Study On The Struvite And Magnesium Potassium Phosphate Urolithiasis In Goat

Urolithiasis is among the most important urinary tract problems of domestic animals. Magnesium ammonium phosphate (MAP), also named as struvite, is popular in feeder steers and lambs, especially in castrated ruminants and male animals. This disease could cause fatal harm once the obstruction of calculi located in urinary tract. There are different views in preventing and controlling urolithiasis for the complex causes and pathogenesis, and the key way of solving this trouble is discovery the pathogenesis of urolithiasis. The leading study of calcium oxalate was focused on two aspects. Of importance were investigations on the influence of diet on urinary stone formation. Another emphasis of research was investigation of the crystallization process: supersaturation, crystal growth and aggregation are important steps in urinary stone formation. Of great importance in the formation of urinary stones are inhibitors (inhibitory activity) . The last 15 years have shown an increasing turning toward the importance of cellular alterations and supersaturation and their relation to stone formation. To ruminants, the struvite study has been carried out in clinical survey, composition and construction of calculi and crystals, causes and prevention and cure. Magnesium potassium phosphate (MKP) was isomorphous analogues with MAP and also described as a new biological calculi component in water buffalo feeding with cottonseed meal diet. Though dietary mineral imbalance and high concentrates were considered as major factors of urolithiasis in ruminants, how do two factors contribute to the occurrence of calculi is still kept unknown or disagreement. We know a little about ruminant urolithiasis as compared with the study of calcium oxalate, and many aspects of this disease need further study to learn more about it and prevent it unequivocally. So, the experiment was carried out based on inducing struvites (MAP, MKP) and the pathogenesy of urolithiasis was investigated from such aspects as supersaturation of urine, damage of kidney cells and tissues, inhibitory activity of urine. Testâ… Effect of high intake of magnesium on urolithiasis in wether lambs. Theeffect of high intake of magnesium on urolithiasis in feedlot wethers was compared with high potassium and phosphate under the Chinese traditional feeding style with cotton seed meal and rice straw diet. Eighteen wethers aged from 3-4 months were randomly allotted to group A, B, C. After for two months feeding with cotton seed meal and rice straw diet, KH2PO4 and K2HPO4 were provided by drinking water to increase the intake of P and K of goats in group B, and MgO was provided by drinking water to increase the intake of Mg of goats in group C, group A was designed as control group without additional mineral supplemented. Blood and urine samples were collected to analyze the concentration of P, K, Mg, Ca. The incidence of urolithiasis was recorded. The composition of urinary sediments and stones was studied by chemical qualitative analysis, X-ray diffraction, X-ray energy dispersive spectrometry (EDS) and Fourier transform infrared (FTIR) spectroscopy. The results shoed that 6 urolithiasis cases were found in group C after drinking water contains MgO, each one urolithiasis case was found in group B and A respectively, the incidence of urolithiasis in group C was significantly higher than group A and B(P<0.05) . Synthetic analysis showed that the chemical composition of calculi was mainly composed of magnesium ammonium phosphate and partly composed of potassium magnesium phosphate. The plasma Mg, P and urine Mg, P, K of three groups in days 60 were significantly higher than days 0(P<0.05); Additional P, K via drinking water further increased urine P, K (P<0.05) but not to plasma P, K in group B; Additional Mg via drinking water further increased plasma Mg in group C(P<0.05) . In conclusion, urolithiasis is induced by high intake of magnesium in goat feeding with cotton seed meal and rice straw diet and high magnesium is a more important dietary factor of urolithiasis in wether when compared with high P, K. Additional MgO via drinking water cooperating with cotton seed meal and rice straw diet could be consider as a model of inducing urolithiasis in goat.Testâ…¡Variation of crystals composition during course of onset of urolithiasis in goat. Variation of crystals composition was observed during course of onset of urolithiasis in goat to approach the relation between crystals and lithogenesis. We aimed at learning more about the pathogenesis and its latent value of forecasting lithogenesis. Urinary sedimentary crystals were collected and divide into group A (crystals at the stage before stone formation) , group B (crystals at the stage after stone formation) and group C (crystals emerged in stone under scan electric microscope) . The composition of crystals was studied by chemical qualitative analysis, X-ray diffraction, X-ray energy dispersive spectrometry (EDS) and quantitative analysis. In group A, EDS data from crystals with difference size at scan was divide into bigger and smaller crystals to study the