A Morphometric Study on the Endometrium of Rat Uterus in Hypothyroid and Thyroxine Treated Hypothyroid Rats

Hypothyroidism increases the rate of pregnancy loss. Other manifestations include menstrual disorder, and infertility. Serum levels of gonadotropins are low in hypothyroid patients. Though studies of uterine ultrastructure are well established as approaches to investigating the pathophysiology of infertility, they have scarcely been extended to the study of hypothyroid related infertility. The present study investigates the effect of hypothyroidism on the ultrastructure of uterine epithelium. Three groups of Wistar rats were studied. Two groups were initially made hypothyroid using methimazole, and the third group was an untreated control. One hypothyroid group was given daily injections of thyroxine for six weeks. The uteri were removed in all three groups, and processed for transmission electron microscopy and morphometry. It was found that absolute epithelial cell volume was decreased in hypothyroidism.

The volume of the nucleus had decreased though its relative volume in the cell had increased. The height of the luminal epithelium in hypothyroid rats also decreased by (33.8%) as compared with controls. Basement membrane thickness was significantly increased in hypothyroidism. The changes were all substantially abrogated by the administration of thyroxine. This study suggests that thyroid hormones might be importantly concerned in the maintenance of the normal structure of uterine epithelial cells.     

甲状腺素联合多奈哌齐对成年期甲减大鼠海马内超微结构及 synaptotagmin-1表达的影响

目的：观察甲状腺素（T4）联合多奈哌齐（DON）治疗对成年期甲状腺功能减退症（简称甲减）大鼠海马内超微结构及突触结合蛋白 synaptotagmin-1（syt-1）表达的影响。方法饮0．05％丙基硫氧嘧啶（PTU）水建立成年期大鼠甲减模型共6周,第5周起,T4治疗组给予腹腔注射 T46μg／100 g 体重、DON 治疗组饮0．005％ DON 水,联合治疗组给予 T4＋DON 治疗,对照组及甲减组每日腹腔注射等量生理盐水。采用放射免疫法测定血清甲状腺素水平,透射电镜观察海马内超微结构,Western blot 方法分析海马内 syt-1的表达水平。结果甲减组、DON 治疗组大鼠血清甲状腺激素水平明显降低（P ＜0．01）,T4治疗组、联合治疗组与对照组差异无统计学意义;电镜下甲减大鼠海马内神经元中线粒体呈现明显空泡变性、游离核糖体稀疏、突触结构受损、突触小泡数量减少,T4或 DON 治疗后上述损伤有所改善,而联合治疗恢复后表现最接近对照组;甲减大鼠海马内 syt-1蛋白表达量明显降低（P ＜0．01）,单独 T4或 DON 治疗后表达仍下降（P ＜     

甲状腺功能减退症对成年期SD大鼠肾脏超微结构的影响及L-T4替代治疗的效果

目的 观察甲状腺功能减退症(简称甲减)对成年期 SD大鼠肾脏超微结构的影响及左旋甲状腺素(L-T4)替代治疗的效果.方法 将30只健康3月龄雄性SD大鼠适应性喂养1周,随机均分为对照组、甲减组和L-T4治疗组.通过丙基硫氧嘧啶饮水法建立甲减模型,共6周.从第5周开始,L-T4治疗组大鼠给每日予L-T4腹腔注射(剂量按体质量6 μg/100 g计算);对照组及甲减组每日予同等剂量生理盐水腹腔注射.造模结束后对所有大鼠进行称重,之后使用放射免疫法检测三组大鼠甲状腺功能,同时使用透射电镜完成肾脏超微结构观察.结果 造模前,三组大鼠体质量水平比较差异无统计学意义;造模结束后,对照组、甲减组和L-T4治疗组三组大鼠体质量较造模前各增加了 48. 14％、 22. 18％ 、34. 90％.造模后三组间体质量比较显示:甲减组、 L-T4治疗组大鼠体质量显著低于对照组(P<0. 05);与对照组相比,甲减组大鼠血清甲状腺激素(T3、T4)水平明显降低,促甲状腺素水平显著升高(P<0.01) ,L-T4治疗组血清甲状腺激素及促甲状腺素水平与对照组相比差异无统计学意义;电镜下观察显示对照组大鼠肾小球足细胞结构完整,足突排列清晰,线粒体发达、内部嵴结构清晰;甲减组大鼠肾小球基底膜结构不规则,足细胞明显肿胀、融合,内部细胞器结构不清晰,线粒体明显空泡变性,内部嵴断裂消失,粗面内质网有脱颗粒现象,间质水肿;L-T4治疗组以上超微结构改变明显改善.结论 甲减可致成年期SD大鼠肾脏超微结构发生病理学损害,L-T4替代治疗有利于上述损伤的恢复.     

