Effects of experimental hypo- and hyperthyroidism on iodothyronine deiodinases in Nile tilapia, Oreochromis niloticus

In the present study, we examined the effects of experimentally-induced increases or decreases in plasma concentrations of thyroid hormones on iodothyronine deiodinases in tilapia, Oreochromis niloticus. To obtain hyperthyroid tilapia, fish were injected with porcine follicle stimulating hormone (pFSH) 36 hours before sampling or fed on demand for 11 days with tilapia pellets containing 12 ppm T3. Tilapias were made hypothyroid by providing them food containing 0.2% methimazole for 11 days. Plasma T4 and T3 and the in vitro deiodinase activity in liver, kidney, brain and gill were measured at the end of the treatment period. Injection with pFSH caused an increase in plasma T4 but had no influence on plasma T3 levels. A small increase in plasma T3 was observed in T3-fed fish. Plasma levels of both T4 and T3 were decreased by methimazole treatment. We observed no changes in kidney type I deiodinase (D1), whereas liver type II deiodinase (D2) was increased during hypothyroidism and decreased during hyperthyroidism. Hypothyroidism resulted in a significant decrease in brain, gill and liver type III deiodinase (D3). An pFSH-induced increase in T4 stimulated brain and gill D3 but not liver D3, whereas the opposite was true in T3-fed fish. We conclude that the regulation of D1 and D3 in tilapia is probably different compared to mammals.     

Congenital hypothyroidism and dysmaturity syndrome in foals: First reported cases in Europe

Congenital hypothyroidism and dysmaturity syndrome (CHD) in neonatal foals was first described in western Canada in 1981 and remains an important problem for the western Canadian horse industry. This syndrome is characterised by hyperplasia of the thyroid gland, increased gestational length and multiple congenital musculoskeletal abnormalities. This case series describes the first confirmed cases of CHD in Europe and challenges contemporary opinion which suggests that this syndrome is distinct from congenital hypothyroidism associated with visible goitre.     

Occurrence of autoantibodies against thyroglobulin in Norwegian dogs

Serum samples from 45 hypothyroid dogs, 11 clinically healthy dogs and 31 dogs with various clinical endocrinopathies, seborrhoea and dermatitis were tested for thyroglobulin antibodies using the passive hemagglutination test. A chromic chloride (CCH)- and a glutaraldehyde (GCH) method were used in the assay. Circulating antibody titer against thyroglobulin were observed in 34 % and 24 % of dogs with hypothyroidism by the CCH and the GCH method, respectively. Three of 12 dogs with seborrhoea had low titers (20 to 40) of thyroglobulin antibodies. Thyroglobulin antibodies were observed in 1 of 3 hypothyroid dogs with thyroid carcinoma. Clinically healthy dogs and dogs with certain other endocrinopathies (Addison’s disease, Cushing’s disease, Diabetes mellitus, Hyperestrogenism) and dermatitis were negative.Though the CCH method detected thyroglobulin antibodies in more serum samples than the GCH method, the GCH method was considered more reliable in that the glutaraldehyde treated cells were more stable, both at room temperature and at +4°C.     

Hypothalamic-pituitary axis deficiency following traumatic brain injury in a dog

Objective – To describe endocrine dysfunction associated with traumatic brain injury in a dog.
Summary – A 12-week-old dog presented with traumatic brain injury and did not respond to traditional supportive care. Continued hypothermia, electrolyte derangements, hypotension, and hyposthenuria prompted screening for and detection of several hypothalamic-pituitary disorders including: hypoadrenocorticism, central diabetes insipidus, hypothyroidism, and growth hormone deficiency. Electrolyte abnormalities, urine osmolarity, and blood pressure improved with treatment for the associated disorders.
New or Unique Information Provided – This is the first report of generalized hypothalamic-pituitary dysfunction or panhypopituitarism following traumatic brain injury in a dog.     

