The etiology of premature ejaculation starting from a bihormonal model of normal sexual stimulation

Abstract

Although the physiology of normal sexual intercourse is not yet suf®ciently elucidated, the studies referring to the cause of premature ejaculation (PE) seem to be fairly advanced. Thus, attempts are made to explain the etiology of PE by factors generating and maintaining this dysfunction, in close relationship with`the importance of physiological spinal ejaculatory mechanism to the understanding of PE'. 1 ± 3 By changing the order of approaching this subject (at ®rst the physiology and then a possible pathophysiology), conclusions may be drawn which require a revision of the current trends.The psychosensory sexual excitation is sympathoparasympathetically (Sp ± Pp) mediated. 2,4,5 The Sp sexual excitation assures the emission re¯ex, while the expulsion re¯ex is a somatic effector answer, 2 probably with a Pp origin.Classically, the physiological sexual excitation is induced in men by testosterone (Tt) and in women by estrogens (Es). The Tt ± Es antagonism is often invoked, as multiple situations suggest it. (Tt antagonizes the maternal estrogens, inducing a male foetus, Es have favourable effects in androgendependent cancer of the prostate, Es mediate the Sp activity of the smooth musculature, while Tt is involved in its Pp activity, etc. 6 The Tt ± Es antagonism probably also manifests itself at the level of the antagonistic sexual excitation centres Pp ± Sp. Thus, the ®rst response of a man (with a normal, ie dominant level of Tt) to an ef®cient sexual stimulation is the erection of the penis. Before ejaculation, lubricating¯uid is eliminated from the seminal vesicles. In the female (with a dominant level of Es), the ®rst response to an ef®cient sexual stimulation consists in the lubrication of the vagina, while the intumescence of the erectile genital organs occurs afterwards. In a succession of orgasms, the ®rst is the most intensely perceived by the male, while in the female it is the last which attains the highest intensity. 7In women, the Sp sexual excitation could be controlled by Es and the Pp sexual excitation by progesterone, a weak androgenic hormone. The libido is at its maximum in women during ovulation, when a concomitent secretion of the two hormones takes place. 6 The Pp sexual excitation in the male could be controlled by Tt, whereas the Sp sexual excitation could be controlled by a weak estrogenic stimulation. The administration of clomiphene (a weak estrogenic agonist) is useful as a sexual dynamic stimulation test in the male. Small amounts of Es are produced in the male through intervention of aromatasis, present in the brain, the testis and the skin (especially in the skin of the genital area), organs directly involved in the sexual excitation process. The administration of antiandrogens frequently induces gynecomastia by inversion of the activity ratio between Tt and Es. 6 Probably, the mixed Pp ± Sp sexual excitation process is possible by a positive feedback mechanism. Thus, this mechanism presumes the involvement of some protection system when the Pp ± Sp level of sexual excitation at...

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

“…I.G. Motofei proposed that the etiology of PE starting from a bihormonal model of normal sexual stimulation (Motofei, 2001b). The normal erection and ejaculation after sexual stimulation is mediated by the coordination between sympathetic and parasympathetic nerve system (Andersson & Wagner, 1995;Rowland et al, 2000).…”

The physiological basis of human sexual arousal: neuroendocrine sexual asymmetry

“…Not only is the role of gonadal hormones relevant, but so is the role of various types of sensory input. For example, some reports (Motofei, 2001) suggest that in men a strong androgen influence acting at cerebral level could transform the input from the somatically mediated penile shaft afferents into erogenous (parasympathetic) stimuli. The origin of this erotic stimulation is attributed (by the individual) to the somatosensory region of the penile shaft – the stimulation is both highly specific and very local.…”

“…Furthermore, in a succession of orgasms, men typically perceive the first as being the most intense, whereas women are more likely to perceive the last as being the most intense (Bear et al. , 1996; Motofei, 2001).…”

A dual physiological character for sexual function: libido and sexual pheromones

“…In humans, reproduction is therefore a sexual process, the reproductive sexual function implying the establishment of specific and complex affinities between men and women. Thus, human sexual behaviour encompasses a wide range of activities, such as strategies to find or attract partners (a psychosomatic construct), chemical interactions between individuals through sexual pheromones, and physical interactions during sexual intercourse under autonomic modulation of sexual hormones [2–4].…”

“…However, there is substantial progress apparent in the data presented in new reports on sexual function. A relatively recent theory is based on a morpho‐physiological duality concept, according to which sexual function has a double cerebral representation for all the mechanisms and manifestations involved [4]. It is an evolutionary theory that starts from unanimously accepted anatomical and physiological elements.…”