甲状腺素联合多奈哌齐对成年期甲状腺功能减退症大鼠海马syntaxin-1的影响

目的 观察甲状腺素( T4 )联合多奈哌齐对成年期甲状腺功能减退症(甲减)大鼠的海马内突触前膜相关蛋白1 (syntaxin-1)表达的影响,探讨甲减脑损伤及可能的恢复机制. 方法 44只SD大鼠随机分为4组:对照组、甲减组、T4替代治疗组及T4和多奈哌齐联合治疗组. 通过饮水给予丙基硫氧嘧啶0. 05%建立成年期大鼠甲减模型共6 周. 第5周开始,对照组腹腔注射等量生理盐水, T4替代治疗组每日给予左旋甲状腺素(L-T4) 6 μg/100 g 体重(BW)腹腔注射,联合治疗组每日给予6 μg/100g BW L-T4腹腔注射及饮用水中加入0. 005%多奈哌齐. 采用免疫组织化学法和West-ern blot法分析4 组大鼠海马syntaxin-1 的表达情况. 结果与对照组比较,甲减组大鼠血清三碘甲状腺原氨酸( T3 )、T4水平减低,促甲状腺激素(TSH)水平升高(P<0. 01),海马内syntaxin-1在CA1、CA3 各层及齿状区多形层( DG-PL)表达显著增加( P <0. 01 );T4 替代治疗后,血清 T3、T4 和TSH水平恢复至正常水平, syntaxin-1 蛋白的表达未完全恢复到对照组水平(P<0. 05);T4联合多奈哌齐治疗后syntax-in-1蛋白表达与对照组比较差异无统计学意义. 结论 T4联合多奈哌齐治疗可以修复成年期甲减导致的脑损伤.     

Raised plasma glutathione S-transferase values in hyperthyroidism and in hypothyroid patients receiving thyroxine replacement: evidence for hepatic damage

Using plasma glutathione S-transferase measurements hepatocellular integrity was assessed in groups of hyperthyroid and hypothyroid patients before and after treatment. Ten of 14 hyperthyroid patients had clearly raised plasma glutathione S-transferase values at presentation and in each patient treatment with either iodine-131 or carbimazole resulted in a significant fall in glutathione S-transferase. The eight hypothyroid patients had normal glutathione S-transferase values at presentation and all showed a significant increase in these after thyroxine replacement therapy. In three of these patients in whom standard doses of replacement therapy were associated with a raised free thyroxine (T4) concentration but normal total and free triiodothyronine (T3) values glutathione S-transferase was increased. Similar though less consistent changes were seen in the results of standard chemical tests of liver function. It is concluded that hyperthyroidism may produce subclinical liver damage in a high proportion of patients and that this resolves with effective treatment. More important, the data suggest that hypothyroid patients receiving thyroxine replacement therapy may have similar subclinical liver damage. Patients receiving thyroxine should be monitored by the measurement of free, not total hormone concentrations, and in those in whom free T4 is raised the dose of thyroxine should be reduced. It would also be expedient to include periodic biochemical assessment of liver function in patients receiving thyroxine.     

