Premium
Deprivation of plasma estradiol level affects circadian rhythms of body core and tail skin temperature in female rats
Author(s) -
Marui Shuri,
Nagashima Kei
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.993.8
Subject(s) - core (optical fiber) , medicine , endocrinology , circadian rhythm , ovariectomized rat , core temperature , skin temperature , thermoregulation , chemistry , zoology , biology , estrogen , materials science , biomedical engineering , composite material
Purpose We aimed to assess the effect of estradiol on daily changes of thermoregulatory responses of the tail vasculature in ovariectomized rats. Methods Female Wistar rats (n=10, age of 8‐12 wk) were bilaterally ovariectomized, and placed a telemetry device for the measurements of body core temperature (T core ) and spontaneous activity (ACT) in the abdominal cavity. Temperature of the tail surface (T tail ) was estimated by thermography. Two silicon tubes containing 17β‐estradiol (E 2 , 50mg) were subcutaneously placed in one group (n=5, E 2 (+)), and empty tubes were placed in the other group (n=5, E 2 (‐)). The tubes were removed 10 days after the surgery. T core , ACT, and T tail were measured a day before and 14 days after the removal of the tubes (PRE and Day 14, respectively). Regression analysis was conducted for the relationship between the daily values of T core and T tail . Results On the PRE, T core was higher (P<0.05) in the E 2 (‐) group than in the E 2 (+) group at 12:30‐17:00 (37.2±0.2°C and 36.5±0.2°C, respectively). T tail was higher (P<0.05) in the E 2 (‐) group than the E 2 (+) group at 20:00‐0:30 (33.4±0.3°C and 31.2±0.6°C, respectively). The regression slope for T tail and T core was greater (P<0.05) in the E 2 (‐) group than in the E 2 (+) group on the PRE (1.41±0.34 and 0.60±0.16, respectively). On Day 14, in the E 2 (‐) group, circadian rhythms of T core and T tail remained unchanged from those on the PRE. T core and T tail were higher than those on PRE at 14:30‐18:30 and 19:00‐18:30, respectively. The regression slope was greater (P<0.05) than that of the PRE. Conclusion A reduction of estradiol affects circadian rhythms of T core and T tail . Moreover, a lack of estradiol may decrease the ability in thermoregulatory response of the tail vasculature.