Evaluation of hot-flash model rats induced by bilateral oophorectomy and tamoxifen administration / 中国实验动物学报

ABSTRACT

Objective To explore the animal model of syndrome used in the study of hot flash phenomenon in women.Methods Twenty-four female SD rats were divided randomly into three groups:Con group,Ovx group,and tamoxifen group(n = 8 rats per group).Hot flashes were induced by bilateral oophorectomy and intragastric tamoxifen 10 mg/(kg·d),respectively.Open-field activity,anal temperature,and body surface infrared thermograms were detected on model days 14 and 28.The rats were then killed on day 29 and their uteruses were removed,weighed,and sectioned.Blood estradiol and catecholamine levels were determined by enzyme-linked immunosorbent assay.Gene expression levels of adrenal sex hormone synthetases(Star,Cyp11a1,Cyp17a1,Cyp19a1,Por,Hsd3b2,Hsd17b1)and catecholamine synthetases(Th,Ddc,Dbh,Pnmt)in the adrenal medulla were detected by reverse transcription-polymerase chain reaction.Results Rat body weight was significantly higher in the Ovx group compared with Con group(P<0.01),while body weight increased slowly in the tamoxifen group.The maximum body surface temperature was significantly decreased on day 28 in the Ovx group(P<0.01),the difference between the maximum and minimum abdominal temperatures was significantly increased on day 14(P<0.05),the difference between the maximum and minimum temperatures on the back was significantly increased on day 28(P<0.01),and the open-field activity was decreased(P<0.01).Compared with the sham operation group,the maximum body surface temperature in the tamoxifen group was significantly decreased(P<0.01)but the open-field activity was increased(P<0.01).The uterine index was significantly decreased in both models(P<0.01).Estradiol levels were significantly decreased(P<0.01)and NE and epinephrine were also significantly decreased in the Ovx group compared with Con group(P<0.05),and β-EP was also significantly decreased in Ovx group(P<0.05).Adrenal Cyp11a1 gene expression was significantly increased(P<0.05)while Cyp17a1 and Hsd17b1 gene expression levels were significantly decreased(P<0.05)in bilateral ovariectomized rats compared with Con group.Compared with Con group,gene expression levels of Star and Por were significantly increased(P<0.01)while Cyp17a1 gene expression was significantly decreased(P<0.01)in the tamoxifen group,and Pnmt gene expression was significantly down-regulated in Ovx group(P<0.01).Conclusions Bilateral ovariectomized rats can be used for the study of perimenopausal hot flashes,which resemble kidney Yang and Yin deficiency in traditional Chinese medicine.