Coagulation profiles in hypothyroid and hyperthyroid female patients in Sudan

OBJECTIVE: To evaluate disturbances in the coagulation system in female patients with thyroid disorders in order to assess the effects of thyroid diseases on coagulation parameters. METHODS: This study was conducted in Khartoum state, the national capital of Sudan from February 2007 and February 2008 The study included 30 patients with clinical hypothyroidism, and 30 patients with sub- clinical hypothyroidism (21 of them were recruited before starting the treatment). Also, the study included 30 patients with clinical hyperthyroidism, 30 with sub-clinical hyperthyroidism, (37 of them were recruited before starting the treatment) and 30 normal individuals as the control group. Prothrombin time (PT), activated partial thromboplastin time, fibrinogen level, and platelets count were performed in patients and control samples. RESULTS: A significantly decrease in PT was observed in hypothyroid patients, and hyperthyroid patients compared to the control group. Activated thromboplastin time was significantly decreased only in hyperthyroid patients, compared to the control group. Moreover, fibrinogen level was significantly increased in hyperthyroid patients compared to hypothyroid patients. CONCLUSION: The study concluded that minor coagulation abnormalities were observed in both subclinical hypo- and hyperthyroidism compared to clinical hypo- and hyperthyroidism. Platelets count was also slightly decreased in both types of the disease. There was no significant effect of the treatment and age of such patients on the measured parameters. The study recommended to screen female patients with hypo- and hyperthyroidism for coagulation defect, to avoid the risk of such complications.     

A retrospective study on hypothyroid patients.

A retrospective study of 58 hypothyroid patients attending the Endocrine Clinic, University Hospital of the West Indies, Jamaica, between July and August 1989, was undertaken. The age range at initial presentation varied from one month to eighty-four years. The majority of cases (51 or 87.9%) were between 21 and 70 years. There were 50 females (86.2%) and 8 males (13.8%). The underlying causes were idiopathic hypothyroidism (35 or 60.3%), posthyroidectomy (13 or 22.4%), post I131 therapy (6 or 10.4%), panhypopituitarism (3 or 5.2%), hypophysectomy (1 or 1.7%). Biochemical parameters used in diagnosis were serum thyroxine (T4) and thyroid-stimulating hormone (TSH). Forty-six patients (79.2%) had elevated TSH, indicative of a high correlation of elevated TSH with hypothyroidism. Duration of symptomatology prior to diagnosis was one year in 27 patients (46.5%), 2-10 years in 23 (39.6%) and 10 years in 4 cases (6.9%). The major presenting signs and symptoms were lethargy (20 or 34.5%), anaemia (mixed normochromic, microcytic (16 or 27.6%), slow relaxation of tendon reflexes (16 or 27.6%), coarsening of skin (15 or 25.9%), weight gain 10 or 17.2%), hoarseness (9 or 15.5%) and psychiatric symptoms (7 or 12%). The known association of primary hypothyroidism with other autoimmune disorders was not borne out in this study. The time-lapse in diagnosis from symptomatology emphasized the need for clinicians to be more alert to the subtle and varied presentation of hypothyroidism.     

Heart rate variability and its response to thyroxine replacement therapy in patients with hypothyroidism

目的　测定甲状腺功能减退 (甲减 )患者心率变异 (HRV)及观察甲状腺素替代治疗后的变化。方法　记录 38例甲减患者与 2 1例正常者 2 4小时动态心电图 ,并进行HRV分析。 18例甲减患者治疗 3月后重复HRV测定。结果　甲减时 ,HRV的时阈指标较对照组明显降低 ;频阈指标中 ,高频功率 (HF)较对照组明显增高 ,而低频 (LF)与HF比值较对照组显著减低。甲减患者经甲状腺素替代治疗后 ,HRV时阈指标和频阈指标均明显改善 ,且与FT3和FT4 的恢复程度相一致。结论　甲减时 ,自主神经活动明显改变 ,且以迷走神经兴奋性增加占优势。这种自主神经异常在甲状腺素替代治疗后可部分改善。     