variance of compositions. It was found that P, K, Mg and NH₄⁺ showed positive in samples from group A and B. X-ray diffraction analysis showed that crystals of group A were approximated to magnesium ammonium phosphate (MAP) and crystals of group B were approximated to magnesium potassium phosphate (MKP) . Content of MAP in group A was significantly higher than group B and MKP in group B was significantly higher than group A (P<0.05). Composition of crystals in group C was nearly unitary MKP. The smaller crystals were mainly composed of MAP and the bigger ones were mainly composed of MKP in group A, but crystals in group B were mainly composed of MKP. It was concluded that crystals composition were composed of MAP and MKP, the mainly composition of urinary sedimentary crystals was varied from MAP to MKP after lithogenesis and MAP in crystals participated to calculi during this procedure. The appearance of MKP crystals scattered disorderly in stone were help to understand the fragile character of ruminant urinary calculus. The contents of MAP and MKP of crystals with difference size before and after stone formation should be help to understand lithogenesis and its prediction.Testâ…¢Dynamic changes of content of relative ions in serum and urine during occurrence of urolithiasis. The dynamic changes of content of relative ions were investigated in serum and urine during occurrence of urolithiasis, we aimed at learn more about the variation of urinary supersaturation status and the relation between lithogenesis and kidney function of this procedure. Urolithiasis was induced in 6 wether lambs by feeding cottonseed meal diet and adding MgO in drinking water. The content of inorganic phosphorous, calcium, magnesium, potassium, sodium, chlorine and ammonium in serum and urine were determined during the different phases of lithogenesis. It was found that serum phosphorous and magnesium got a significant increase when goats were fed with cotton seed meal and rice straw diet. Urolithiasis was induced successfully in lambs treated with MgO and serum magnesium and potassium increased significantly in anuretic goats but a significant decrease was found in serum phosphorous, sodium and chlorine. No significant changes were detected in serum calcium and ammonium during this procedure. Urine phosphorous, magnesium, potassium and ammonium decreased significantly in lambs feeding cottonseed meal diet and further decrease was observed after the occurrence of lithogenesis. Urine sodium increased significantly in the initial period of anuresis and further enhanced several days later. The content of urine chloride decreased gradually during stone formation and urine calcium only decreased significantly after anuresis. Conclusion, goats got a hyperkalemia, hyponatremia and hypochloraemia after the occurrence of urolithiasis, which suggested the acute renal failure in calculous lambs and this disorder aggravated with the last of anuresis. The decreased contents of urine phosphorous, magnesium, potassium and ammonium contributed to the formation of crystals, especially to calculi, which suggested that urinary supersaturation status decreased after the occurrence of urolithiasis.Testâ…£Changes of urea, creatinine and urine protein during occurrence of urolithiasis. The relationship between lithogenesis and metergasis of kidney was investigated by monitoring dynamic changes of urea, creatinine and urine protein during occurrence of urolithiasis. Urolithiasis was induced in 6 wether lambs by feeding cottonseed meal diet and adding MgO in drinking water. The content of urea and creatinine in serum and urine were determined during the different phases of lithogenesis, so did urine protein, and the ration of serum urea to serum creatinine: was also calculated to evaluated the function of kidney. It was resulted that urea and creatinine in serum got a significant increase but significant decrease was observed in urine after the occurrence of urolithiasis in goat. Before the occurrence of urolithiasis no significant change was found in urine urea, urine creatinine and serum creatinine, only serum urea got a significant increase after cotton seed meal and rice straw diet feeding. The ration of serum urea to serum creatinine increased significantly after cotton seed meal and rice straw diet feeding but decreased significantly after the occurrence of lithogenesis. Urine protein got a significant increase after cotton seed meal and rice straw diet feeding but decreased significantly at the initial stage of lithogenesis, then a significant increase was found several days later of anuresis. In conclusion, cottonseed meal diet could induce renal insufficiency in goat and lithogenesis induced by high magnesium intake could result in renal failure, the occurrence of urolithiasis induced by high magnesium intake could relate to the lesion of kidney which should originate from higher excretion of urine magnesium.Testâ…¤Evaluation of urinary supersaturation during the onset of urolithiasis in goats. Supersaturation status of urine was investigated to understand the biomineralization processes involved in the pathogenesis of urinary stone formation of goat. Urolithiasis