While we're talking about sex steroids, it might be useful to note the following (I'm sure that some of out threadsters will have comments):
Wednesday March 11 6:04 PM EST
Humans Produce Pheromones
NEW YORK (Reuters) -- A study of armpit secretions from women suggests the answer to a tantalizing question --
humans do indeed produce pheromones, chemical signals that can affect the physiology and perhaps the behavior of those
around them.
Writing in the journal Nature, researchers at the University of Chicago (UC) say their study "provides definitive evidence"
that human pheromones do, indeed, exist.
In the study, Kathleen Stern and Martha K. McClintock of the department of psychology at the university asked one group
of nine women between the ages of 20 to 35 (the donors) to wear a pad in their armpit for at least eight hours. The
researchers then removed the pads and applied them daily under the noses of 20 women in the same age group.
The UC team found that the odorless compounds collected from the armpits of the donors in the late follicular phase of their
menstrual cycle sped up the preovulatory surge of luteinizing hormone -- and shortened the menstrual cycles -- of the
second group of women.
Also, the researchers say, they found that other compounds collected later in the menstrual cycle from the same donors (at
ovulation) had the opposite effect: they delayed the luteinizing-hormone surge of the recipients and lengthened their
menstrual cycles.
"By showing in a fully controlled experiment that the timing of ovulation can be manipulated, this study provides definitive
evidence of human pheromones," write the researchers.
Scientists first suspected the existence of human pheromones when they discovered that women living together sometimes
develop synchronized menstrual cycles. A similar phenomenon of ovarian synchronicity has been documented in
experimental rats. The synchronicity in rats was found to be triggered by the passing back and forth of two different
pheromones: one that shortens the menstrual cycle, another than lengthens it.
McClintock, a professor of psychology at UC, says that the data from the study "-demonstrate that humans have the
potential to communicate pheromonally, either by using an unidentified part of the main olfactory system, or perhaps with a
sixth sense, with its own unique pathway." She points out that since pheromones appear to affect the length of the menstrual
cycle, they might have possible uses in a clinical setting to prevent pregnancy or perhaps even treat infertility. SOURCE:
Nature (1998;392:177-179) 2 |
