AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 6 1126-R1136, Copyright © 1986 by American Physiological Society
Menstrual cycle and sensitivity of human fallopian tube to prostaglandins
M. Nozaki and Y. Ito
The shapes and frequencies of spontaneous contractions of circular muscle
strips of the human oviduct differ during the menstrual cycles. However,
under given conditions, the frequency and amplitude of the contractions
were continuously reduced during perfusion with Krebs solution. In the
presence of prostaglandin (PG) synthesis inhibitors or an antagonist, a
gradual and continuous reduction was no longer observed, and low
concentrations (10(-15)-10(-10) M) of PGE2 markedly suppressed the
amplitude and frequency of the spontaneous contractions. The highest
sensitivity of smooth muscle cells to PGE2 was observed during the
periovulatory phases. Spontaneous prepotentials followed by slow waves were
observed, and the latter potentials triggered contraction of the tissue.
PGE2 (10(-14)-10(-12) M) inhibited, and PGF2 alpha (10(-9)-10(-7) M)
enhanced the frequency of these slow waves. The amount of PGE series
released from the tissues was twice of PGF series. These results suggest
that endogenous prostaglandins play a physiological role in the transport
of ovum in the human fallopian tube as a result of the regulation of
spontaneous membrane and mechanical activities.