was induced in 6 wether lambs by feeding with cottonseed meal diet and adding MgO in drinking water. The supersaturation states of urine were evaluated during the onset of urolithiasis in goats by dynamical observation of changes of urinary crystals, urinary conductivity, activity products (AP) and relative supersaturation (RSS) of MAP and MKP. The experiment was lasted as four phases, period at the end of pre-testing was designed as phaseâ… , days 15-60 of experiment as phaseâ…¡, the initial stages of dysuria as periodâ…¢, days 2-5 after dysuria as periodâ…£. It was found that urolithiasis occurred in all six goats, main compositions of uroliths were MAP with a small quantity of MKP. Crystals in phaseâ…¡were also mainly composed of MAP with a small quantity of MKP., but crystals in phaseâ…£were mainly composed of MKP. Crystals emerged largely with different size in urine in phaseâ…¡, Crystals emerged largely with different size in urine of periodâ…¡and basically disappeared in periodâ…¢, but small crystal could be found again in urine of periodâ…£with a significant lower quantity than that in phaseâ…¡(P<0.05). Both AP of MAP and MKP, RSS of MAP and MKP and urinary conductivity of periodâ…¢,â…£were significantly lower than phaseâ… andâ…¡(P<0.05) . In conclusion, the supersaturation status of urine was decreased after the formation of calculi, and its changes could be help to understand the question how does crystal convert to calculi.Testâ…¥Changes of cast-off cells and casts of urine during occurrence of urolithiasis. The changes of cast-off cells and casts of urine were investigated during occurrence of urolithiasis, and the relationship of injury of kidney and urolithiasis induced by high intake of magnesium was discussed. Urolithiasis was induced in 6 wether lambs by feeding cottonseed meal diet and adding MgO in drinking water. Quantitive changes of cast-off cells and casts of urine in different phases of experiment were monitored. The result showed that small amounts of tubules epithelium was observed in urine of goat after cotton seed meal and rice straw diet feeding. At the initial phase of occurrence of urolithiasis induced by MgO treatment, cast-off cells of Tubules epithelium and pelvis epithelium with small amounts of cast were observed in urine from bladder, at this phase, the nephric epithelium with erythrocyte and leukocyte were founded in urine of dripping from penis. Several days after the occurrence of urolithiasis amounts of cast-off cells and casts got a further increase. Conclusion, high intake of magnesium could provoke the shedding of nephric epithelium, this condition contributed to the change of kidney function and depressed the capability of calculous inhibition of subject. The cast-off cells also offered a convenience of calculous nucleation and promoted the occurrence of urolithiasis in goat. Testâ…¦Study on histopathology of kidney in lithogenous goats. Thehistopathology of kidney in lithogenous goats was investigated to learn more about the pathogenesis of urolithiasis and the effect of calculi on kidney. 5 goats without urolithiasis were designed as control group and 6 goats with urolithiasis as lithogenous group. Pathological changes were investigated by necropsy, light microscope, electron microscope and flow cytometry. The result showed that calculi was mainly located at bladder and urethra and provoked inflammation of these two locations. Calculus particle was observed in kidney medulla of lithogenous goat by light microscope. Glomcrulus showed swell or shrink and proteinaceous leakage could be observed in capsular space. The degeneration and defluxion of renal tubular epithelial cell could be observed and cast, calculi and cast-off cells also could be observed in lumens. Haemorrhage, edema and slight inflammatory cells infiltration could be observed in renal interstitium. The homologous pathological changes were observed in kidney by electron microscope. The necrosis rate of kidney tissue in lithogenous group was significantly higher than that in control group (P<0.05), no significant difference was found in apoptosis rate of kidney tissue in goats of two groups. In conclusion, the kidney tissue was damaged with necrotizing change after the occurrence of urolithiasis in goats.Testâ…§Effect of high urinary magnesium on inhibitory activity of crystallization in vitro. Effect of high urinary magnesium on inhibitory activity of crystallization was investigated and changes of inhibitory activity before and after urinary stone formation were also investigated in vitro. In experiment, magnesium, ammonium and phosphate ions together or solely magnesium ion were added to urine, and quantity of crystal and activity of product of magnesium ammonium phosphate in urine samples were determined. It was found that activity of product of magnesium ammonium phosphate got a significant decrease under high levels ions treatments and quantity of crystal got a significant increase at same time. In conclusion, high magnesium could depress inhibitory activity of crystallization in urine during the struvite formation and the inhibitory activity decreased significantly after urinary stone formation.