APPLICATION OF THIAMINE IN PREVENTING MALFORMATIONS, SPECIFICALLY CLEFT ALVEOLUS AND PALATE, DURING THE INTRAUTERINE DEVELOPMENT OF RATS

Objective: Animal experiments were conducted to test the reproducibili ty of previously documented antiteratogenic effects of thiamine on cle ft formation in the craniofacial system. Design:Thirteen gravid Wistar rats carrying 98 fetuses were given the hydrazine derivative procarba cine (200 mg/kg BW) on the fourteenth day postconception (PC) to induc e malformations, chiefly cleft alveolus and palate (day of determining presence of sperm was called the first day PC), Seven of the treated gravid rats carrying 48 fetuses were additionally given a daily dose o f 200 mg/kg thiamine from the thirteenth to the nineteenth day PC. Out come Measures: A comparative analysis of the fetuses in both experimen tal groups was conducted externally and, for the skeleton, macroscopic ally using special staining techniques; the heads were analyzed using successional histologic sections; bodies were examined stereomicroscop ically using the razor-blade sectioning technique. Results: In 12 of t he 16 parameters evaluated, no statistically significant differences w ere found between experimental groups, In some cases, we even observed an amplifying effect of thiamine on the development of malformations in the rat strain used in our study. Conclusions: Because several prev ious authors have repeatedly described treatment with thiamine as one of the sufficient prophylactic measures in slowing the development of viscerocranial malformations, especially cleft alveolus and palate, it is of utmost importance that the timing of treatment and dosage of th iamine be taken into consideration not only in animal experiments but also when applying results to humans.