OBJECTIVETo explore the effects of tetrandrine on inhibition of capsular contracture in rabbits.

METHODS12 female New Zealand white rabbits were randomly divided into two groups with 6 animals in each group. Four smooth silicone implants (15 ml each) were implanted beneath the panniculus carnosus muscle of each rabbit. 20 mg tetrandrine was given in side of the implant cavity in the experimental group intraoperatively. All animals were sacrificed 3 months after operation. Capsular tensility, wet weight, collagen content and capsular histological examinations were carried out. In addition, The expression of alpha-smooth muscle actin (a-SMA) were examined by immunohistochemistry.

RESULTSCapsular tensility and capsular wet weight and capsular collagen content in the control group were significantly higher than that in the tetrandrine group (P < 0.01). alpha-SMA positive cell numbers in control group was obviously higher than that in the tetrandrine E group (P < 0.01). Capsular thickness were no statistical difference between 2 groups (P > 0.05). The capsular microstructure of control group was similar in two groups. The inner layer of capsule was smooth. The middle layer was lamellated fibrous tissue. The outer layer was loose connective tissue. Collagen fibres in control group was dense, the middle layer was thicker than that of the tetrandrine group. Typical myofibroblasts were found in both of 2 types of capsules. Myofibroblasts with swollen mitochondria and dilated rough and chromatin margination endoplasmic reticulum were found in the tetrandrine group.

CONCLUSIONSThis study verified the efficiency of tetrandrine in inhibiting the capsular contracture.