Scanes Colin G, Jaszcza Klaudia, Gajewska Alina, Pierzchala-Koziec Krystyna
Department of Biological Sciences, University of Wisconsin Milwaukee, 3209 N Maryland Ave, Milwaukee, WI 53211, USA.
Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Mickiewicza 21, 31-120 Krakow, Poland.
Animals (Basel). 2025 Jun 9;15(12):1702. doi: 10.3390/ani15121702.
The gastrointestinal (GI) tract is under neural, endocrine and paracrine control. The release (basal and in the presence of either cholinergic and opioid antagonists) of Met-enkephalin, insulin-like growth factor 1 (IGF-1) and somatostatin (SRIF) was determined quantitatively in vitro using explants of the crop, proventriculus and duodenum from either day 0 or day 1 chicks. In addition, the effects of cholinergic and opioid antagonists on PENK gene expression were examined. Thus, the aim of this study was to determine the roles of cholinergic and opioid receptors in the GI tract in newly hatched chickens. Moreover, the effect of IGF-1 and Met-enkephalin on cell division in duodenal explants in vitro was determined. There was both the release of Met-enkephalin from, and PENK expression in, the explants of the crop, proventriculus and duodenum tissue. This is the first report of any neuropeptide(s) being synthesized in and/or released from the crop. In vitro release of Met-enkephalin, IGF-1 and SRIF from duodenal and proventriculus explants was influenced ( < 0.01) by either cholinergic or opioid antagonists; for instance, in the presence of atropine, decreases ( < 0.001) of 17.8% and 57.7% are seen, respectively, in Met-enkephalin release and PENK expression in crop explants from day 1 chicks. Moreover, in the presence of atropine, there were increases ( < 0.001) of 47.7% and 70.9% in IGF-1 release in proventriculus explants from, respectively, day 0 and day 1 chicks. Met-enkephalin and/or IGF-1 stimulated the cell division of duodenal explants in vitro. This is the first report of Met-enkephalin release and PENK expression in the avian crop and of the effects of cholinergic or opioid antagonists on these factors. It is also the first report of either cholinergic or opioid control of IGF-1 release in the periphery of any species. There were strong relationships ( < 0.05) between the release of Met-enkephalin and that of IGF-1 in the duodenum and between the release of SRIF and that of IGF-1 in the proventriculus. This is the first report of IGF-1 and Met-enkephalin stimulating ( < 0.001) the proliferation of duodenal cells and, together, exerting a synergist effect. It is concluded that the release of Met-enkephalin, IGF-1 and SRIF from foregut regions is under tonic cholinergic and opioid control.
胃肠道受神经、内分泌和旁分泌的控制。利用0日龄或1日龄雏鸡的嗉囊、腺胃和十二指肠外植体，在体外定量测定了甲硫氨酸脑啡肽、胰岛素样生长因子1（IGF-1）和生长抑素（SRIF）的释放（基础释放以及在胆碱能和阿片类拮抗剂存在的情况下的释放）。此外，还研究了胆碱能和阿片类拮抗剂对PENK基因表达的影响。因此，本研究的目的是确定胆碱能和阿片受体在刚孵出雏鸡胃肠道中的作用。此外，还测定了IGF-1和甲硫氨酸脑啡肽对体外十二指肠外植体细胞分裂的影响。嗉囊、腺胃和十二指肠组织外植体中均有甲硫氨酸脑啡肽的释放和PENK表达。这是关于任何神经肽在嗉囊中合成和/或释放的首次报道。十二指肠和腺胃外植体中甲硫氨酸脑啡肽、IGF-1和SRIF的体外释放受胆碱能或阿片类拮抗剂的影响（P<0.01）；例如，在阿托品存在的情况下，1日龄雏鸡嗉囊外植体中甲硫氨酸脑啡肽的释放和PENK表达分别降低（P<0.001）17.8%和57.7%。此外，在阿托品存在的情况下，0日龄和1日龄雏鸡腺胃外植体中IGF-1的释放分别增加（P<0.001）47.7%和70.9%。甲硫氨酸脑啡肽和/或IGF-1在体外刺激十二指肠外植体的细胞分裂。这是关于甲硫氨酸脑啡肽在禽类嗉囊中的释放和PENK表达以及胆碱能或阿片类拮抗剂对这些因子影响的首次报道。这也是关于任何物种外周组织中IGF-1释放受胆碱能或阿片类控制的首次报道。十二指肠中甲硫氨酸脑啡肽的释放与IGF-1的释放之间以及腺胃中SRIF的释放与IGF-1的释放之间存在密切关系（P<0.05）。这是关于IGF-1和甲硫氨酸脑啡肽刺激（P<0.001）十二指肠细胞增殖并共同发挥协同作用的首次报道。研究得出结论，前肠区域中甲硫氨酸脑啡肽、IGF-1和SRIF的释放受紧张性胆碱能和阿片类控制。
