棉酚和V_A在水牛尿石症发生中的作用

EFFECTS OF GOSSYPOL AND VITAMIN A ON OCCURENCE OF UROLITHIASIS IN WATER BUFFALO

选用３４头无既往病史、９～１２月龄的未去势公水牛随机分为４组，采用二因子二水平４种处理，即：棉籽饼组、煮沸棉籽饼（煮饼）组、添加维生素Ａ组和不添加Ｖ＿Ａ组，对４组水牛进行了１２周人工诱病和预防试验。对血清中游离棉酚、结合棉酚、Ａ＿Ｖ的动态变化和组织中游离棉酚、结合棉酚含量及组织病理学改变进行了观察。试验结果：２４头试验牛中有１６头发生临床尿石症，其中煮饼组发病１２头，棉籽饼组发病４头；水牛血清及组织中均出现游离棉酚和结合棉酚蓄积，并引起心、肝、肾等实质器官的组织病理学变化；棉籽饼组与煮饼组间、添加与不添加Ｖ＿Ａ组间、表现与不表现临床尿石症间水牛血清中游离棉酚和Ｖ＿Ａ含量差异不显著（Ｐ＞０．０５），血清Ｖ＿Ａ含量保持在正常范围内；棉籽饼组水牛血清中结合棉酚及组织中游离棉酚、结合棉酚的含量显著高于煮饼组水牛（Ｐ＜０．０１）。试验结果表明：水牛饲喂棉籽饼能引起屎石症；水牛采食含游离棉酚１．３～２．５ｍｇ／ｇ的棉籽饼可造成实质器官的病理损害；棉酚对水牛肾脏的毒性作用所引起的病理变化是促成尿石症发生的预置因子；Ｖ＿Ａ在饲喂棉籽饼导致水牛尿石症的发生中作用不显著。

Twenty four buffaloes aged 9～12 months, uncastrated and with no past historyof disease, were randomly alloted to 4 groups.Each group was fed a different feedcombination of cottonseed meal or boiled cottonseed meal, with or without vitamin A(V_A)supplements using the two-way layout design.The dynamic fluctuation of free andbound gossypol and V_A in serum and the contents of free and bound gossypol in tissueswere tested and analysed. The histopathological change in parenchymal organs was alsoobserved. The results were as follows:16 of 24 buffaloes developed clinical urolithiasisduring the experiment;Free and bound gossypol gradually accumulated in serum andtissues;Various degrees of lesion in the heart,liver,kidney etc.appeared;The concen-trations of free gossypol and V_A in serum were not significant different between all 4groups, and the contents of V_A in serum were within normal range.The concentrationsof bound gossypol in serum, free and bound gossypol in tissues of buffaloes feddifferent kinds of cottonseed meal were significant different. We conclnded that feedingcottonseed meal or boiled cottonseed meal caused urolithiasis in buffalo, feeding cot-tonseed meal containing free gossypol 1.3～2.5mg/g induced histologic lesions inparenchymal organs, gossypol's toxic effect which caused pathologic picture in thekidney was a predisposing factor in the occurence of urolithiasis,vitamin A had noeffect on urolith formation in the experiment.