Human cervical mucus. III. Isolation and characterization of rheologically active mucin

Abstract

Several common mucolytic agents were screened for their ability to solubilize cervical mucus without incurring irreversible losses in mucus viscoelasticity. Sodium thiocyanate was selected on the basis of its effectiveness and handling convenience, and solubilized mucus was fractionated by gel filtration on Sepharose columns. The excluded mucin fraction was characterized by a high neutral hexose to protein ratio and contained all of the elasticity of thiocyanate-treated whole mucus. The concentration of mucin in individual mucus samples collected throughout the ovulatory menstrual cycle was determined from column elution profiles. An increased relative amount of mucin was associated with samples collected during the ovulatory phase of the cycle, and a strong correlation was obtained when the percentage of mucin in individual samples was plotted against their respective storage moduli. These results indicate that the cyclic fluctuations in mucus viscoelasticity seen previously at constant concentrations of nondialyzable solids can be attributed to variations in mucin concentration. Evidence was also obtained, however, for compositional differences in mucus derived from different patients.

PIP: The isolation and characterization of rheologically active mucin was carried out in human cervical mucus. 6 common mucolytic agents (6 M urea, 65.7%; 2 M guanidine, 53.5%; .15 M sodium thiocyanate, 60.4%; .15M formamide, 54.7%; .1% Zephiran, 6.9%; and .075 M dithiothreitol, 70.3%) were screened for their ability to solubilize cervical mucus without incurring irreversible losses in mucus viscoelasticity. Sodium thiocyanate was selected for its effectiveness and handling convenience, and solubilins. The mucin fraction was characterized by a high neutral hexose to protein ratio and contained all of the elasticity of thiocyanate was selected for its effectiveness and handling convenience, and solubilized mucus was fractionated by gel filtration on Sepharose columns. The mucin fraction was characterized by a high neutral hexose to protein ratio and contained all of the elasticity of thiocyanate-treated whole mucus. Column elution profiles were used to determine the concentration of mucin in individual mucus samples collected throughout the ovulatory menstrual cycle. An increased relative amount of mucin was associated with the ovulatory phase of the cycle, and a strong correlation was obtained when the percentage of mucin in individual samples was plotted against the respective storage moduli. These data indicate that the cyclic fluctuations in mucus viscoelasticity seen previously at constant concentrations of nondialyzable solids can be attributed to variations in mucin concentration. Evidence was obtained for compositional differences in mucus derived from different patients.