Studies on the pancreatic D cells in the chicken.

生长抑素（Somatostatin， SS）是从绵羊下丘脑中分离出来的含有14个氨基酸的肽。SS不仅存在于神经组织中，也存在于内分泌细胞中。SS-28由SS-14的n端延伸组成，广泛分布于脊椎动物中。SS-14和SS-28可能来自同一前体，SS-14是由SS-28的裂解实验产生的。它可能是一个终端产品。SS-28与胰高血糖素细胞密切相关，SS-14与胰岛素细胞密切相关。SS-28比SS-14更有效地抑制胰岛素释放，但SS-14优先抑制胰高血糖素的释放。本研究主要目的是通过免疫组织化学方法来阐明A和B胰岛的d细胞是否产生不同形式的SS。材料与方法。用多聚甲醛固定几种鸟类和哺乳动物的胰腺和肾上腺，并用副质体固定。取厚度为4mum的连续切片，ABC法进行免疫组化染色。采用SS-14和SS-28[1-14]抗原预吸收法检测6种ss -抗血清对SS-14和SS-28[1-28]的特异性。结果和讨论。SS-14和SS-28抗血清染色鸡胰岛和肠的d细胞和肾上腺的A细胞[15-28]，但SS-28不染色[1-14]。乌鸦、鹅和鸵鸟的胰岛d细胞对SS-14也有免疫反应，但对SS-28没有免疫反应[1-14]。相反，猫、血清和麝鼠的胰岛d细胞对SS-14和SS-28进行免疫染色[1-14]。山羊和猫的肾上腺A细胞与SS-14和SS-28的抗血清发生反应[1-14]。总之，鸟类的胰岛D细胞和肾上腺A细胞都只含有SS-14。鸟类在进化过程中似乎具有生长抑素的特征。

Somatostatin (SS) is a peptide containing 14 amino acid and isolated from the ovine hypothalamus. SS was found not only in nervous tissue but also endocrine cells. SS-28 consisting of an N-terminal extension of SS-14 is widely distributed in vertebrates. SS-14 and SS-28 may occur from the same precursor, and SS-14 is experimentally produced from the cleavage of SS-28. It may be a terminal product. The close association of SS-28 with glucagon cells, and of SS-14 with insulin cells, in the fish islets is implied. SS-28 is more potent than SS-14 in the inhibition of insulin release, but SS-14 preferentially inhibits glucagon release. The main object is immunohistochemically to elucidate whether the different forms of SS are produced in D-cells of A and B islets. Materials and Methods. Pancreas and adrenals of several species of birds and mammals were fixed with paraformaldehyde and mounted with paraplast. Serial sections 4mum in thickness were cut and performed the immunohistochemical staining by ABC method. Of six kinds of SS-antisera used, specificity of the antisera for SS-14 and SS-28 [1-28] was tested by preabsorption with SS-14 and SS-28[1-14]antigens.Results and Discussion. D-cells of islets and intestine, and A cells of adrenals in chickens stained with antisera against SS-14 and SS-28 [15-28] , but not with SS-28 [1-14]. Islet D-cells of crows, geese and ostrich also are immunoreactive for SS-14, but not for SS-28 [1-14]. Contrarity, islet D-cells of cats, serows and musk shrews immunostained for SS-14 and SS-28[1-14]. Adrenal A cells of goats and cats reacted with the antisera against SS-14 and SS-28 [1-14].Taken together, both islet D cells and adrenal A cells contain only SS-14 in the avian species. It seems likely that avian species is characteristic of somatostatin in the evolution.