Pourageaud F, Freslon J L
Laboratoire de Pharmacodynamie, Faculté de Pharmacie, Bordeaux, France.
Fundam Clin Pharmacol. 1995;9(1):37-45. doi: 10.1111/j.1472-8206.1995.tb00263.x.
To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15-25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D100) were determined and vessels were set up to a normalized internal diameter (0.9 D100). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 microM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 microM) but not D-arginine (100 microM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 microM] in MRA; serotonin, 5-HT [10 microM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 microM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 microM) completely inhibited relaxations induced by acetylcholine (0.01-10 microM) in all types of precontracted arteries.(ABSTRACT TRUNCATED AT 250 WORDS)
为研究在自发性高血压大鼠（SHR）阻力动脉中观察到的功能改变在冠状动脉水平是否也存在，对15 - 25周龄的SHR和年龄匹配的Wistar Kyoto大鼠（WKY）的肠系膜阻力动脉（MRA）、右冠状动脉（RIC）和左心室冠状动脉（LIC）进行了体外实验。采用被动伸展方案，测定对应于100 mmHg腔内压力的内径（D100），并将血管设定为标准化内径（0.9 D100）。与WKY动脉相比，SHR肠系膜阻力动脉的直径明显更小，而两种类型的SHR冠状动脉的直径均比WKY大鼠的大。在没有收缩激动剂的动脉中，硝基-L-精氨酸（NOLA，100 μM）可使基础张力逐渐升高，随后添加L-精氨酸（100 μM）可使其逆转，但添加D-精氨酸（100 μM）则不能。当以激动剂诱导的最大收缩百分比表示时（MRA中为去甲肾上腺素，NA [10 μM]；RIC和LIC中为5-羟色胺，5-HT [10 μM]），与SHR冠状动脉和肠系膜阻力动脉相比，WKY中的这些收缩明显更强。在存在吲哚美辛（10 μM）的情况下，NA预收缩的MRA和5-HT预收缩的冠状动脉中，乙酰胆碱诱导的最大舒张幅度（以激动剂诱导的最大收缩百分比表示）在WKY中比SHR动脉更大。孵育30分钟后，NOLA（100 μM）完全抑制了所有类型预收缩动脉中乙酰胆碱（0.01 - 10 μM）诱导的舒张。（摘要截短至250字）
