Effect of non-Newtonian fluid properties on bovine sperm motility

Toru Hyakutake, Hiroki Suzuki, Satoru Yamamoto

    • 2 Citations

    Abstract

    The swimming process by which mammal spermatozoa progress towards an egg within the reproductive organs is important in achieving successful internal fertilization. The viscosity of oviductal mucus is more than two orders of magnitude greater than that of water, and oviductal mucus also has non-Newtonian properties. In this study, we experimentally observed sperm motion in fluids with various fluid rheological properties and investigated the influence of varying the viscosity and whether the fluid was Newtonian or non-Newtonian on the sperm motility. We selected polyvinylpyrrolidone and methylcellulose as solutes to create solutions with different rheological properties. We used the semen of Japanese cattle and investigated the following parameters: the sperm velocity, the straight-line velocity and the amplitude from the trajectory, and the beat frequency from the fragellar movement. In a Newtonian fluid environment, as the viscosity increased, the motility of the sperm decreased. However, in a non-Newtonian fluid, the straight-line velocity and beat frequency were significantly higher than in a Newtonian fluid with comparable viscosity. As a result, the linearity of the sperm movement increased. Additionally, increasing the viscosity brought about large changes in the sperm flagellar shape. At low viscosities, the entire flagellum moved in a curved flapping motion, whereas in the high-viscosity, only the tip of the flagellum flapped. These results suggest that the bovine sperm has evolved to swim toward the egg as quickly as possible in the actual oviduct fluid, which is a high-viscosity non-Newtonian fluid.

    Original languageEnglish
    Pages (from-to)2941-2947
    Number of pages7
    JournalJournal of Biomechanics
    Volume48
    Issue number12
    DOIs
    StatePublished - 2015 Sep 18

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    Fluids
    Viscosity
    Mammals
    Trajectories
    Water

    Keywords

    • Bovine sperm
    • Flagellum
    • Image analysis
    • Non-Newtonian fluid
    • Viscosity

    ASJC Scopus subject areas

    • Orthopedics and Sports Medicine
    • Rehabilitation
    • Biophysics
    • Biomedical Engineering

    Cite this

    Effect of non-Newtonian fluid properties on bovine sperm motility. / Hyakutake, Toru; Suzuki, Hiroki; Yamamoto, Satoru.

    In: Journal of Biomechanics, Vol. 48, No. 12, 18.09.2015, p. 2941-2947.

    Research output: Contribution to journalArticle

    Hyakutake, Toru; Suzuki, Hiroki; Yamamoto, Satoru / Effect of non-Newtonian fluid properties on bovine sperm motility.

    In: Journal of Biomechanics, Vol. 48, No. 12, 18.09.2015, p. 2941-2947.

    Research output: Contribution to journalArticle

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    title = "Effect of non-Newtonian fluid properties on bovine sperm motility",
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