Crystallographic investigation of the dried exudate of the major vestibular (Bartholin's) glands in women.

OBJECTIVE: The aim of this study was to investigate the dried secretion of human major vestibular glands in order to establish its crystallographic pattern and to compare the data with those obtained for other human genital biopolymers. STUDY DESIGN: After air drying, samples were examined comparatively under transmitted and polarized light. At first sight, dehydrated vestibular fluid exhibits a fern-like crystallographic pattern very similar in appearance to those described in mid-cycle cervical mucus and bulbo-urethral fluid. RESULTS: Dendritic structures fill the central space of all preparations, prolonged by apparently amorphous peripheral fucus-like expansions. Spherulitic interdendritic crystalline microstructures (ICMs) can be considered a constant feature of dried vestibular exudate. In contrast with dendritic formations, fucus-like expansions and isolated spherulites are anisotropic under polarized light. Anisotropy appears to be the guise of a luminescent border lining the dendrites or bright nodules shining on a dark background. CONCLUSION: The study confirms the close physico-chemical proximity of vestibular secretion, mid-cycle cervical mucus and bulbo-urethral fluid. However, if isotropic dendritic formations and anisotropic structures are grossly similar, the number and size of the anisotropic ICMs are typical of human vestibular secretion. The different patterns of ICMs observed in these three human biological hydrogels demonstrate differences in the salt concentrations.

Involvement of the glycoproteic meshwork of cervical mucus in the mechanism of sperm orientation.

BACKGROUND: The aim of this study was to investigate the influence of the solid phase of the mucus hydrogel in facilitating the upward movement of spermatozoa during the menstrual cycle. METHODS: A total of 171 sperm migration experiments using 47 selected ovulatory mucus samples were performed in vitro in tubes of various shape and diameter. Physical constraints applied to cervical mucus combined with scanning electron microscopy (SEM) techniques permitted analysis of the mechanism of sperm orientation within cervical mucus submitted to capillary constraints simulating the various conditions of sperm orientation in vivo. RESULTS: The results support the theory according to which spermatozoa entering the cervical canal are constrained to follow the oriented micellar lines of strain. Stretched ovulatory mucus exhibits noticeable prevalent orientation of most filaments aligned in a manner roughly parallel to the traction axis. By contrast, even after strong stretching applied to luteal-type mucus and longer contact periods, the alignment of glycoproteic meshes was not sufficiently marked to allow spermatozoa to orient themselves and to move rapidly. The results are discussed as a function of the variations occurring in the three-dimensional macromolecular arrangement of the glycoproteic framework subjected to flow constraints. CONCLUSIONS: The study confirms that there is a close relationship between the three-dimensional arrangement of the mucus framework and the ability of spermatozoa to move rapidly in a given direction. The high resolution and three-dimensional aspect of SEM micrographs support the correlation of sperm orientation with current data on rheologic properties of biologic hydrogels.