Newgard C B, Holst J J
Acta Endocrinol (Copenh). 1981 Dec;98(4):564-72. doi: 10.1530/acta.0.0980564.
Four different extraction procedure representative of methods commonly employed in the isolation of somatostatin like immunoreactivity (SLI) were tested for their ability to extract large MW forms of SLI from porcine, canine and human pancreas. The yield of SLI and recovery of added somatostatin was much higher with methods involving traditional acid/ethanol extraction (methods I and II) than with methods involving boiling of tissues in water or 2 M CH3COOH (methods III and IV). Porcine and canine pancreas extracted by methods III and IV (but not methods I and II) revealed remarkable molecular heterogeneity upon gel filtration, but immuno-affinity-chromatography eliminated the largest forms. A component of approximately 3000 daltons was immunoabsorbable and resisted refiltration in 8 M urea. No large forms were detectable in human pancreas. The SLI peaks eluting at the position of synthetic somatostatin could be resolved into two components, one of which was lacking C-terminal immunoreactivity. It is concluded that the method of extraction as well as the species investigated and the specificity of the antisera employed will influence significantly the results of studies of the tissue forms of somatostatin.
对四种不同的提取程序进行了测试，这些程序代表了在分离类生长抑素免疫反应性（SLI）中常用的方法，以检验它们从猪、犬和人胰腺中提取大分子形式SLI的能力。与涉及在水中或2M CH3COOH中煮沸组织的方法（方法III和IV）相比，采用传统酸/乙醇提取的方法（方法I和II）的SLI产量和添加的生长抑素回收率要高得多。用方法III和IV（而不是方法I和II）提取的猪和犬胰腺在凝胶过滤时显示出显著的分子异质性，但免疫亲和色谱法消除了最大的形式。一种约3000道尔顿的成分具有免疫吸附性，并且在8M尿素中抗再过滤。在人胰腺中未检测到大分子形式。在合成生长抑素位置洗脱的SLI峰可分解为两个成分，其中一个缺乏C末端免疫反应性。得出的结论是，提取方法以及所研究的物种和所用抗血清的特异性将显著影响生长抑素组织形式的研究结果。
