van Hoek Ingrid, Daminet Sylvie
Department of Medicine & Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
Gen Comp Endocrinol. 2009 Feb 1;160(3):205-15. doi: 10.1016/j.ygcen.2008.12.008. Epub 2008 Dec 24.
Thyroidal status affects kidney function already in the embryonic stage. Thyroid hormones influence general tissue growth as well as tubular functions, electrolyte handling and neural input. Hyper- and hypo-functioning of the thyroid influences mature kidney function indirectly by affecting the cardiovascular system and the renal blood flow, and directly by affecting glomerular filtration, electrolyte pumps, the secretory and absorptive capacity of the tubuli, and the structure of the kidney. Hyperthyroidism accelerates several physiologic processes, a fact which is reflected in the decreased systemic vascular resistance, increased cardiac output (CO), increased renal blood flow (RBF), hypertrophic and hyperplastic tubuli, and increased glomerular filtration rate (GFR). Renal failure can progress due to glomerulosclerosis, proteinuria and oxidative stress. Hypothyroidism has a more negative influence on kidney function. Peripheral vascular resistance is increased with intrarenal vasoconstriction, and CO is decreased, causing decreased RBF. The influence on the different tubular functions is modest, although the transport capacity is below normal. The GFR is decreased up to 40% in hypothyroid humans. Despite the negative influences on glomerular and tubular kidney function, a hypothyroid state has been described as beneficial in kidney disease. Kidney disease is associated with decreased thyroid hormone concentrations caused by central effects and by changes in peripheral hormone metabolism and thyroid hormone binding proteins. Geriatric cats form an animal model of disease because both hyperthyroidism and chronic kidney disease (CKD) have high prevalence among them, and the link between thyroid and kidney affects the evaluation of clinical wellbeing and the possible treatment options.
甲状腺状态在胚胎期就会影响肾功能。甲状腺激素影响全身组织生长以及肾小管功能、电解质处理和神经输入。甲状腺功能亢进和减退通过影响心血管系统和肾血流量间接影响成熟肾功能，也通过影响肾小球滤过、电解质泵、肾小管的分泌和吸收能力以及肾脏结构直接影响肾功能。甲状腺功能亢进会加速多个生理过程，这体现在全身血管阻力降低、心输出量（CO）增加、肾血流量（RBF）增加、肾小管肥大和增生以及肾小球滤过率（GFR）增加。肾衰竭可能因肾小球硬化、蛋白尿和氧化应激而进展。甲状腺功能减退对肾功能有更负面的影响。外周血管阻力增加，肾内血管收缩，心输出量降低，导致肾血流量减少。尽管转运能力低于正常水平，但对不同肾小管功能的影响较小。甲状腺功能减退的人肾小球滤过率降低高达40%。尽管对肾小球和肾小管肾功能有负面影响，但甲状腺功能减退状态在肾脏疾病中被描述为有益。肾脏疾病与中枢效应以及外周激素代谢和甲状腺激素结合蛋白变化导致的甲状腺激素浓度降低有关。老年猫形成了一种疾病动物模型，因为甲状腺功能亢进和慢性肾病（CKD）在它们当中都有很高的患病率，并且甲状腺与肾脏之间的联系会影响临床健康评估和可能的治疗选择。
