title: The role of long-term loading of cholesterol in renal crystal formation.
abstract: We studied the effects of cholesterol load on urinary stone in rats receiving a standard diet or a high fat diet. Sixty male rats were randomized to two groups and were fed either a standard diet (SD group) or a high fat diet (HFD group) for 8 weeks. Then the two groups were further divided into four groups. SD group, HFD group, SD + EG group (with standard diet + ethylene glycol administration for two weeks), and HFD + EG group (with high fat diet + ethylene glycol administration). The starting date of EG administration was considered to be week 0. Twenty-four-hour urine samples were collected in week 0, week 1, and week 2, and oxalate excretion and citrate excretion were measured by capillary electrophoresis analyzer The excretion of phosphorus, magnesium, and creatinine for 24 hours was measured using an automated analyzer Serum sodium, potassium, chloride, calcium, phosphate, magnesium, creatinine, total cholesterol, triglyceride, HDL-cholesterol and glucose were determined using an automated analyzer The kidney tissues were obtained to perform hematoxyline-eosine staining and Pizzolato's staining to detect oxalate-containing crystals. The average body weight in HFD groups and HFD + EG group in week 0 was significantly higher than that of SD group and SD + EG group. The calcium oxalate crystal deposition was not observed in all groups in week 0. HFD + EG group in week 1 had sporadically calcium oxalate crystal deposition in renal distal tubular cells and tubular lumens. In week 2, the number of crystal deposition in HFD + EG group was increased remarkably. The crystals were slightly observed in SD + EG group in week 2. The excretion of urinary calcium and phosphate in HFD group and HFD + EG group was significantly higher than that of the SD group and SD + EG group in week 0. The amount of urinary citrate excretion in the SD group and SD + EG group showed a significantly higher value compared with that of the HFD group and HFD + EG group in week 0. The level of serum total cholesterol in the HFD group and HFD + EG group was higher compared to that in the SD group and SD + EG group. The serum triglyceride level was not significantly different in the four groups in week 0. Interestingly, the level of triglyceride of EG administration groups (SD + EG and HFD + EG group) was significantly higher than that in EG no-administration groups (SD group and HFD group) in week 1 and week 2. The serum glucose level in the HFD group and HFD + EG group was significantly higher than that in the SD group and SD + EG group in week 0. In week 2, the glucose level of EG administration groups (HDF + EG group and SD + EG group) was significantly lower than that of EG no-administration groups (HFD group and SD group). In conclusion, this result suggested that long-term loading of cholesterol could increase renal calcium stone formation.
authors.affiliation: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi, Japan. yasunori2009@gmail.com
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Itoh
authors.forename: Mugi
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Niimi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Usami
authors.forename: Shuzo
authors.initials: S
authors.lastname: Hamamoto
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Masahito
authors.initials: M
authors.lastname: Hirose
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okada
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yasui
authors.forename: Keiichi
authors.initials: K
authors.lastname: Tozawa
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kohri
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000378:metabolism*; D003460:Crystallization; D007668:Kidney / Q000378:metabolism*; D007669:Kidney Calculi / Q000209:etiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D002784:Cholesterol