title: Effect of short-term fasting on hepatic steroid hormone metabolism in cows.
abstract: In the present study, the effect of 4-day fasting on steroid hormone metabolism in the liver and secretion of LH was examined in cows. Six non pregnant, dry Holstein cows were used. The estrous cycle was synchronized in all cows using CIDR-Ovsynch. Cows were allocated to a control group (n=3) and a fasting group (n=3). In the fasting group, cows were fasted for four days from day -4 to day -1 (day 0=day of 2nd GnRH injection) but otherwise were fed ad libitum. The experiment was repeated in a crossover design after an interval of about one month. The peripheral progesterone (P(4)) concentration in the fasting group was significantly higher than in the control group on day -1 and 0. The peripheral estradiol-17β concentration in the fasting group was also significantly higher than in the control group on day -1 and 0. The portal vein P(4) concentration in the fasting group was significantly higher than in the control group. On day 0, there was no difference in LH secretion between groups. The mean percentages of lipid droplets in liver cells in the fasting group were significantly higher than in the control group on day 0. These results suggest that short-term fasting leads to reduced hepatic steroid hormone metabolism by accumulation of fat in the liver, which causes high peripheral steroid hormone concentrations.
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252–0880, Japan.
authors.forename: Mamiko
authors.initials: M
authors.lastname: Ono
authors.forename: Tadatoshi
authors.initials: T
authors.lastname: Ohtaki
authors.forename: Kouichi
authors.initials: K
authors.lastname: Tanemura
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ishii
authors.forename: Gen
authors.initials: G
authors.lastname: Watanabe
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Taya
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Tsumagari
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism*; D018592:Cross-Over Studies; D004958:Estradiol / Q000097:blood*; D004973:Estrus Synchronization; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D008099:Liver / Q000378:metabolism*; D007986:Luteinizing Hormone; D011374:Progesterone / Q000097:blood*
chemical_list: D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone