Introduction. A specially formulated alprostadil cream, femprox, as an investigational medication has been studied for the treatment of female sexual arousal disorder in several clinical trials. However, few researchers have investigated the mechanism of the alprostadil cream on the central nervous system (CNS).
Aim. The purpose of this study is to investigate the possible central mechanisms of the alprostadil cream used in the vagina of rats.
Methods. The effects of intravaginal application of the alprostadil cream on neuronal activities in the paraventricular nucleus of hypothalamus (PVN) and basomedial amygdala nucleus (BMA) were studied by extracelluar unit-firing recording, and the expression of oxytocin-immunoreactive (OT-IR) neurons and c-fos-immunoreactive (c-fos-IR) neurons in the PVN and superoptic nuclei (SON) was tested by immunocytochemical assay in anesthetized rats.
Main Outcome Measures. The firing frequency of neurons in the PVN and BMA; the expression of OT-IR neurons and c-fos-IR neurons in the PVN and SON.
Results. Our data showed that 70% of the neurons in the PVN and 36% of the neurons in the BMA were excited by application of the alprostadil cream. Compared with the placebo cream, the alprostadil cream administered could significantly increase the expression of OT-IR and c-fos-IR neurons in the PVN of hypothalamus, but not in the SON.
Conclusion. Our results suggest that the application of the alprostadil cream could act on the genital nerve terminals to facilitate the neurons of the PVN and BMA in the CNS, and increase the expression of oxytocin in the PVN to induce sex behaviors. Sun X, Xu L, Zhang J, Guo F, and Tang M. The effects of alprostadil on hypothalamic and amygdalar function and the central expression of oxytocin: A potential central role of alprostadil cream. J Sex Med 2009;6:81–90.