Tran Ba Huy P, Ferrary E, Escoubet B, Sterkers O
Acta Otolaryngol. 1987 May-Jun;103(5-6):558-66.
Synthesis of prostaglandins (PGs) was characterized in the lateral wall (LW) of guinea-pig cochlea. Basal synthesis at 37 degrees C was about 480 pg/LW (12.8 ng X mg-1 protein) for PGI2 and 85 pg/LW (2.3 ng X mg-1 protein) for PGE2, levelling out after 10 min of incubation. Incubation with arachidonic acid (10(-5) M) increased PGI2 and PGE2 synthesis by 44% and 1020%, respectively, showing that arachidonic acid availability is a synthesis-limiting factor. The stimulating effect of the Ca++ ionophore A23187 (5 X 10(-6) M) on PG synthesis was weak (about +50%) but was enhanced (about +140%) by preincubation with arachidonic acid. Angiotensin II (10(-6) M), vasopressin (5 X 10(-7) M), and furosemide (10(-8) to 10(-3) M) did not alter PG secretion. Neither aspirin nor indomethacin prevented the development of furosemide ototoxicity (endocochlear potential) in the rat. Perfusion with PGI2 influenced the furosemide effect in some instances.
在豚鼠耳蜗外侧壁(LW)中对前列腺素(PGs)的合成进行了表征。在37℃下,PGI2的基础合成量约为480 pg/LW(12.8 ng·mg-1蛋白质),PGE2的基础合成量约为85 pg/LW(2.3 ng·mg-1蛋白质),孵育10分钟后趋于平稳。与花生四烯酸(10(-5) M)一起孵育分别使PGI2和PGE2的合成增加了44%和1020%,表明花生四烯酸的可利用性是合成的限制因素。Ca++离子载体A23187(5×10(-6) M)对PG合成的刺激作用较弱(约+50%),但在与花生四烯酸预孵育后增强(约+140%)。血管紧张素II(10(-6) M)、血管加压素(5×10(-7) M)和呋塞米(10(-8)至10(-3) M)均未改变PG分泌。阿司匹林和吲哚美辛均不能预防大鼠中呋塞米的耳毒性(内淋巴电位)的发展。在某些情况下,用PGI2灌注会影响呋塞米的作用。