Grases Felix, Tomàs Nadal Francisca, Julià Florit Francesca, Costa-Bauza Antonia
Laboratory of Renal Lithiasis Research, University Institute of Health Sciences Research (IUNICS-IdISBa), University of Balearic Islands, 07122 Palma de Mallorca, Spain.
J Clin Med. 2024 May 11;13(10):2837. doi: 10.3390/jcm13102837.
: Crystallization experiments of renal-calculi-forming compounds (calcium oxalate, calcium phosphates, uric acid) are normally performed by monitoring these processes during periods of time similar to the residence of urine inside the kidney. Nevertheless, cystine requires high supersaturation for its crystallization, and most experiments last for longer periods. It must be considered that at high supersaturation, the inhibitors of crystalline development have poor effects. : The induction time of crystallization (t) of cystine in experimental conditions similar to those of the formation of cystine renal calculi and the effect of different cystine-binding thiol agents was determined through turbidimetric measurements. We also studied the macro- and microstructure of 30 cystine kidney stones through stereoscopic microscopy and scanning electron microscopy. : Under the studied conditions, the t in absence of crystallization inhibitors was 15 min, and the presence of 9 mM of penicillamine, tiopronin, or N-acetylcysteine totally inhibited crystallization, as their effects relate to the formation of complexes with cystine, although N-acetylcysteine also delayed cystine crystalline development and modified cystine crystal morphology. Cystine stones have traditionally been classified as smooth and rough. The study of their structure shows that all of them begin their formation from a few crystals that generate a compact radial structure. Their subsequent growth, depending on the renal cavity where they are located, gives rise to the rough structure in the form of large blocks of cystine crystals or the smooth structure with small crystals. : To prevent the development of cystine renal stones, the formation of small crystals must be avoided by reducing urinary cystine supersaturation, with N-acetylcysteine being the most effective among the studied cystine-binding thiol agents. Also, the removal of cystine crystals through increased water intake and physical activity can be a very important preventive measure.
肾结石形成化合物（草酸钙、磷酸钙、尿酸）的结晶实验通常是通过在与尿液在肾脏内停留时间相似的时间段内监测这些过程来进行的。然而，胱氨酸结晶需要高过饱和度，并且大多数实验持续时间更长。必须考虑到，在高过饱和度下，晶体生长抑制剂的效果不佳。：通过比浊法测量确定了在与胱氨酸肾结石形成条件相似的实验条件下胱氨酸结晶的诱导时间（t）以及不同胱氨酸结合硫醇试剂的作用。我们还通过立体显微镜和扫描电子显微镜研究了30颗胱氨酸肾结石的宏观和微观结构。：在所研究的条件下，在没有结晶抑制剂的情况下t为15分钟，9 mM青霉胺、硫普罗宁或N - 乙酰半胱氨酸的存在完全抑制了结晶，因为它们的作用与与胱氨酸形成复合物有关，尽管N - 乙酰半胱氨酸也延迟了胱氨酸晶体生长并改变了胱氨酸晶体形态。传统上，胱氨酸结石分为光滑型和粗糙型。对其结构的研究表明，所有结石都从少数晶体开始形成，这些晶体形成紧密的放射状结构。它们随后的生长，取决于它们所在的肾腔，产生了大的胱氨酸晶体块形式的粗糙结构或小晶体形式的光滑结构。：为了防止胱氨酸肾结石的形成，必须通过降低尿液胱氨酸过饱和度来避免小晶体的形成，在研究的胱氨酸结合硫醇试剂中，N - 乙酰半胱氨酸是最有效的。此外，通过增加饮水量和体育活动来清除胱氨酸晶体可能是一项非常重要的预防措施。
