title: Study on precipitation of struvite and struvite-K crystal in goats during onset of urolithiasis.
abstract: To learn more about the biomineralization process of struvite in ruminants, a seldom noticeable crystal, struvite-K, was investigated in six goats in which urolithiasis was induced by feeding a cottonseed meal and rice straw diet supplemented with MgO. The compositions of crystals and calculi were studied by chemical qualitative analysis and X-ray energy dispersive spectrometry (EDS). The activity product (AP) and relative supersaturation (RSS) of magnesium ammonium phosphate (MAP) and potassium magnesium phosphate (MKP) were calculated to compare the difference of crystals formed in this process. The results showed that calculi consisted of MAP with a little MKP. Crystals in the urine consisted of MAP and MKP before stone formation, but crystals in urine after stone formation mainly consisted of MKP. The AP and RSS of MAP and MKP significantly decreased after stone formation. It was concluded that MAP and MKP may coexist in the crystals of urine before struvite calculi formation but MKP did not precipitate to struvite calculi and was separated out as crystal sedimentation of urine. The changes of crystallization of MAP and MKP contributed partially to the supersaturation status of MAP and MKP during struvite stone formation.
authors.affiliation: Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Sun
authors.forename: Jin-Yong
authors.initials: JY
authors.lastname: Wang
authors.forename: Ke-Chun
authors.initials: KC
authors.lastname: Zhang
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Wang
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000378:metabolism; D002415:Cats; D004283:Dog Diseases / Q000378:metabolism; D004285:Dogs; D015511:Goat Diseases / Q000139:chemically induced / Q000378:metabolism* / Q000652:urine; D006041:Goats; D017616:Magnesium Compounds / Q000008:administration & dosage / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology / Q000652:urine; D008277:Magnesium Oxide / Q000008:administration & dosage / Q000494:pharmacology; D010710:Phosphates / Q000302:isolation & purification* / Q000378:metabolism / Q000652:urine; D017680:Potassium Compounds / Q000008:administration & dosage / Q000494:pharmacology; D000069877:Struvite; D052878:Urolithiasis / Q000139:chemically induced / Q000378:metabolism / Q000652:urine / Q000662:veterinary*
chemical_list: D017616:Magnesium Compounds; D010710:Phosphates; D017680:Potassium Compounds; D008277:Magnesium Oxide; D000069877:Struvite; C042171:potassium magnesium sulfate