甲状腺激素联合多奈哌齐治疗对成年甲减大鼠额叶SNAP-25的影响

目的 研究甲状腺激素联合多奈哌齐治疗对成年甲减大鼠额叶突触相关蛋白25(SNAP-25)的表达的影响.方法 将50只成年健康SD大鼠随机分为5组:对照组(CON)、甲减组(Hypo)、多奈哌齐组(DON)、左甲状腺激素钠组(L-T4)、左甲状腺激素钠联合多奈哌齐组(L-T4+DON);除对照组外,其余4组通过含0.05℅丙基硫氧嘧啶(PTU)饮用水喂养6周诱导成年期甲减大鼠模型;DON组、L-T4组、L-T4+DON组分别予多奈哌齐、左甲状腺激素钠、左甲状腺激素钠联合多奈哌齐治疗2周后,放射免疫法测定血清甲状腺激素水平,免疫组化法、Western blot法观察大鼠额叶SNAP-25的表达.结果 与CON组相比,Hypo组大鼠血清三碘甲状腺原氨酸(T3)、四碘甲状腺原氨酸(T4)水平显著降低(P<0.01),促甲状腺激素(TSH)显著上升(P<0.01);额叶SNAP-25的表达水平显著高于CON组(P<0.05).L-T4组与CON组比较,血清T3、T4、TSH差异无统计学意义;SNAP-25的表达升高(P<0.05).DON组与CON组比较,血清T3、T4、TSH差异有统计学意义(P<0.01);SNAP-25的表达升高(P<0.05).L-T4+DON组与CON组比较,血清T3、T4、TSH差异无统计学意义;SNAP-25的表达差异无统计学意义.结论 甲状腺激素联合多奈哌齐治疗能有效地恢复成年甲减大鼠额叶SNAP-25的表达.     

Thyroxine, methimazole, and thyroid microsomal autoantibody titres in hypothyroid Hashimoto's thyroiditis

Ten hypothyroid patients with Hashimoto's thyroiditis were treated with methimazole 30 mg in addition to thyroxine 0.15 mg daily. Another 10 hypothyroid patients with Hashimoto's thyroiditis were given thyroxine 0.15 mg alone. After 22 weeks of treatment significant decreases in thyroid microsomal autoantibody titres were observed in both groups (p less than 0.01). There was no difference in the mean change in titre between the two groups. When the patients treated with methimazole were subsequently given thyroxine 0.15 mg alone for a further 22 weeks no additional change in titre was observed. The data suggest that thyroxine, by normalising serum thyroid stimulating hormone concentrations, may reduce the autoantigenic properties of the thyrocytes with a subsequent decrease in autoantibody titres.     

实验性甲状腺机能低下大鼠附睾上皮主细胞的超微结构改变

本文应用电镜技术观察了实验性甲状腺机能低下ＳＤ大鼠附睾上皮超微结构的改变。结果显示各段主细胞超微结构均存在不同程度的退行性改变，呈现出顶部小泡及微绒毛减少；线粒体肿胀；高尔基复合体结构紊乱、数量明显减少；次级溶酶体和髓样结构增多，内质风扩张和空泡化。头、体段细胞质中脂滴沉积。提示附睾正常结构和功能的维持需要适当的甲状腺素存在。     

甲状腺素对胎鼠脑bcl—2和bax基因表达的影响

目的　研究甲状腺素对胎鼠脑bcl 2和bax基因表达的影响。方法　采用丙基硫氧嘧啶灌胃制备甲减孕鼠模型 ,出生后小鼠即为先天性甲减鼠 ,另一组出生后即日起用腹腔注射T4,剂量为 2 μg/ 10 0g·d-1(替代组 ) ,采用逆转录 -聚合酶链反应检测胎鼠出生后 1、5、10d胎鼠bcl 2和bax基因的表达。结果　bax基因在甲减胎鼠脑第 1天表达最高 ,随着鼠龄增长 ,表达降低 ;正常第 1天胎鼠及替代组胎鼠脑未检测到bax表达 ;bcl 2基因在第 1天甲减胎鼠表达高于正常对照组 ;第 5天、第 10天降低 ;bcl 2在替代组鼠脑中表达较甲减组高。结论　甲状腺激素对bcl 2和bax基因表达的不同影响 ,在脑细胞凋亡中有重要的作用。     

