(006) Methamphetamine-Induced Vaginal Lubrication

Abstract

Abstract Introduction Vaginal dryness is a frequent complaint, especially in post-menopausal women. The physiology underlying the production of vaginal lubrication in response to arousing stimuli is established; however, no current pharmacological agents successfully target mechanisms within this physiology. Previous research from our lab has demonstrated that female methamphetamine (meth) users experience the immediate production of excessive vaginal lubrication, accompanied by a warmth or flushing sensation spreading from the chest areas to the pelvic region, when using the drug intravenously (IV). The physiological source of this previously undescribed effect of meth could present a potential mechanism to enhance a woman’s natural production of vaginal lubrication, providing a potentially life-changing option to patients experiencing vaginal dryness. Objectives The purpose of the current study was to determine if vaginal lubrication induced by IV meth use reported in a previous study from our lab occurs in rats, and if this effect is dose-dependent. This study also sought to begin to uncover the mechanism behind this phenomenon. Methods Adult female Wistar rats (n=8) were implanted with chronic indwelling jugular catheters and allowed at least one week to recover from surgery. Rats anesthetized with isoflurane gas were intravenously infused with one of seven doses of meth ranging from 0.015-0.96 mg/kg meth or saline IV via the implanted catheter. Pre-weighed cotton-tipped swabs inserted into the vaginal canal collected fluid secreted following drug administration. The change in weight of the swab was taken as the weight of fluid produced. Consequent studies examined several signaling molecules in plasma known to have an influence on vaginal lubrication, including the steroid hormones estradiol, progesterone and testosterone, as well as the gaseous vasodilator nitric oxide. These molecules were measured at time points up to 60 minutes after meth administration. Results As hypothesized, meth increased vaginal lubrication in a dose-dependent manner. Doses of 0.06 and 0.24 mg/kg of meth induced significant increases in vaginal lubrication compared to saline. Further, compared to pre-meth levels, significant increases in estradiol were seen at two and 15 minutes after meth administration. Significant increases in progesterone, testosterone and nitric oxide were seen ten minutes after meth administration. Conclusions This study has far-reaching implications since the majority of women will experience vaginal dryness at least once, if not recurrently. The underlying mechanism of meth-induced vaginal lubrication, when elucidated, may provide a pharmacological target in treating not only meth use disorder, but also the millions of women suffering from vaginal dryness. Disclosure No.