Denniss A R, Young J A
Pflugers Arch. 1978 Aug 25;376(1):73-80. doi: 10.1007/BF00585250.
The effects of various polypeptide enterohormones and the tachykinin secretogogue, physalaemin, on electrolyte transport by the main excretory duct of the mandibular gland of the rabbit were studied in vitro. Vasoactive intestinal peptide (VIP, 2 X 10(-11) mol 1(-1)) and gastric inhibitory polypeptide (GIP, 10(-11) mol 1(-1)) reduced nett Na+ movement from lumen to interstitium and VIP also reduced the transepithelial potential difference; the effective concentrations of the two hormones lay within the range of normal plasma concentrations. Gastrin (5 x 10(-7) mol 1(-1)) and synthetic secretin (2 x 10(-7) mol 1(-1)) had similar effects but only at concentrations well above the normal plasma levels. Caerulein, an analogue of the octapeptide of cholecystokinin, had no effect on duct function even at a concentration of 10(-6) mol 1(-1). The potent salivary secretogogue, physalaemin (4 x 10(-8) mol 1(-1)), which is an analogue of Substance P, a putative mammalian enterohormone and neurotransmitter substance, caused a marked increase in ductal Na transport (in rat as well as rabbit). It is concluded that VIP and GIP would normally play a role in determining salivary electrolyte composition and it is postulated that their action may be antagonized by a tachykinin such as Substance P.
在体外研究了各种多肽肠激素和速激肽分泌促进剂——雨蛙肽对兔下颌腺主排泄管电解质转运的影响。血管活性肠肽（VIP，2×10⁻¹¹摩尔/升）和胃抑制多肽（GIP，10⁻¹¹摩尔/升）减少了钠离子从管腔到间质的净移动，VIP还降低了跨上皮电位差；这两种激素的有效浓度处于正常血浆浓度范围内。胃泌素（5×10⁻⁷摩尔/升）和合成促胰液素（2×10⁻⁷摩尔/升）有类似作用，但仅在远高于正常血浆水平的浓度时才起作用。蛙皮素是胆囊收缩素八肽的类似物，即使在浓度为10⁻⁶摩尔/升时对导管功能也无影响。强效唾液分泌促进剂雨蛙肽（4×10⁻⁸摩尔/升）是一种假定的哺乳动物肠激素和神经递质物质P物质的类似物，可导致导管钠转运显著增加（在大鼠和兔中均如此）。得出的结论是，VIP和GIP通常在决定唾液电解质组成方面发挥作用，并且推测它们的作用可能被诸如P物质之类的速激肽所拮抗。
