Vol. 278, Issue 4, R863-R869, April 2000
Elevation of tail skin temperature in ovariectomized rats in
relation to menopausal hot flushes
Tsunefumi
Kobayashi,
Mizuho
Tamura,
Minoru
Hayashi,
Yasuhiro
Katsuura,
Hirofumi
Tanabe,
Tomohiro
Ohta, and
Keiji
Komoriya
Pharmacological Research Department, Teijin Institute for
Bio-Medical Research, Hino, Tokyo 191-8512, Japan
Menopausal hot flushes (HFs), which
manifest as an increase in skin temperature, most frequently occur
after menopause and cease with the passage of time. We designed this
study to elucidate the characteristics of the elevation of tail skin
temperature (TST) in ovariectomized (OVX) rats, which is relevant to
human symptoms of HFs. First, we measured TST and rectal temperature (RT) and investigated the time course of their changes up to 20 wk
after ovariectomy. The TST in OVX rats (28.4 ± 0.3°C) was
significantly (P = 0.0035) elevated from 2 to 7 wk after the
ovariectomy compared with that in sham-operated (Sham) rats (27.0 ± 0.2°C), whereas the RT in OVX rats was elevated from 8 to 20 wk. We
next examined the therapeutic effects of estradiol (E2) on
the elevation of the TST by continuous subcutaneous infusion.
E2 treatment (1.0 µg/day) completely (P = 0.0232)
inhibited the elevation of the TST (28.4 ± 0.3°C for Sham rats,
29.3 ± 0.3°C for OVX rats, 28.2 ± 0.4°C for OVX + E2 1.0 µg/day rats). These results demonstrated that the
elevation of TST in OVX rats was exhibited soon after the estrogen
removal and diminished with time and that it was normalized with
continuous E2 replacement. These characteristics are
similar to the symptoms of menopausal HFs in women.
estradiol; rectal temperature; body temperature; thermoregulation
