Verdugo P
Ciba Found Symp. 1984;109:212-25. doi: 10.1002/9780470720905.ch15.
Experiments have been done to test the idea that mucins undergo postexocytotic swelling. Previous work led to the hypothesis that the glycoprotein network of the mucus gel is probably held together by entanglements and low energy bonds, rather than by interchain covalent bonding. Since glycoproteins and other proteins in the mucus are polyions, it was further proposed that mucus must be capable of swelling, with its swelling properties depending on the pH and ionic strength of the medium hydrating the mucus. Experiments using oestrous cervical mucus from cows as a model confirmed this prediction. Observations on tissue cultures of respiratory secretory cells reported here show that freshly secreted mucins also undergo swelling during and after exocytosis. This evidence supports the hypothesis that the rheological properties of mucus may be physiologically regulated by hydration via control of the transepithelial movement of water, ions and soluble proteins, rather than by variations in the degree of covalent cross-linking between glycoprotein chains as proposed earlier.
已经进行了实验来验证粘蛋白在胞吐后会发生肿胀这一观点。先前的研究得出了这样的假设，即黏液凝胶的糖蛋白网络可能是通过缠结和低能键维系在一起，而非链间共价键。由于黏液中的糖蛋白和其他蛋白质是聚离子，因此进一步提出黏液必定能够发生肿胀，其肿胀特性取决于水化黏液的介质的pH值和离子强度。以母牛发情期宫颈黏液为模型的实验证实了这一预测。此处报道的对呼吸道分泌细胞组织培养的观察结果表明，新分泌的粘蛋白在胞吐过程中及胞吐后也会发生肿胀。这一证据支持了这样的假设，即黏液的流变学特性可能是通过控制水、离子和可溶性蛋白质的跨上皮运动来实现水合作用的生理调节，而不是如先前提出的那样通过糖蛋白链间共价交联程度的变化来调节。
