RESUMO
OBJECTIVE: To determine whether botulinum toxin type A (BTX-A) exerts a lipolytic effect by interfering with acetylcholine transmission at the cholinergic parasympathetic nerve endings. STUDY DESIGN: Fifteen male rabbits were divided into 3 equal groups: 1 control group (A) and 2 case groups (B and C). The abdomens of all rabbits were divided into a 3 x 3-square grid. The groups received 9 subcutaneous injections of 0.9% normal saline, 1 U BTX-A (group B) and 2 U BTX-A (group C), respectively. Four weeks later the entire grid was excised from the abdominal area. Hematoxylin-eosin-stained tissue was used for stereologic analysis to estimate cell surface and volume in 100 randomly selected cells. RESULTS: Gross thinning of subcutaneous fat and shattering and disappearance of fat globules were seen in both case groups. Fat cell volume was reduced by 65% in group B (p = 0.009) and 77% in group C (p = 0.009) compared to control animals. Fat cell surface also decreased by 51% in group B (p = 0.009) and 63% in group C rabbits (p = 0.009) compared to control animals. CONCLUSION: Our pilot animal study revealed a dose-dependent lipolytic effect of subcutaneous BTX-A injection.
