研究のタイプ: 医学/生物学の研究 (experimental study)

[ラットの片側精巣捻転/捻転矯正後の同側および対側の精管における電界刺激誘発の二相性単収縮反応へのメラトニンの影響] tech./dosim.

The effects of melatonin on electrical field stimulation-evoked biphasic twitch responses in the ipsilateral and contralateral rat vasa deferentia after unilateral testicular torsion/detorsion.

掲載誌: Naunyn Schmiedebergs Arch Pharmacol 2005; 371 (5): 351-358

この研究は、片側精巣の捻転/ゆがみの後における輸精管運動障害の有無を検出する方法を検討した。実験的に片側精巣の捻転/ゆがみを生じさせたラットの同側および対側の輸精管に電気刺激(EFS)を与え、誘発される二相性けいれん収縮に変化を調べた。また、強力な抗酸化物質であるメラトニン(MLT)がこれらの収縮反応に与える効果も評価した。EFS誘発収縮の検査は、捻転/ゆがみ処置の2時間後または24時間後に実施した。また、EFS誘発二相性けいれん収縮反応を記録するために、同側および対側の輸精管を露出させた。同じ実験プロトコルをMLT処理ラットについても実施した。その結果、EFS誘発二相性収縮のどちらの相も、同側の輸精管では低下した;MLT処置群では、2時間後および24時間後の両相の低下がさらに大きくなった;対側の輸精管では、EFS誘発収縮の第1相は変化しなかったが、第2相は2時間後および24時間後に低下した;MLT処置群では、2時間後および24時間後の収縮の第2相を低下させたが、2時間後においてのみ第1相を低下させた;これらの知見は、MLTがラットの片側精巣捻転/歪み後の同側および反対側の輸精管におけるEFS誘発二相性けいれん収縮反応の抑制をもたらすことを示唆している、と報告している。

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研究目的(著者による)

To determine whether the electrical field stimulation-evoked biphasic contractions are altered in ipsilateral and contralateral rat vasa deferentia obtained from animals exposed to the unilateral testicular torsion/detorsion procedure. An impairment in vas deferens motility after unilateral testicular torsion/detorsion is known.

詳細情報

Unilateral testicular torsion is a clinical syndrome caused by torsion of the spermatic cord and is treated by a surgical detorsion procedure. There are no data in the literature examining the motility of the vas deferens after the torsion/detorsion procedure.
Animals were subjected to torsion of the left testis (rotated by twisting clockwise 720°) for 2 h and then detorsion was performed. Contractility studies were carried out 2 h or 24 h after detorsion. Vas deferens strips were prepared from both the ipsilateral and the contralateral site 2 h or 24 h after the detorsion procedure. The effects of melatonin (a strong antioxidant) on the contractile responses were also evaluated. For the melatonin-treated animals the same protocol was repeated.

影響評価項目

ばく露

ばく露 パラメータ
ばく露1: 1–64 Hz
Modulation type: pulsed
ばく露時間: intermittent, every 5 min
-

General information

Rats were divided into three groups of 6 animals each: Group 1 was used for control in which the animals were not subjected to any medical or surgical procedure, group 2 was stimulated with electric field whereas group 3 served as sham group.

ばく露1

主たる特性
周波数 1–64 Hz
タイプ
  • electric field
波形
  • pulsed
ばく露時間 intermittent, every 5 min
Additional information The following frequencies were used: 1 Hz, 2 Hz, 4 Hz, 8 Hz, 16 Hz, 32 Hz and 64 Hz.
Modulation
Modulation type pulsed
Pulse width 1 ms
Additional information

10 s trains of pulses

ばく露装置
ばく露の発生源/構造
  • platinum electrodes
パラメータ

No parameters are specified for this exposure.

方法 影響評価項目/測定パラメータ/方法

研究対象とした生物試料:
調査の時期:
  • ばく露中

研究の主なアウトカム(著者による)

The contractions of the vas deferens are biphasic: the first phase is attributed to ATP acting at P2X receptors and the second phase to noradrenaline at alpha1-receptors.
In the ipsilateral vas deferens both phases of electrical field stimulation-evoked contractions were decreased after torsion/detorsion. Melatonin treatment increased torsion/detorsion-induced reduction of both phases of contractions after 2 h and 24 h.
In the contralateral vas deferens, the first phase of electrical field stimulation-evoked contractions was not altered, while the second phase of contractions was diminished 2 h and 24 h after detorsion. Although melatonin decreased the second phase of contractions 2 h and 24 h after detorsion, it reduced the first phase of contractions only 2 h after detorsion.
These data suggest that melatonin produces an inhibition on electrical field stimulation-evoked biphasic twitch responses in the ipsilateral and contralateral rat vasa deferentia following unilateral testicular torsion/detorsion in the rat.

研究の種別:

研究助成