Chertow B S, Williams G A, Norris R M, Baker G R, Hargis G K
Eur J Clin Invest. 1977 Aug;7(4):307-14. doi: 10.1111/j.1365-2362.1977.tb01610.x.
The effect of vitamin A, a membrane surface-active agent, on parathyroid hormone secretion was studied in vitro, using bovine parathyroid tissue, and in vivo in man. Parathyroid tissues were incubated with vitamin A (retinol), retinoic acid, and calcium, and with hydrocortisone and vitamin E, agents that antagonize the membrane effects of vitamin A. The stimulation of parathyroid hormone release by vitamin A, 10(-6) to 10(-9) mol/1 in vitro, was dose and time dependent. Retinoic acid did not stimulate secretion. High calcium concentration, hydrocortisone, 10(-5) mol/1 and 10(-6) mol/1, and vitamin E, 10(-5) mol/1, antagonized vitamin A-induced parathyroid hormone secretion. Vitamin A increased the lysosomal cathepsin D activity of parathyroid tissues. In human studies, eleven healthy men received two intramuscular injections of vitamin A palmitate, 25 000 units each, within 24 h. In every subject, serum parathyroid hormone increased after vitamin A administration. Our studies indicate that: (1) vitamin A stimulates parathyroid hormone secretion in vitro, possibly through modification of the cell or secretion granule membrane, or through stimulation of lysosomal proteolytic activity, and (2) vitamin A increases serum parathyroid hormone in vivo, and this effect may be important in clinical states of vitamin A excess.
利用牛甲状旁腺组织在体外以及在人体进行体内实验，研究了作为一种膜表面活性剂的维生素A对甲状旁腺激素分泌的影响。将甲状旁腺组织与维生素A（视黄醇）、视黄酸和钙一起孵育，还与氢化可的松和维生素E一起孵育，氢化可的松和维生素E是拮抗维生素A膜效应的物质。在体外，维生素A（浓度为10⁻⁶至10⁻⁹摩尔/升）对甲状旁腺激素释放的刺激呈剂量和时间依赖性。视黄酸不刺激分泌。高钙浓度、10⁻⁵摩尔/升和10⁻⁶摩尔/升的氢化可的松以及10⁻⁵摩尔/升的维生素E可拮抗维生素A诱导的甲状旁腺激素分泌。维生素A增加了甲状旁腺组织的溶酶体组织蛋白酶D活性。在人体研究中，11名健康男性在24小时内接受了两次肌肉注射，每次注射25000单位的棕榈酸视黄酯。在每个受试者中，维生素A给药后血清甲状旁腺激素均升高。我们的研究表明：（1）维生素A在体外刺激甲状旁腺激素分泌，可能是通过改变细胞或分泌颗粒膜，或通过刺激溶酶体蛋白水解活性；（2）维生素A在体内增加血清甲状旁腺激素，这种作用在维生素A过量的临床状态中可能很重要。