甲状腺素联合多奈哌齐对成年期甲状腺功能减退症大鼠额叶乙酰胆碱、munc-18的影响

目的：观察甲状腺素联合多奈哌齐对成年期甲状腺功能减退症(简称甲减)大鼠额叶内乙酰胆碱含量以及munc-18表达的影响,探讨甲减脑额叶损伤及恢复的可能分子机制。方法采用给予含0．05%丙基硫氧嘧啶的饮用水6周建立大鼠甲减模型。自第5周起,给予多奈哌齐、甲状腺素或甲状腺素联合多奈哌齐治疗2周,采用放射免疫法检测血清甲状腺激素水平,碱性羟胺比色法测定额叶内乙酰胆碱含量,免疫组化法检测额叶内munc-18的分布与表达。结果甲减组、多奈哌齐治疗组大鼠血清三碘甲状腺原氨酸(T3)、四碘甲状腺原氨酸(T4)水平显著减低、促甲状腺激素( TSH)水平明显增加( P<0．01),甲状腺素治疗组、联合治疗组T3、T4、TSH水平与正常对照组相比差异无统计学意义;甲减组大鼠额叶内乙酰胆碱含量下降(P<0．05),多奈哌齐治疗组、甲状腺素治疗组、联合治疗组乙酰胆碱含量均恢复至正常水平,其中联合治疗组有进一步恢复趋势;甲减组、多奈哌齐治疗组大鼠munc-18在额叶内Ⅱ、Ⅲ、Ⅳ、Ⅴ层表达下降(P<0．05)。其中,以Ⅲ/Ⅴ层下降最为显著(P<0．01),甲状腺素治疗组munc-18表达仍下降(P<0．05),联合治疗组额叶内munc-18表达正常。结论多奈哌齐可以改善甲状腺功能减退引起的额叶内乙酰胆碱含量改变;甲状腺素联合多奈哌齐治疗有利于成年期甲状腺功能减退造成的额叶内胆碱含量改变和突触蛋白损伤的恢复。     

甲状腺功能异常患者的性激素水平变化分析

目的:观察甲状腺功能亢进(甲亢)和甲状腺功能减退(甲减)患者性激素水平的变化,以探讨其临床意义.方法:用化学发光方法分别检测甲状腺激素和性激素的水平.结果:女性甲亢和甲减组的FSH、LH较对照组明显升高.男性甲亢组和甲减组E2均较对照组明显升高,甲减组T明显下降;女性甲亢组和甲减组E2均较对照组降低.PRL在女性甲亢组和甲减组中均升高,男性甲减组升高.结论:由于甲状腺激素水平的改变,而导致下丘脑2垂体促性腺激素轴的调节功能紊乱,男性可能出现性功能下降和男性不育症,女性可能出现月经紊乱和女性不孕症.     

Effect of somatostatin on thyrotropin, prolactin, growth hormone and insulin responses to thyrotropin releasing hormone and arginine in healthy, hypothyroid and acromegalic subjects.

The effect of somatostatin on the thyrotropin (TSH), prolactin, growth hormone (GH) and insulin responses to the combined administration of thyrotropin releasing hormone (TRH) and arginine was studied in six healthy subjects, three hypothyroid patients and three acromegalic patients. Similar inhibition by somatostatin of the TSH and insulin responses was observed in the three groups. While the tetradecapeptide had no significant effect on the prolactin response in the healthy and acromegalic subjects, it caused an unexpected inhibition of the prolactin response in two of the hypothyroid subjects. Contrary to the findings in the healthy and hypothyroid subjects, somatostatin did not inhibit the GH response in the acromegalic patients. Normal inhibition by somatostatin of the insulin response, followed by a rebound in insulin secretion, was observed in all subjects. These preliminary data indicate increased sensitivity of the prolactin-secreting cells to somatostatin in hypothyroidism and suggest that decreased responsiveness of the somatotrophs to somatostatin could play a role in the pathogenesis of acromegaly.     

