Uvnäs B, Aborg C H
Department of Pharmacology, Karolinska Institute, Stockholm, Sweden.
Acta Physiol Scand. 1988 Mar;132(3):297-311. doi: 10.1111/j.1748-1716.1988.tb08333.x.
On superfusion of chromaffin granules from bovine adrenals with isotonic sodium and potassium salts, catecholamines and ATP were released in parallel and both in accordance with ion exchange kinetics. An artificial model was prepared by mixing a cationic (IRC-50) and an anionic (IR-4B) ion exchanger with COO- and NH+3 groups, respectively, as binding sites. This mixed ion exchanger showed in its storage and release of CA+ and ATP- striking similarities to the chromaffin granules. Within the pH range given for the interior of the granules--5.5-6--the artificial model even stored and released CA+ and ATP- within the same molar ratio as observed for the granules. We hypothesize that the chromaffin granule matrix in its storage and release functions operates as an amphoteric ion exchanger with COO- and NH+3 groups as the binding sites.
用等渗的钠盐和钾盐对牛肾上腺嗜铬颗粒进行灌注时，儿茶酚胺和三磷酸腺苷（ATP）会同时释放，且均符合离子交换动力学。通过分别将带有-COO⁻和-NH₃⁺基团作为结合位点的阳离子（IRC - 50）和阴离子（IR - 4B）离子交换剂混合，制备了一个人工模型。这种混合离子交换剂在储存和释放钙离子（Ca⁺）和三磷酸腺苷阴离子（ATP⁻）方面与嗜铬颗粒表现出惊人的相似性。在给定的颗粒内部pH范围（5.5 - 6）内，该人工模型储存和释放Ca⁺和ATP⁻的摩尔比甚至与颗粒中观察到的相同。我们推测，嗜铬颗粒基质在其储存和释放功能中作为一种两性离子交换剂发挥作用，以-COO⁻和-NH₃⁺基团作为结合位点。
