Rosenberg R M, Isseroff R R, Ziboh V A, Huntley A C
J Invest Dermatol. 1986 Mar;86(3):244-8. doi: 10.1111/1523-1747.ep12285364.
Striking skin changes can accompany hypothyroidism, among them a scaly ichthyosis. The pathogenesis of these disorders is unknown. Since altered sterol metabolism has been associated with other scaling dermatoses, we tested the hypothesis that altered epidermal lipogenesis may accompany hypothyroidism and induce the observed scaling. Thyroidectomized (TX) rats were sacrificed 53 days postthyroidectomy, and the rate of incorporation of the radiolabeled precursor, [14C]acetate, into epidermal lipids was determined. Approximately 2-fold decreases in incorporation of precursor into both polar and neutral lipids were observed in the TX epidermis; the most significant decreases, however, were in the neutral lipids, particularly the sterol and sterol-ester moieties. Total cholesterol pool size was also reduced in the TX epidermis. Similar decreases in sterol biosynthesis were noted in human keratinocytes cultivated in medium devoid of thyroid hormone. These findings demonstrate that lipid metabolism, and notably sterol synthesis, is altered in epidermal keratinocytes deprived of thyroid hormone, and suggest that, as in other scaling disorders, this abnormal sterologenesis may lead to the clinically observed ichthyosis that can accompany hypothyroidism.
甲状腺功能减退症可能伴有明显的皮肤变化，其中包括鳞屑性鱼鳞病。这些病症的发病机制尚不清楚。由于固醇代谢改变与其他鳞屑性皮肤病有关，我们检验了这样一个假设，即甲状腺功能减退症可能伴有表皮脂肪生成改变，并导致观察到的鳞屑形成。甲状腺切除术后53天处死甲状腺切除（TX）大鼠，并测定放射性标记前体[14C]乙酸盐掺入表皮脂质的速率。在TX大鼠的表皮中，前体掺入极性和中性脂质的量均下降了约2倍；然而，最显著的下降发生在中性脂质中，尤其是固醇和固醇酯部分。TX大鼠表皮中的总胆固醇池大小也减小了。在缺乏甲状腺激素的培养基中培养的人角质形成细胞中也观察到固醇生物合成有类似的下降。这些发现表明，在缺乏甲状腺激素的表皮角质形成细胞中，脂质代谢，尤其是固醇合成发生了改变，这表明，与其他鳞屑性疾病一样，这种异常的固醇生成可能导致临床上观察到的可伴有甲状腺功能减退症的鱼鳞病。
