In vitro dissolution of calcium oxalate stones with ethylenediaminetetraacetic acid and snake venom thrombin-like enzyme.
OBJECTIVE
The aim of this study was to determine the feasibility of using snake venom thrombin-like enzyme (SVTLE) and/or ethylenediaminetetraacetic acid (EDTA) to dissolve calcium oxalate stones in vitro.


METHODS
Seven calcium oxalate stones were incubated with various chemolytic agents [EDTA, Tris-HCl/EDTA (TE) buffer or SVTLE diluted in TE buffer]. The pH, calcium concentration, stone weight and stone surface integrity were recorded, as well as related pathological changes to bladder mucosae.


RESULTS
Compared to all other solutions, those containing SVTLE and buffered EDTA had higher concentrations of mobilized calcium and caused significantly more stone weight loss, stone fragility and gaps in the calcium crystals. Also, there were no adverse pathological effects on rabbit bladder mucosae from any of the solutions.


CONCLUSIONS
The data indicate that buffered EDTA and SVTLE can be used to dissolve calcium oxalate stones and, at the concentrations used here, do not damage tissue.
Department of Urology, Renmin Hospital of Wuhan University, Wuhan, PR China.
Xiang-Jun
XJ
Zhou
Jie
J
Zhang
Ci
C
Zhang
Chang-Geng
CG
Xu
D000818:Animals; D002021:Buffers; D002129:Calcium Oxalate / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology* / Q000633:toxicity; D004492:Edetic Acid / Q000494:pharmacology* / Q000633:toxicity; D005240:Feasibility Studies; D006801:Humans; D066298:In Vitro Techniques; D009092:Mucous Membrane / Q000187:drug effects / Q000473:pathology; D011817:Rabbits; D012910:Snake Venoms / Q000201:enzymology*; D012995:Solubility; D013917:Thrombin / Q000302:isolation & purification / Q000494:pharmacology*; D001743:Urinary Bladder / Q000187:drug effects / Q000473:pathology; D014545:Urinary Calculi / Q000378:metabolism*
D002021:Buffers; D002614:Chelating Agents; D012910:Snake Venoms; D002129:Calcium Oxalate; D004492:Edetic Acid; D013917:Thrombin