贝科能对心肺复苏后大鼠心、脑、肾的保护作用

目的:研究贝科能(复合辅酶)对心肺复苏大鼠心、脑、肾的保护作用.方法:SD大鼠24只,采用窒息合并冰氯化钾停跳液致大鼠心跳骤停5 min后开始心肺复苏的动物模型,随机分为对照组(仅行假手术)、常规复苏组和贝科能治疗组,每组8只.复苏后24 h采取组织标本,采用比色法测定心、脑、肾组织中丙二醛(MDA)含量及超氧化物歧化酶(SOD)、Na -K - ATPase活力,采用透射电镜观察心、脑、肾细胞超微结构.结果:常规复苏组与对照组相比,心、脑、肾组织中MDA含量明显增高,SOD及Na -K -ATPase活力显著降低(P<0.05);贝科能治疗组各项指标检测均比常规复苏组好(P<0.05).透射电镜下可见对照组大鼠心、脑、肾细胞超微结构形态正常,常规复苏组各器官细胞线粒体肿胀、嵴断裂、空泡变性,贝科能治疗组细胞超微结构改变较轻.结论:贝科能对心肺复苏大鼠的心、脑、肾细胞具有保护作用.     

Prevalence of diabetes among hypothyroid subjects

Thyroid dysfunction affects a significant portion of the general population. Most studies have found a higher prevalence of hypothyroidism in women, increasing with age. Prevalence of hyperthyroidism has been found to range 0.5-3.0%. Type 2 diabetes is a major public health problem affecting approximately 4.8 percent of the Bangladeshi population. The study was designed to see the prevalence of type 2 diabetes in hypothyroid patients of any etiology. Four hundred forty two consecutive cases of diagnosed hypothyroidism were recruited in the study. All diagnosed hypothyroid subjects (sub-clinical or overt) reported in one year not known to be diabetic previously, underwent standard OGTT (FPG and 2-hour post 75 gram glucose) before initiation of thyroid hormone replacement. Newly detected diabetes among the subjects diagnosed as hypothyroidism is significantly higher 4.8 vs. 7.01% (p<0.01) and the prevalence of pre-diabetic state Impaired Glucose Tolerance (IGT) is also higher (11% vs. 12.6%) among hypothyroid subjects. Pure IFG (FPG ≥6.1 mmol/l but <7.0 mmol/l, and 2-PG <7.8 mmol/l) was found in 5.2% according to WHO criteria and the prevalence is higher (6.8%) with ADA criteria (considering normal FBG <5.6mmol/l). Diabetes was found in 7.01% among hypothyroid subjects which is higher than the existing known prevalence (4.8%). IGT was also found higher among hypothyroid subjects than population prevalence (8.6%). Further larger sample study is essential to establish the findings.     

口服低剂量混合稀土“常乐”对糖尿病大鼠肾脏损伤的修复作用

目的：通过探讨口服低剂量混合稀土“常乐”对糖尿病大鼠肾脏形态结构的影响,阐明其对糖尿病大鼠肾脏损伤的修复作用。方法：Wistar雄性大鼠制备糖尿病大鼠模型,造模成功的大鼠分为糖尿病模型组（10只）和“常乐”给药组（10只）,另取10只正常大鼠作为对照组,3组大鼠分别每日给予生理盐水、“常乐”（0.2 mg?kg-1）灌胃1个月,处死取肾脏,采用形态计量技术检测各组大鼠肾脏的质量、体质量、肾质量与体质量比、肾皮质厚度、肾小球体密度、肾小球总体积、近（远）端小管总体积、近（远）端小管上皮细胞高度、近（远）端小管管腔直径及肾脏的形态学。结果：与对照组和“常乐”给药组比较,糖尿病模型组肾脏质量明显增加（P<0.01）、体质量明显减轻（P<0.01）、肾质量与体质量比明显升高（P<0.01）、肾小球总体积明显增大（P<0.01）、近（远）端小管总体积明显增大（P<0.01）、近端小管上皮细胞高度明显增高（P<0.01）、近（远）端小管管腔直径明显增大（P<0.01）、肾皮质厚度和肾小球体积及远端小管上皮细胞高度无变化（P>0.05）;与对照组比较,“常乐”给药组大鼠肾脏的质量、肾皮质厚度、肾小球体密度、肾小球总体积、近端小管总体积、近（远）端小管上皮细胞高度、近（远）端小管管腔直径均无明显变化（P>0.05）,体质量明显减轻（P<0.01）,肾质量与体质量比明显增加（P<0.01）,远端小管总体积明显增加（P<0.01）。HE染色,对照组大鼠肾脏未见异常;糖尿病模型组大鼠肾脏肿胀,见大量炎细胞浸润。PAS染色,糖尿病模型组大鼠大部分近端小管上皮细胞明显肿胀,含PAS阳性物质增多,有少数近端小管可见上皮细胞脱落和管腔扩张,远端小管部分扩张,但上皮细胞无明显改变;“常乐”给药组大鼠近端小管上皮细胞略微肿胀,少量PAS阳性物质,无近端小管上皮细胞脱落和管腔扩张及远端小管扩张。结论：口服低剂量混合稀土“常乐”对糖尿病大鼠肾脏损伤具有修复作用。     

