Morisset J, Wong H, Walsh J H, Lainé J, Bourassa J
Service de Gastro-entérologie, Département de Médecine, Université de Sherbrooke, Québec, Canada.
Am J Physiol Gastrointest Liver Physiol. 2000 Jul;279(1):G148-56. doi: 10.1152/ajpgi.2000.279.1.G148.
In rodents, cholecystokinin (CCK) induces pancreatic enzyme secretion and pancreas growth through its CCK(A) receptors. It is unknown whether occupation of the CCK(B) receptors present in pig and human pancreas can cause the same effects. This study evaluates CCK(B) receptor expression in rat, mouse, pig, and fetal human pancreata using Northern blot, Western blot, and immunofluorescence techniques. The reported 2.7-kb CCK(B) receptor mRNA transcript in the rat brain and gastric fundus is absent in pancreas; the message was, however, detected by RT-PCR and by a CCK(B) receptor antibody as an 80-kDa protein present uniquely in islet delta-cells. Proteins of 50 and 80 kDa appear in mouse pancreas, and proteins of 50 and 115 kDa appear in pig and human pancreas, respectively, all localized in islet delta-cells. Gastrin mRNAs are strongly present in fetal rat pancreas, and the hormone is localized in islets; both are repressed 10 days after birth. In conclusion, the CCK(B) receptors are present in pancreas of four species with exclusive location in islet delta-cells. In such a location, they could be indirectly involved in the control of enzyme secretion.
在啮齿动物中，胆囊收缩素（CCK）通过其CCK（A）受体诱导胰腺酶分泌和胰腺生长。猪和人胰腺中存在的CCK（B）受体被激活是否会产生相同的效应尚不清楚。本研究采用Northern印迹法、Western印迹法和免疫荧光技术评估大鼠、小鼠、猪和人胎儿胰腺中CCK（B）受体的表达情况。大鼠脑和胃底中报道的2.7 kb CCK（B）受体mRNA转录本在胰腺中不存在；然而，通过RT-PCR和CCK（B）受体抗体检测到该信息，其为一种仅存在于胰岛δ细胞中的80 kDa蛋白。50 kDa和80 kDa的蛋白出现在小鼠胰腺中，50 kDa和115 kDa的蛋白分别出现在猪和人胰腺中，均定位于胰岛δ细胞。胃泌素mRNA在胎鼠胰腺中大量存在，且该激素定位于胰岛；出生后10天两者均受到抑制。总之，CCK（B）受体存在于四种动物的胰腺中，且仅位于胰岛δ细胞。在这样的位置，它们可能间接参与酶分泌的调控。
