Rangachari P K, McWade D, Donoff B
Department of Medicine, McMaster University, Hamilton, Ont., Canada.
Regul Pept. 1988 Jun;21(3-4):237-44. doi: 10.1016/0167-0115(88)90006-7.
Luminal addition of bradykinin (BK) to the open-circuited canine tracheal epithelium produces a biphasic response in transmucosal potential difference (P.D.): a rapid, transient decrease (dip) followed by a subsequent, more sustained increase (rise), both phases being associated with an increase in conductance. We have attempted to characterise the receptor subtype mediating the bradykinin response. Lys-bradykinin (Lys-BK) elicited a similar response, and its EC50 as judged from concentration-response relations was similar to that of BK. Cross-tachyphylaxis between the two peptides confirmed a common receptor. Des-Arg9-BK (a B1-agonist) neither elicited a response nor inhibited responses to BK. The novel B2-antagonist [Thi6,9-D-Phe8]kallidin reversibly inhibited responses to both BK and Lys-BK. The rapid changes in P.D. (dips) were unaffected by Na+ removal, but were eliminated by replacing luminal Cl- with isethionate. Thus, BK, acting on B2-receptors, transiently increases anion permeability of the luminal membrane of the canine tracheal epithelium.
向开路状态的犬气管上皮腔内添加缓激肽（BK）会使跨粘膜电位差（P.D.）产生双相反应：先是快速、短暂的降低（下降），随后是更持久的升高（上升），两个阶段均与电导增加有关。我们试图确定介导缓激肽反应的受体亚型。赖氨酰缓激肽（Lys-BK）引发了类似的反应，根据浓度-反应关系判断，其半数有效浓度（EC50）与BK相似。两种肽之间的交叉快速耐受性证实了存在共同受体。去-精氨酸9-缓激肽（一种B1激动剂）既不引发反应，也不抑制对BK的反应。新型B2拮抗剂[噻吩6,9-二苯丙氨酸8]胰激肽可逆地抑制对BK和Lys-BK的反应。P.D.的快速变化（下降）不受去除Na+的影响，但在用羟乙基磺酸替代腔内Cl-后消除。因此，BK作用于B2受体，可短暂增加犬气管上皮腔面膜的阴离子通透性。
