Female Ejaculation and the G-Spot (10 page)

A 2007 study on two women involved ultrasound, endoscopy, and biochemical analysis of fluid. The ejaculate was compared to pre-orgasmic urine from the same woman, and also to published data on male ejaculate. In both women, higher levels of PSA, PAP, and glucose but lower levels of creatinine were found in the ejaculate than the urine. PSA levels were comparable to those in males.
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Source of fluid

One very practical objection relates to the reported volumes ejaculated since this fluid must be stored somewhere in the pelvis, of which the urinary
bladder
is the largest source. The actual volume of the para-urethral tissue is quite small. By comparison, male ejaculate varies from 0.2–6.6 mL (0.04–1.3 tsp) (95%
confidence interval
), with a maximum of 13 mL (2.6 tsp).
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Therefore claims of larger amounts of ejaculate are likely to contain at least some amount of urine. The eleven specimens analyzed by Goldberg in 1983,
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ranged from 3–15 mL (0.6–3.0 tsp).
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One source states that Skene's glands are capable of excreting 30–50 mL (6–10 tsp) in 30–50 seconds,
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but it is unclear how this was measured and has not been confirmed. One approach is to use a chemical like
methylene blue
(or drugs like Urised which contain it) so that any urinary component can be detected.
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Belzer showed that in one woman he studied, the dye was found in her urine, but not her orgasmic expulsion.
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PAP and PSA have been identified in the para-urethral tissues, using biochemical and immunohistochemical methods, suggesting that the ejaculate likely arises from the ducts in these tissues, in a manner homologous to that in the male.
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Another marker common to the prostate/para-urethral tissue in the both sexes is Human Protein 1.
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PSA occurs in urine, and is elevated in post-orgasmic samples compared to pre-orgasmic. Simultaneous collection of ejaculate also showed PSA in both urine and ejaculate in all cases, but in higher concentration in the ejaculate than in the urine.
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