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.