Mello J R B
Department of Pharmacology, Federal University of Rio Grande do Sul, R. Sarmento Leite, 500/202, RS CEP 90046-900, Porto Alegre, Brazil.
Toxicon. 2003 Jan;41(1):1-12. doi: 10.1016/s0041-0101(02)00241-6.
The calcinogenic plants are among the most noxious plants to animals in the world. The pathological and biochemical effects of calcinogenic plants in cattle, sheep, goats, pigs, horses, buffalo and laboratory animals have been determined. The chemical nature of the toxic agents and the precise mechanism by with the calcinogenic plants induces calcinosis have been defined. Most of the active principle present as steroidal glycoside is hydrolyzed in intestine, rumen and other tissues or by the bacterial flora releasing the steroidal fragment, in most cases 1,25(OH)(2)D(3). The excess of vitamin D stimulates CaBP synthesis and calcium and phosphate absorption, producing hypercalcemia and/or hyperphosphatemia. The excessively absorbed mineral cannot be physiologically accommodated, and the deposition in soft tissues results in calcinosis. The different means of treatment of calcinosis and control of calcinogenic plants are discussed with regards to their effectiveness. A number of potential uses of calcinogenic plants have been suggested but none has been exploited on a large scale. The understanding of the mechanisms involved with calcinosis contributed enormously to the compression of vitamin D mechanism. Research methods were developed and improved but a lot is to be done in this fascinating subject.
致钙化植物是世界上对动物毒性最强的植物之一。已确定致钙化植物对牛、羊、山羊、猪、马、水牛和实验动物的病理和生化影响。已明确了有毒物质的化学性质以及致钙化植物诱发钙质沉着症的确切机制。大多数以甾体糖苷形式存在的活性成分在肠道、瘤胃和其他组织中或被细菌菌群水解，释放出甾体片段，在大多数情况下是1,25(OH)(2)D(3)。过量的维生素D会刺激钙结合蛋白的合成以及钙和磷的吸收，导致高钙血症和/或高磷血症。过量吸收的矿物质无法在生理上得到调节，沉积在软组织中就会导致钙质沉着症。文中讨论了钙质沉着症的不同治疗方法以及致钙化植物的控制方法及其有效性。有人提出了致钙化植物的一些潜在用途，但尚未大规模开发利用。对钙质沉着症相关机制的理解极大地推动了对维生素D机制的研究。研究方法得到了发展和改进，但在这个引人入胜的领域仍有许多工作要做。
