Can hypoxia enhance sexual arousal?-Molecular-biological analysis of the hypothalamus in male rats placed with oestrous female rats under hypoxic conditions-

To clarify whether sexual arousal could be enhanced by hypoxia, and to explain the pathogenesis of autoerotic death (AED)/autoerotic asphyxiation (AEA), we investigated the molecular-biological and hormonal interactions in male rats between hypoxia (10% O2) and sexual stimulation (placing male rats with oestrous female rats) using hypothalamus tissue and serum. Serum oxytocin concentration was significantly increased by either hypoxia or sexual stimulation without significant change of Oxt mRNA expression. Serum concentration of adrenocorticotropic hormone was significantly elevated by sexual stimulation, although serum concentration of copeptin was significantly suppressed by hypoxia. Moreover, serum concentration of luteinising hormone was increased by hypoxia. These results suggested that hypoxia would complicatethe response to sexual stimulation, and effect a change in sexual arousal. Moreover, sexual stimulation significantly suppressed mRNA expressions of Hspa4 and Hyou1, which might indicate that sexual stimulation reducestolerance to hypoxia/ischaemia. Accordingly, it is possible that AED/AEA would be attributed to a reduced tolerance to hypoxia/ischaemia induced byattempts to obtain sexual arousal under a hypoxic condition and would not be a simple accident.