Biancani P, Walsh J H, Behar J
J Clin Invest. 1984 Apr;73(4):963-7. doi: 10.1172/JCI111320.
The effect of rabbit vasoactive intestinal polypeptide (VIP) antiserum on in vitro relaxation of the lower esophageal sphincter (LES) was studied in 10 cats. The stomach and esophagus were opened along the lesser curvature of the stomach and stripped of mucosa. Consecutive strips were cut and mounted in a 2.5-ml muscle chamber. They were perfused with Tyrode's solution and oxygenated continuously. After equilibration for 1 h, perfusion was stopped and one strip from the lower esophageal sphincter region was incubated in solution that contained 12-25 parts of VIP antiserum per 1,000 to Tyrode's solution, while a second strip was incubated in a solution of normal rabbit serum at the same concentration. A third strip was maintained in Tyrode's solution for the duration of the experiment. After a 1-h incubation, the strips were stimulated with 6-s square wave trains of 0.1-, 0.2-, 0.4-, and 0.8-ms pulses at 1, 2, and 5 Hz. These stimulation parameters produced LES relaxation that was completely blocked by tetrodotoxin but not by atropine or phentolamine. The strips incubated in Tyrode's solution or in normal serum relaxed reliably and consistently at all levels of stimulation. In the antiserum-treated strips, LES relaxation in response to all stimuli was significantly inhibited. Strips treated with normal serum were relaxed in a dose-dependent fashion by 10(-7) and 10(-6) M VIP, whereas the antiserum inhibited the relaxation induced by 10(-7) M, but not by 10(-6) M, VIP. Stimulation with two successive 15-min trains of electrical pulses (2 ms, 5 Hz) separated by 30 min of rest released increasing amounts of VIP into the bathing solution. VIP released during the second train of electrical stimulation was significantly (P less than 0.05) greater than in control conditions. In the cat LES, VIP antiserum inhibits the relaxation induced by exogenous VIP or by electric stimulation of nonadrenergic, noncholinergic inhibitory nerves at a level that causes the release of VIP. These findings are consistent with the hypothesis that VIP may be an inhibitory neurotransmitter responsible for LES relaxation.
在10只猫身上研究了兔血管活性肠肽（VIP）抗血清对离体食管下括约肌（LES）舒张的影响。沿胃小弯打开胃和食管，去除黏膜。将连续的组织条剪下并安装在一个2.5毫升的肌肉槽中。用台氏液灌注并持续供氧。平衡1小时后，停止灌注，将一条取自食管下括约肌区域的组织条放在每1000份台氏液中含12 - 25份VIP抗血清的溶液中孵育，而另一条组织条在相同浓度的正常兔血清溶液中孵育。第三条组织条在整个实验过程中保持在台氏液中。孵育1小时后，用1、2和5赫兹的0.1 -、0.2 -、0.4 -和0.8毫秒脉冲的6秒方波串刺激组织条。这些刺激参数产生的LES舒张完全被河豚毒素阻断，但不被阿托品或酚妥拉明阻断。在台氏液或正常血清中孵育的组织条在所有刺激水平下都能可靠且持续地舒张。在抗血清处理的组织条中，对所有刺激的LES舒张均受到显著抑制。用正常血清处理的组织条对10⁻⁷和10⁻⁶摩尔/升的VIP呈剂量依赖性舒张，而抗血清抑制10⁻⁷摩尔/升VIP诱导的舒张，但不抑制10⁻⁶摩尔/升VIP诱导的舒张。用两个连续的15分钟电脉冲串（2毫秒，5赫兹）刺激，中间休息30分钟，会使越来越多的VIP释放到浴液中。第二次电刺激串期间释放的VIP显著（P小于0.05）多于对照条件下。在猫的LES中，VIP抗血清在导致VIP释放的水平上抑制外源性VIP或非肾上腺素能、非胆碱能抑制神经电刺激诱导的舒张。这些发现与VIP可能是负责LES舒张的抑制性神经递质这一假说一致。
