7-hydroxy-2-(di-N-propylamino)tetralin-induced ejaculation in anaesthetised rat
Objective
To induce a complete ejaculatory response in anaesthetised rat. In this model, physiological markers of the emission and expulsion phases of ejaculation induced by the dopamine D3 preferring agonist 7-hydroxy-2-(di-N-propylamino)tetralin (7-OH-DPAT) can be measured. Contractions of the seminal vesicle and the bulbospongiosus muscle are regarded as physiological markers of, respectively, emission and expulsion phases of ejaculation (figure 1).
Summarized methodology:
Under anaesthesia (isoflurane, urethane or pentobarbital), the carotid artery and the right seminal vesicle are catheterized to measure concomitantly arterial pressure (AP) and seminal vesicle pressure (SVP). Electrical activity of the bulbospongiosus muscle (BS EMG) is also recorded. Physiological markers are monitored before and over 30 min after PCA systemic injection (i.v. or i.p.). Computerized analysis of the recordings is then performed a posteriori using custom-written analysis programs (Sadoc, CNRS, Gif-sur-Yvette, France).
Endpoints
• Number and latency of ejaculations (corresponding to the expulsion of a seminal plug)
• Number, latency, amplitude, duration and area under the curve of SVP increases
• Number, latency, frequency and duration of BS contractions
• Time interval between SVP increase and BS contractions
Remarks
7-OH-DPAT triggers ejaculation by stimulating dopamine D2/D3 receptors at the brain level. Therefore, this model is suitable for studying peripheral and spinal modulations of the ejaculatory process but also supra-spinal modulations that involve dopaminergic system.
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| Figure 1:Example of recording of seminal vesicle pressure and bulbospongiosus muscle electromyogram (EMG) during ejaculation induced by i.v. 7-OH-DPAT in isoflurane anaesthetised rat (Pelvipharm, internal data). |
J Sex Med (2009) : 6:980-988
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Neuroscience (2007) : 149:636-641
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Neuroscience (2007) : 145:605-610
Links to applicable Targeted disorders / Pathophysiological models
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