본 연구에서는 난소를 절제한 갱년기 장애 모델에서 Lactobacillus acidophilus YT1 투여가 혈중 지질 변화 및 골 형성에 미치는 영향을 알아보고자 하였다. 정상대조군(NC), 난소비절제대조군(Sham), 난소절제대조군(OVX), 양성대조군(PC), 1×10<SUP>6</SUP> CFU/kg b.w.(Low), 1×10<SUP>7</SUP> CFU/kg b.w. (Medium), 1×10<SUP>8</SUP> CFU/kg b.w.(High)로 분리하여 8주간 각 농도에 맞게 투여하며 사육하였다. 8주간의 L. acidophilus YT1 투여로 난소절제에 의한 체중증가, 식이효율 및 체온조절장애가 개선되었음을 확인하였다. 또한 난소절제로 인해 증가한 혈중 지질이 감소하였으나, 혈중 estradiol 농도와 자궁조직 내 c-fos, c-jun 단백질 변화는 나타나지 않았다. 골밀도와 골의 형태학적 계측을 측정한 결과에서는 난소절제로 인해 감소한 골밀도, Tb.N이 L. acidophilus YT1 투여로 회복되었음을 확인하였다. 정강이뼈에서 ER1, ER2, RANKL 및 OPG 유전자 발현량을 측정한 결과에서는 L. acidophilus YT1 투여가 ER1에는 영향을 미치지 않으나 난소절제로 감소한 ER2, OPG 유전자 발현량을 증가시키고, RANKL 유전자 발현량은 감소시켜 골대사에 긍정적인 효과가 있었음을 확인하였다. 따라서 본 연구에서는 L. acidophilus YT1이 에스트로겐 결핍으로 인한 갱년기 증상 개선에 긍정적인 영향을 주는 것을 확인하였고, 이를 활용한 기능성 소재 개발이 가능할 것으로 기대된다.
This study was undertaken to determine the effect of Lactobacillus acidophilus YT1 on serum lipid levels and bone formation in ovariectomized rats. Animals were randomly allocated seven groups; the normal control(NC), the sham-operated control (Sham), the ovariectomized (OVX), the OVX+1 mg/kg body weight (b.w.) of estradiol (OVX+PC), the OVX+1×10<SUP>6</SUP> CFU/kg b.w. of L. acidophilus YT1 (OVX+Low), the OVX+1×10<SUP>7</SUP> CFU/kg b.w. of L. acidophilus YT1 (OVX+Medium), and the OVX+1×10<SUP>8</SUP> CFU/kg b.w. of L. acidophilus YT1 (OVX+High) groups. All rats were provided with supplemented experimental diets and water for 8 weeks. Body weight gain, food efficiency rate, and abdominal temperatures were significantly lower in the OVX+PC, OVX+L. acidophilus groups (OVX+Low, OVX+Medium, and OVX+High groups) than in the OVX group. Serum lipid content analysis showed that the total cholesterol, triglyceride, and low density lipoprotein cholesterol levels were significantly lower in the OVX+PC, and OVX+L. acidophilus groups than in the OVX group, whereas high density lipoprotein cholesterol levels in the OVX group and the other groups were not significantly different. Serum estradiol levels were significantly lower in the OVX group than in the NC and Sham groups, but L. acidophilus supplementation had no observed effect on serum estradiol levels. Bone morphometric markers (BMD, BV/TV, Tb.N) were significantly higher in the OVX+PC and OVX+High groups than in the OVX group. In addition, L. acidophilus supplementation increased the mRNA expression of ER2 and OPG, and decreased the mRNA expression of RANKL in tibia as compared with those observed in the OVX group. These results suggest L. acidophilus YT1 might offer a means of ameliorating menopause associated symptoms such as osteoporosis, dyslipidemia, and face flushing.