Maran R R, Senthilkumaran B, Udhayakumar R C, Arunakaran J, Aruldhas M M
Department of Endocrinology, Dr ALM P.G. Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai 600 113, India.
Int J Androl. 2000 Jun;23(3):156-62. doi: 10.1046/j.1365-2605.2000.00220.x.
Earlier studies have shown that thyroid hormones play an important role in glycoprotein metabolism in the prostate. In this paper, hypothyroidism induced changes in prostatic glycoprotein-associated monosaccharides and fructose concentrations were studied in 30-day-old peripubertal rats. Hypothyroidism was induced by total surgical thyroidectomy and confirmed by radioimmunoassay (RIA) of thyroid hormones and thyroid stimulating hormone (TSH). Animals were killed after 30 and 60 days post-thyroidectomy. To test the direct effect of thyroid hormones on prostatic monosaccharides, prostatic tissue was incubated for 24 h at 37 degrees C with 25, 50 or 100 ng/mL T3. Ventral prostatic hexosamines and sialic acid concentrations were significantly decreased in hypothyroid rats aged 30 and 60 days, whereas fucose concentration was increased at 30 days but decreased at 60 days in hypothyroid rats. In the case of the dorsolateral prostate, hypothyroidism enhanced the concentration of hexosamines but caused a decrease in levels of fucose, sialic acid and fructose, irrespective of the duration of hypothyroidism. Concentrations of fucose, fructose and hexosamines in the anterior prostate were decreased and sialic acid concentration was increased in 60-day hypothyroid rats. In in vitro studies, the concentrations of fucose, sialic acid and hexosamines were significantly increased in all three prostatic lobes irrespective of the T3 dose with which they had been incubated. A consistent increase in fructose concentration was observed in anterior and dorsolateral prostates when incubated with different doses of T3 stimulation. It is concluded that the influence of hypothyroidism on prostatic monosaccharides seems to be specific for each sugar in different lobes of the prostate. These results clearly show that thyroid hormones differentially regulate prostatic glycoprotein metabolism.
早期研究表明，甲状腺激素在前列腺糖蛋白代谢中起重要作用。在本文中，对30日龄青春期前大鼠进行了甲状腺功能减退诱导的前列腺糖蛋白相关单糖和果糖浓度变化的研究。通过全甲状腺切除术诱导甲状腺功能减退，并通过甲状腺激素和促甲状腺激素（TSH）的放射免疫测定（RIA）进行确认。在甲状腺切除术后30天和60天处死动物。为了测试甲状腺激素对前列腺单糖的直接作用，将前列腺组织在37℃下与25、50或100 ng/mL T3孵育24小时。30日龄和60日龄甲状腺功能减退大鼠的腹侧前列腺己糖胺和唾液酸浓度显著降低，而甲状腺功能减退大鼠在30天时岩藻糖浓度升高，但在60天时降低。在背外侧前列腺中，无论甲状腺功能减退的持续时间如何，甲状腺功能减退都会提高己糖胺的浓度，但会导致岩藻糖、唾液酸和果糖水平降低。60日龄甲状腺功能减退大鼠的前叶前列腺中岩藻糖、果糖和己糖胺的浓度降低，唾液酸浓度升高。在体外研究中，无论孵育时使用的T3剂量如何，所有三个前列腺叶中岩藻糖、唾液酸和己糖胺的浓度均显著增加。当用不同剂量的T3刺激孵育时，在前叶和背外侧前列腺中观察到果糖浓度持续增加。结论是，甲状腺功能减退对前列腺单糖的影响似乎对前列腺不同叶中的每种糖具有特异性。这些结果清楚地表明，甲状腺激素对前列腺糖蛋白代谢有不同的调节作用。
