ARACHIDONIC-ACID METABOLITES AND CHLORIDE SECRETION IN RABBIT DISTAL COLONIC MUCOSA

被引:49
作者
CALDERARO, V [1 ]
GIOVANE, A [1 ]
DESIMONE, B [1 ]
CAMUSSI, G [1 ]
ROSSIELLO, R [1 ]
QUAGLIUOLO, L [1 ]
SERVILLO, L [1 ]
TACCONE, W [1 ]
GIORDANO, C [1 ]
BALESTRIERI, C [1 ]
机构
[1] NAPLES UNIV,INST PATHOL,I-80138 NAPLES,ITALY
来源
AMERICAN JOURNAL OF PHYSIOLOGY | 1991年 / 261卷 / 03期
关键词
PROSTAGLANDINS; 5-HYDROXY-6,8,11,14-EICOSATETRAENOIC ACID;
D O I
10.1152/ajpgi.1991.261.3.G443
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
The relationships between arachidonic acid (AA) metabolism and chloride secretion were investigated in mucosal preparations of rabbit distal colon. Tissues displayed a significant cyclooxygenenase activity already in nonstimulated conditions and incubation with exogenous AA and calcium ionophore A23187 produced a predominant prostaglandin F2-alpha (PGF2-alpha) profile [PGF2-alpha > PGE2 > thromboxane B2 (TxB2) > 6-keto-PGF1-alpha] as assessed by HPLC of tissue homogenates, whereas 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE) was not detected in AA- or A23187-stimulated tissues. Radioimmunological assays showed that PGE2 synthesis was time dependent, plateaued at 10 min, and proceeded at rates 15-20 times over TxB2 and 6-keto-PGF1-alpha. Among the PGs produced by colonic mucosa, only PGE2 and, to a lower extent, PGF2-alpha, were found to stimulate chloride secretion and cAMP synthesis. Pretreatment with 10-mu-M 5,8,11,14-eicosatetraynoic acid, a cyclo- and lipoxygenase inhibitor, prevented AA-induced chloride secretion and PG and cAMP synthesis with the same strength as the cyclooxygenase inhibitor indomethacin. No effects were found after preincubation with nordihydroguaiaretic acid, a lipoxygenase blocker with moderate cyclooxygenase inhibitory properties, and caffeic acid, a lipoxygenase inhibitor. 5-HETE (5-mu-M) had no effect on short-circuit currents (I(sc)) and chloride transport, but it significantly reduced the increase in I(sc), chloride secretion, and PGE2 synthesis elicited by AA or A23187. Platelet-activating factor, reported to stimulate rabbit colon I(sc) through an indomethacin-sensitive pathway, was not detected at concentrations as low as 10(-10) M.
引用
收藏
页码:G443 / G450
页数:8
相关论文
共 35 条