Beschreibung:
<jats:p><jats:bold>The ciliary beat frequency (CBF) of guinea‐pig fimbria during the ovarian cycle was measured by video microscopy using a high‐speed camera (500 Hz). In the follicular phase, with increasing concentrations of β‐oestradiol ([βE<jats:sub>2</jats:sub>]) and a low concentration of progesterone ([PRG]), CBF increased from 13.5 to 16 Hz. In the ovulatory phase, with further increase of [βE<jats:sub>2</jats:sub>], CBF decreased gradually from 16 to 13.5 Hz. In the early luteal phase, with low [PRG] and [βE<jats:sub>2</jats:sub>], CBF increased to ∼17 Hz; however, in the middle luteal phase, with increasing [PRG], CBF decreased (∼12 Hz), and in the late luteal phase, with decreasing [PRG], CBF increased to ∼15 Hz. Then, in the resting phase, with low [βE<jats:sub>2</jats:sub>] and [PRG], CBF decreased immediately to ∼14 Hz. The CBF of the fimbria was measured in guinea‐pigs treated with β‐oestradiol benzoate (βE<jats:sub>2</jats:sub>B) or medroxyprogesterone (mPRG). A low dose of βE<jats:sub>2</jats:sub>B increased CBF to ∼14.5 Hz, whereas a high dose decreased it to ∼11 Hz. A βE<jats:sub>2</jats:sub> receptor blocker, ICI‐182,780, abolished the βE<jats:sub>2</jats:sub>B‐induced CBF changes and maintained CBF at ∼12.0 Hz. Medroxyprogesterone decreased CBF to ∼12.5 Hz, and mifepristone (a PRG receptor blocker) abolished the mPRG‐induced CBF decrease and maintained CBF at ∼15 Hz. The addition of both blockers increased CBF to ∼18 Hz, suggesting that activation of βE<jats:sub>2</jats:sub> or PRG receptors decreases the CBF of the fimbria. In conclusion, a moderate [βE<jats:sub>2</jats:sub>] increase maintains a high CBF (15.5 Hz) in the follicular phase, and then further [βE<jats:sub>2</jats:sub>] increase decreases CBF to 13.5 Hz in the ovulatory phase. In the early and late luteal phase, low [βE<jats:sub>2</jats:sub>] and [PRG] increase CBF to 17 and 15 Hz, respectively, and in the middle luteal phase a high [PRG] decreases CBF (to ∼12 Hz). Thus, the CBF of the fimbria was controlled by signals via βE<jats:sub>2</jats:sub> and PRG receptors in guinea‐pigs.</jats:bold></jats:p>