Beinborn M, Nüstedt V, Sewing K F
Abteilung Allgemeine Pharmakologie, Medizinische Hochschule Hannover, FRG.
Scand J Gastroenterol Suppl. 1989;164:21-4; discussion 24-5. doi: 10.3109/00365528909091181.
The interaction of rioprostil with the porcine parietal cell prostaglandin (PG) E2 receptor and with uterine 3H-PGE2 binding sites was investigated. The in vitro antisecretory effect was measured by the inhibition of histamine stimulated 14C-aminopyrine uptake in isolated pig parietal cells. Rioprostil displaced 3H-PGE2 competitively from the porcine fundic PGE2 receptor and had 1/25 of the affinity (Kd = 8 X 10(-8) mol/l) of the natural ligand; it was, however, equipotent with the synthetic prostacyclin analogue, iloprost. Similar affinity ratios were found in uterine muscle. Rioprostil inhibits parietal cell acid production with an IC50 in the range of its gastric binding dissociation constant. It is concluded that rioprostil exerts its antisecretory effects via a parietal cell E-type receptor. The compound cannot discriminate between fundic and uterine 3H-PGE2 binding sites with as yet unknown functional implications.
研究了利奥前列素与猪壁细胞前列腺素（PG）E2受体以及子宫3H-PGE2结合位点的相互作用。通过抑制组胺刺激的离体猪壁细胞中14C-氨基比林摄取来测定体外抗分泌作用。利奥前列素从猪胃底PGE2受体上竞争性取代3H-PGE2，其亲和力（Kd = 8×10(-8) mol/l）为天然配体的1/25；然而，它与合成前列环素类似物伊洛前列素具有同等效力。在子宫肌中也发现了类似的亲和力比值。利奥前列素抑制壁细胞产酸，其IC50在其胃结合解离常数范围内。得出的结论是，利奥前列素通过壁细胞E型受体发挥其抗分泌作用。该化合物无法区分胃底和子宫的3H-PGE2结合位点，其功能意义尚不清楚。
