level of MBP protein. Hyperthyroidism slightly upregulates selected markers such as NG2 in the olfactory bulb. The lineage of cells derived from primary cultures of NSC prepared from the forebrain of adult hypo- and hyperthyroid also differs from those derived from control animals. Although no difference of in vitro proliferation of NSCs was observed in the presence of epidermal growth factor, maturation of oligodendrocytes (defined by process number and length) was enhanced in hyperthyroidism, suggesting a more mature state than in control animals. This difference was even greater when compared with the hypothyroid group, the morphology of which suggested a delay in differentiation. These results indicate that thyroid hormone affects NSC and OPC proliferation and maturation also in adulthood.     

Influence of the pineal gland and circadian rhythms in circulating levels of thyroid hormones of male hamsters

Thyroxin (T4) and triiodothyronine (T3) were measured by radioimmunoassay in serum of hamsters sacrificed at 4-hr intervals throughout the daily light-dark cycle (14L/10D). Both T4 and T3 concentrations increased significantly during the L period of the daily cycle and decreased during the D period of the cycle; A.M. versus P.M. differences in free thyroxin indices (FTI) were also studied using the T4 and T3 uptake assays of Nuclear Medical Laboratories (Dallas, Texas). The free thyroxin index was significantly greater in serum samples of hamsters sacrificed at 7 P.M. than at 7 A.M. (lights on at 6:30 A.M.). Serum taken at 7 P.M. had less unsaturated binding sites than serum taken at 7 A.M. No significant A.M. versus P.M. differences in free thyroxin index were found in blind hamsters, although blind hamsters had significantly lower T4 and FTI than controls. Placing melatonin in the drinking water at a dose of 80 μg/ml did not significantly influence hormone levels. The greatest difference in hormone concentrations between control and blinded hamsters was found in P.M. samples. Blind hamsters had FTIs that were 48% of P.M. controls. Pinealectomy prevented the effects of blinding on T4 levels and FTIs.     

抑乳汤治疗甲减患者泌乳素升高的临床观察

目的观察中药抑乳汤对女性原发性甲状腺机能减退(简称甲减)患者血清泌乳素升高的治疗作用.方法治疗组用抑乳汤配合甲状腺素片治疗;对照组用单纯甲状腺素片治疗.治疗前后用放射免疫法进行甲状腺素(T4)、游离甲状腺素(FT4)、促甲状腺激素(TSH)和泌乳素(PRL)测定.结果两组临床近期疗效总有效率无明显差异(P>0.05),但治疗组PRL的下降率及远期疗效的复发率、不良反应率与对照组相比均有显著性差异(P<0.05,P<0.01).结论抑乳汤配合甲状腺素片是治疗原发性甲减伴高PRL血症的有效方法.PRL水平的升高与下丘脑-垂体-甲状腺轴的激素分泌失调有一定的内在联系,两者的关系值得探讨.     

蛇床子素和蛇床子总香豆素对肾阳虚大鼠血清甲状腺激素和促甲状腺激素的影响

采用醋酸氢化可的松造成肾阳虚模型大鼠，以蛇床子素（ｏｓｔｈｏｌ，ＯＳＴ）和蛇床子总香豆素（ｔｏｔａｌ－ｃｏｕｍａｒｉｎｓ，ＴＣＲ）给药，测定大鼠血清促甲状腺激素（ＴＳＨ）和三种甲状腺激素Ｔ３、反Ｔ３（ｒＴ３）及Ｔ４的浓度。结果，肾阳虚模型大鼠与正常大鼠比较，ＴＳＨ、Ｔ３、ｒＴ３和Ｔ４都显著降低（Ｐ均＜０．０１）；用药大鼠与肾阳虚模型大鼠比较，上述４项指标都有显著性提高（Ｐ＜０．０１或Ｐ＜０．０５）。提示ＯＳＴ和ＴＣＲ可以提高肾阳虚模型大鼠的腺垂体－甲状腺轴功能。     

甲状腺素引起大鼠胰岛β细胞功能改变的机制研究

研究发现,甲状腺素(thyroxin,T4)水平过高可引起大鼠糖耐量异常.在此病理过程中,产生了胰岛素分泌水平的下降而非胰岛素抵抗,并且胰岛素水平的下降是因为胰岛素分泌水平下降而并非胰岛素清除率升高[1].临床资料报道,部分甲亢病人同时伴有糖耐量降低,甚至出现糖尿病(diabetes mellitus, DM)[2].但其机制的研究尚未见报道.本文初步探讨了甲状腺素引起大鼠胰岛β细胞功能改变的机制.