Svennersten K, Nelson L, Arvinder K, Uvnäs-Moberg K
Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala.
J Dairy Sci. 1989 Sep;72(9):2276-82. doi: 10.3168/jds.S0022-0302(89)79358-9.
In monogastric animals, suckling influences the secretion of gastrointestinal hormones during lactation. The aim of the present study was to investigate whether similar effects are induced by milking in cows. Experiments were performed on four cows in midlactation. Blood samples were drawn from a chronic jugular vein catheter and gastrin, and somatostatin were determined by radioimmunoassay. Milking and feeding increased plasma gastrin. Somatostatin increased at morning milking and at feeding, but it decreased at evening milking. Atropine injected subcutaneously 30 min before milking increased resting concentrations of gastrin but decreased resting concentrations of somatostatin. Feeding-induced release of gastrin remained but the milking-induced release disappeared. The milking- and feeding-induced effect on somatostatin became more marked. We suggest that milking influences gastrin and somatostatin via activation of the vagal nerves. The gastrin release caused by milking may be mediated via a cholinergic mechanism, whereas the atropine resistant effect on gastrin caused by feeding and on somatostatin caused by both milking and feeding suggest that a noncholinergic, perhaps peptidergic, transmitter may be involved.
在单胃动物中，哺乳会影响泌乳期胃肠激素的分泌。本研究的目的是调查挤奶是否会在奶牛中引发类似的效应。对4头处于泌乳中期的奶牛进行了实验。从一条慢性颈静脉导管采集血样，并用放射免疫分析法测定胃泌素和生长抑素。挤奶和喂食会增加血浆胃泌素水平。生长抑素在早晨挤奶和喂食时升高，但在晚上挤奶时降低。在挤奶前30分钟皮下注射阿托品，会增加胃泌素的静息浓度，但降低生长抑素的静息浓度。喂食诱导的胃泌素释放仍然存在，但挤奶诱导的释放消失了。挤奶和喂食对生长抑素的诱导作用变得更加明显。我们认为，挤奶通过迷走神经的激活影响胃泌素和生长抑素。挤奶引起的胃泌素释放可能通过胆碱能机制介导，而喂食对胃泌素以及挤奶和喂食对生长抑素的阿托品抗性效应表明，可能涉及一种非胆碱能、或许是肽能的递质。