碘与酒精阳性乳相关性的探讨

当前我国奶牛业发展很快 ,而因奶牛酒精阳性乳的发生造成乳的废弃使奶牛业损失很大。目前 ,奶牛酒精阳性乳的发生原理还不清楚 ,本试验力图探讨其发生原理。试验通过对酒精试验 ,乳脂率 ,导电率及酸度值的测定发现 ,奶牛酒精阳性乳的发生率与气候变化有密切关系 ,酒精阳性牛乳的乳脂率高于正常乳 0 .3～0 .5个百分点 (p <0 .0 5)。给酒精阳性乳奶牛投服自制补碘丸剂 ,治愈疗效高达 80 %以上 ,提示酒精阳性乳的发生与甲状腺功能降低有关。我们认为 :奶牛酒精阳性乳的发生主要归因于甲状腺功能低下 ,通过适当补碘提高甲状腺功能 ,促进甲状腺素的分泌 ,维持正常乳腺功能     

亚临床甲状腺功能减退症动物模型研究进展

亚临床甲状腺功能减退症(SCH)是一种发病率较高的隐匿性甲状腺疾病,其发病率比临床甲状腺功能减退症高得多。目前,国内外就SCH的研究主要侧重于临床和人群的流行病学调查,较少涉及动物及相关机制研究。动物模型的建立是相关机制研究的基础,建立良好的SCH的动物模型,对于其机制研究意义重大。论文通过国内外SCH动物造模方法的比较,探讨其异同和优缺点,为相关研究提供参考。     

不同甲状腺功能状态患者血浆B型钠尿肽的检测及其临床意义

目的 了解不同甲状腺功能状态患者血浆B型钠尿肽浓度及B型钠尿肽与血浆FT3、FT4的关系.方法 采用酶联免疫法(ELISA)检测72例甲状腺功能亢进和60例甲状腺功能减退症患者血浆B型钠尿肽(BNP)水平.结果 血浆FT3、FT4、BNP甲亢未治组高于甲亢缓解组和对照组,差异有统计学意义(P＜0.01);甲亢缓解组与对照组比较,差异无统计学意义(P＞0.05).血浆FT3、FT4甲减未治组低于甲减治疗组和对照组,差异有统计学意义(P＜0.01);甲减治疗组与对照组比较,差异无统计学意义(P＞0.05);但甲减未治组、甲减治疗组和对照组BNP比较,差异均无统计学意义(P＞0.05).甲亢未治组患者血浆BNP与FT3、FT4两者呈量依赖关系,r分别为0.9919和0.9999996(均P＜0.01),回归方程分别为y=193.8 3.191x,y=198.0 0.8353x.结论 BNP对甲亢的辅助诊断和疗效观察具有一定临床价值.     

The effect of experimentally induced hypothyroidism on the isoflurane minimum alveolar concentration in dogs

ObjectiveTo determine the effect of experimentally induced hypothyroidism on isoflurane (ISO) minimum alveolar concentration (MAC) in dogs.Study designProspective experimental study.AnimalsEighteen adult female mongrel dogs, age 2–4 years and weighing 8.2–13.1 kg.MethodsHypothyroidism was induced in nine dogs by the intravenous administration of 1 mCi kg⁻¹ of ¹³¹Iodine. The remaining nine dogs served as controls. Dogs were studied 9–12 months after the induction of hypothyroidism. Anesthesia was induced with ISO in oxygen via a mask. The trachea was intubated, and anesthesia was maintained using ISO in oxygen using a semi-closed rebreathing circle system. The dogs were mechanically ventilated to maintain an end-tidal carbon dioxide concentration between 35 and 45 mmHg. End-tidal ISO concentrations were measured with an infrared gas analyzer. The MAC was determined in duplicate using a tail clamp technique. The mean values for the groups were compared using a two sample t-test.ResultsThe mean ± SD MAC of isoflurane in the hypothyroid and euthyroid dogs was 0.98 ± 0.31% and 1.11 ± 0.26%, respectively. The mean MAC of isoflurane in hypothyroid dogs was not significantly different from the mean MAC of isoflurane in the control dogs (p=0.3553).Conclusion and clinical relevanceThe MAC of ISO in dogs was not significantly affected by experimentally induced hypothyroidism. The dose of ISO in dogs with hypothyroidism does not need to be altered.