Takahashi K, Suda K, Lam H C, Ghatei M A, Bloom S R
Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London.
J Endocrinol. 1991 Jul;130(1):123-7. doi: 10.1677/joe.0.1300123.
The factors associated with high concentrations of circulating plasma immunoreactive endothelin in patients with diabetes mellitus are unknown. Plasma and tissue (lung and kidney) immunoreactive endothelin levels were therefore measured by radioimmunoassay in three animal models of diabetes mellitus: dexamethasone-treated rats (2 mg/kg per day for 12 days), streptozotocin-treated rats (100 mg/kg, 4 days before being killed) and rats treated with both dexamethasone and streptozotocin. Plasma concentrations of immunoreactive endothelin in the dexamethasone-treated rats (3.13 +/- 0.28 pmol/l, mean +/- S.E.M., n = 15) were significantly (P less than 0.005) higher than those in controls (1.33 +/- 0.18 pmol/l, n = 15), while plasma concentrations of immunoreactive endothelin in streptozotocin-treated rats (n = 8) and rats treated with both dexamethasone and streptozotocin (n = 14) were undetectable (less than 0.5 pmol/l). Fast protein liquid chromatographic analysis of the plasma immunoreactive endothelin of dexamethasone-treated rats showed four peaks: one in the void volume, one eluting before endothelin-3, one eluting after endothelin-3 and before endothelin-1 and one eluting in a position identical with that of endothelin-1. Pulmonary concentrations of immunoreactive endothelin in the three groups of rats with diabetes mellitus were lower (P less than 0.005) but no significant change was found in renal immunoreactive endothelin. These findings indicate that short-term dexamethasone treatment increases plasma levels of immunoreactive endothelin while streptozotocin treatment decreases them. Thus, multiple factors may influence plasma concentrations of immunoreactive endothelin in diabetes mellitus.
糖尿病患者循环血浆中免疫反应性内皮素浓度升高的相关因素尚不清楚。因此，通过放射免疫分析法测定了三种糖尿病动物模型的血浆和组织（肺和肾）免疫反应性内皮素水平：地塞米松处理的大鼠（每天2 mg/kg，共12天）、链脲佐菌素处理的大鼠（100 mg/kg，处死前4天）以及同时用地塞米松和链脲佐菌素处理的大鼠。地塞米松处理的大鼠血浆免疫反应性内皮素浓度（3.13±0.28 pmol/l，均值±标准误，n = 15）显著高于对照组（1.33±0.18 pmol/l，n = 15）（P<0.005），而链脲佐菌素处理的大鼠（n = 8）和同时用地塞米松和链脲佐菌素处理的大鼠（n = 14）的血浆免疫反应性内皮素浓度未检测到（低于0.5 pmol/l）。地塞米松处理的大鼠血浆免疫反应性内皮素的快速蛋白质液相色谱分析显示有四个峰：一个在空体积处，一个在内皮素-3之前洗脱，一个在内皮素-3之后且在内皮素-1之前洗脱，一个在内皮素-1相同位置洗脱。三组糖尿病大鼠的肺组织免疫反应性内皮素浓度较低（P<0.005），但肾组织免疫反应性内皮素无显著变化。这些发现表明，短期地塞米松治疗可增加血浆免疫反应性内皮素水平，而链脲佐菌素治疗则降低其水平。因此，多种因素可能影响糖尿病患者血浆免疫反应性内皮素的浓度。
