Oestrogen-mediated hormonal imbalance precipitates erectile dysfunction

Abstract

Declining testosterone (T) in an aging male offsets the equilibrium between androgen and oestrogen (oestradiol, E 2 ) with a resultant increase in E 2 -T ratio. Similar functional hormone imbalance is existent in clinical states of hypogonadism and is likely to arise from exposure of males to environmental oestrogens. The pathophysiological significance of this derangement on erectile function, hitherto unknown, was estimated in sexually mature male rats following acute and chronic treatment with oestrogen. A total of 60 male Sprague-Dawley rats (200-250 g) were divided into control and two treatment groups, administered 0.01 and 0.1 mg of oestradiol through oral gavage daily for 1 week (n ¼ 30, acute study) and 12 weeks (n ¼ 30, long-term study), respectively. Sexual activity in the presence of hormonally primed female rats and intracavernous pressure (ICP) response to electrical stimulation estimated treatment-induced changes, which were correlated with hormone levels and penile morphology at 12 weeks. Following two to five-fold elevation in serum E 2 levels (and simultaneous reduction in testosterone), there was a significant prolongation of mount, intromission, ejaculation latencies and some decrease in frequencies. The ICP response to nerve stimulation was also impaired in all the treated groups. Histologically, trichrome staining highlighted the cavernosal connective tissue hyperplasia in the long-term study groups. Results of this investigation indicate that oestradiol causes pathophysiological changes in erectile function. These observations provide an indirect evidence for the possible sexual health hazards in man upon inadvertent exposure to environmental oestrogens, ageing and derangement of E 2 -T ratio.

Levels of estradiol and testosterone are altered in Chinese men with sexual dysfunction

“…Then, it was proposed that excess of estradiol could be responsible for sexual function and dysfunction in men (Cohen, 1998). And animal experiment with rats indicated that estrogen-mediated hormonal imbalance precipitates ED (Adaikan & Srilatha, 2003). Our data reported that no significant difference in testosterone levels had been found among ED patients and normal control groups, which is controversial to some previous studies (Srilatha & Adaikan, 2011).…”

“…In addition, estrogens, in particular estradiol, regulate the initial part of the emission phase of ejaculation, a critical phase of ejaculation latency (Vignozzi et al, 2008). Rats with increased estradiol levels had significant prolongation of ejaculation latencies and impaired intracavernous pressure (Adaikan & Srilatha, 2003), and elevated estradiol and low testosterone levels are associated with the severity of ED (Srilatha & Adaikan, 2011). Here, we proposed that the homeostasis between estradiol and testosterone could be involved in orchestrating the regulation of male sexual function, and we aim to investigate the association between the hormonal profile and the incidence of PE, ED, or PE combined with ED.…”

Endocrine milieu and erectile dysfunction: is oestradiol–testosterone imbalance, a risk factor in the elderly?

“…In another study too, long-term therapeutic efficacy of tadalafil in improving International Index of Erectile Function scores and sexual function was correlated to increase in T/E 2 ratio (resulting more from E 2 decrease, rather than T increase). 52 There are also direct evidences from animal studies including dose-related inhibitory effect of intromission and postejaculatory mounting latencies by E 2 , 53 and reversal or normalisation of sexual function following E 2 withdrawal. 54 Taken together, it may be postulated that the opposing effects of androgen and oestrogen in sexual physiology may overlie a delicate 'yin yang' balance with the possibility of triggered cross-talk and functional derangement when the ratio is disturbed.…”

Relation of Sex Steroid Hormones to Genital Tissue Structure and Arousal: A Sampling of Manuscripts Discussing Endocrinologic Sexual Dysfunction

“…Several articles [1][2][3][4][5] concerning mechanistic studies in sex steroid hormones and sexual function/ dysfunction have been published recently in the IJIR: The Journal of Sexual Medicine, consistent with the contemporary nature of this physiological/ pathophysiological association. In 2001, Park et al 1 reported on three groups of female New Zealand White rabbits (control and bilateral oophorectomy with and without estrogen replacement).…”