Relevance of increased serum thyroxine concentrations associated with normal serum triiodothyronine values in hypothyroid patients receiving thyroxine: a case for "tissue thyrotoxicosis"

Fifteen patients receiving standard thyroxine replacement therapy (100-200 micrograms daily) for primary hypothyroidism and who had persistently raised free thyroxine concentrations in their serum were investigated to see whether the dose being given was too high. In addition to the usual thyroid hormone assays systolic time intervals (which indicate left ventricular contractility) were calculated as accurate reflectors of tissue thyroid activity. All patients showed the expected increased free and total thyroxine concentrations; but mean total and free concentrations of triiodothyronine were normal, while reverse triiodothyronine values were raised. Mean systolic time intervals were significantly reduced as compared with normal and fell within the thyrotoxic range. Seven patients subsequently had their doses of thyroxine reduced by 50 micrograms daily and were reinvestigated one month later. All showed significant falls in circulating thyroxine and triiodothyronine concentrations and an increase in mean systolic time intervals to the normal range. In patients receiving thyroxine replacement therapy for primary hypothyroidism a raised serum thyroxine concentration may indicate tissue thyrotoxicosis and should prompt a reduction of the thyroxine dose.     

围生期甲状腺功能低下大鼠海马神经元凋亡机制研究

目的:探讨甲状腺功能低下(简称甲低)发育期大鼠海马神经元凋亡途径.方法:孕15 d SD大鼠丙基硫氧嘧啶(50 mg/d)灌胃造成仔鼠甲低动物模型.采用化学发光法测定1、5、10、15日龄仔鼠血清FT3及FT 4水平.应用透射电镜观察10日龄仔鼠海马神经元线粒体超微结构.Western Blottin g检测各日龄海马神经元胞浆及线粒体中Bax、细胞色素C与AIF基因以及胞浆中caspase-3活性片段P20蛋白表达的变化.结果:模型仔鼠各日龄血清FT4水平始终接近于药盒检测限(2.8 pmol/L),明显低于对照仔鼠(1、5日龄均P<0.01;10、15日龄均P<0.001);血清FT3较同日龄对照仔鼠降低(1日龄P<0.05;其它日龄均P<0.01).模型仔鼠形态改变的线粒体与对照相比明显增多(分别为57%和19%) . 与同日龄正常仔鼠比较,甲低仔鼠胞浆中Bax表达增加(均P<0.05),线粒体中Bax表达增加非常显著(均P<0.001);甲低仔鼠胞浆中细胞色素C表达增加(1、10、15日龄均 P<0.05,5日龄 P<0.001),线粒体中表达下降(均P<0.05);甲低仔鼠胞浆中AIF表达增加(均P<0.001),线粒体中表达下降(1、5日龄均P<0.001,10、15 日龄均P<0.01);甲低仔鼠caspase-3 P20表达明显增加(1、15日龄均P<0.01; 5、10日龄均P<0.001).结论:甲低发育期大鼠海马神经元凋亡可能通过线粒体凋亡途径介导.