CONTINUOUS MEASUREMENT BY RADIO-TELEMETRY OF VAGINAL pH DURING HUMAN COITUS

Abstract

The use of the pH-pill has allowed continuous monitoring of vaginal pH during human coitus. In the case of a couple of normal fertility, there was an immediate buffering by seminal plasma so that the vaginal pH changed in 8 sec from pH 4\m=.\3to pH 7\m=.\2.In the case of a couple of low (male) fertility, the immediate effect of the arrival of semen in the vagina was a change from pH 3\m=.\5to pH 5\m=.\5.A similarly small change in pH occurred when the seminal volume of a fertile male subject had been depleted, by repeated ejaculation, to 1 \ m=. \ 5ml. At this pH (5\m=.\5),spermatozoa are generally immobilized.It has been possible to alter normal fertility, as judged by postcoital tests for sperm motility, by the introduction of a pH 3\m=.\6buffer solution into the vagina before coitus. In this latter experiment, the vaginal pH immediately after ejaculation was 5\m=.\0 and, after 2 hr, had reached pH 5\m=.\4.These results in vivo suggest that the vagina is not the hostile environment hitherto imagined, since the normal ejaculate readily overcomes the vaginal acidity by its powerful buffering action. Low seminal volume, with or without a concomitantly low sperm count, and artificial changes in vaginal environment by buffer solutions may affect fertility.

Role of Semen in Modulating the Female Genital Tract Microenvironment – Implications for HIV Transmission

“…It has long been known that following ejaculation, semen raises the normally acidic pH of vaginal fluid to 7.0 or higher within 30 s, and this neutralization of the vaginal lumen can persist for at least 2 hrs. 61,62 The buffering capacity of semen may help to maintain conditions that are conducive to HIV-1 stability and infection. [63][64][65][66] 72 Furthermore, complement activation in seminal fluid generates C3 cleavage and augments HIV-1 infection in epithelial cells.…”

A journey through two lumens!

“…48 Masters 49 had previously made similar measures, but he placed the electrode blindly into the vagina and did not undertake any statistical analysis of his data. A study using a radiotelemetry pH electrode placed high up in the fornix in just one subject 50 did not find any change in pH during coitus to orgasm. As a result of this, they questioned the hypothesis that the lubrication fluid formed on the surface of the vagina at arousal was a transudate of plasma as they assumed that the pH should have become neutralised to pH 7.…”

Hyaluronidase-Sensitive Nanoparticle Templates for Triggered Release of HIV/AIDS Microbicide In Vitro

“…The f 1 and f 2 values (46) are calculated using Eqs. (9) and (10), respectively, and shown in Table III. The results indicated that there was a significant difference between the HA degradation and drug release kinetics from HA-gel and HANPs either in the presence and absence of HAase.…”

“…The CV pH is also significantly higher (6 to 7) during the menstruation cycle (9). During sexual intercourse, the CV fluid is neutralized (pH 7 to 7.2) by the alkaline pH (7.2 to 8) of human semen within 8 s of arrival of seminal fluid (8,10). A small amount of semen is sufficient to neutralize the acidic pH of CV fluid due to its higher buffer capacity (8).…”