School of Veterinary Medicine and Animal Science, Kitasato University, Towada-shi, Aomori 034-8628, Japan.
J Anim Sci. 2010 Jun;88(6):2103-7. doi: 10.2527/jas.2009-1920. Epub 2010 Feb 26.
The roles of pancreatic polypeptide (PP) have not been determined in ruminant animals. The aim of the present study was to examine the role of PP in the regulation of ghrelin secretion in sheep. Two experiments were conducted using four 2-yr-old Suffolk wethers fed a maintenance diet of alfalfa hay cubes. In Exp. 1, the effects of feeding on blood ghrelin and PP concentrations were examined in scheduled-fed sheep. Blood samples were collected every 10 min from 30 min before to 360 min after feeding. Plasma PP concentrations were transiently increased from the preprandial average value to the values from 30 to 60 min after feeding and gradually decreased (P < 0.05) to stable values from 150 to 180 min. The values from 30 to 60 min were greater (P < 0.05) than those from 150 to 360 min. In contrast, plasma ghrelin concentrations were gradually decreased (P < 0.01) by feeding. The values from 60 to 360 min were less (P < 0.01) than the preprandial average value. In Exp. 2, the effects of continuous PP infusion on ghrelin secretion were examined in feed-deprived sheep. The animals were deprived of feed for 48 h before PP infusion. The PP-treated group intravenously received synthetic bovine PP at a rate of 10 pmol.kg(-1 )of BW.min(-1) for 180 min. Blood samples were collected every 10 min from 30 min before to 180 min after the commencement of PP infusion. Plasma PP concentrations reached a plateau within 30 min after the commencement of PP infusion. Plasma ghrelin concentrations were decreased (P = 0.002, 0.016, 0.007) by PP infusion at 160, 170, and 180 min, respectively. In conclusion, plasma ghrelin and PP concentrations were decreased and increased, respectively, in response to feeding in ruminant animals. Furthermore, PP could depress ghrelin secretion.
在反刍动物中，胰多肽（PP）的作用尚未确定。本研究的目的是研究 PP 在调节绵羊胃饥饿素分泌中的作用。使用 4 只 2 岁的萨福克羊进行了两项实验，这些羊以苜蓿干草块为维持日粮。在实验 1 中，检查了定时喂养对绵羊血液胃饥饿素和 PP 浓度的影响。在喂食前 30 分钟至喂食后 360 分钟，每 10 分钟采集一次血液样本。血浆 PP 浓度从预喂食的平均值短暂升高到喂食后 30 至 60 分钟的值，并逐渐下降（P < 0.05）至 150 至 180 分钟的稳定值。30 至 60 分钟的值大于（P < 0.05）150 至 360 分钟的值。相比之下，血浆胃饥饿素浓度逐渐降低（P < 0.01），喂食后。60 至 360 分钟的值小于（P < 0.01）预喂食的平均值。在实验 2 中，检查了连续输注 PP 对胃饥饿素分泌的影响，这些羊在 PP 输注前被禁食 48 小时。PP 处理组以 10 pmol.kg(-1) 的 BW.min(-1) 静脉内输注合成牛 PP 180 分钟。在 PP 输注开始前 30 分钟至 180 分钟，每 10 分钟采集一次血液样本。PP 输注开始后 30 分钟内，血浆 PP 浓度达到平台期。PP 输注分别在 160、170 和 180 分钟时使血浆胃饥饿素浓度降低（P = 0.002、0.016、0.007）。总之，在反刍动物中，进食会导致血浆胃饥饿素和 PP 浓度分别降低和升高。此外，PP 可以抑制胃饥饿素的分泌。
