Comparative anti-androgenic actions of vinclozolin and flutamide on transgenerational adult onset disease and spermatogenesis

Abstract

Exposure of gestating female rats to the anti-androgenic endocrine disruptor vinclozolin has been shown to induce transgenerational adult onset disease phenotypes. The current study, was designed to compare the actions of vinclozolin to the known anti-androgenic compound flutamide. The gestating female rats were exposed to intraperitoneal injections during embryonic day 8-14 (E8-E14) to 100mg/kg/day vinclozolin or flutamide at either 5mg or 20mg/kg/day. As previously observed, vinclozolin induced a transgenerational testis phenotype of increased spermatogenic cell apoptosis and decreased epididymal sperm number. In contrast, the flutamide exposures resulted in a testis phenotype of increased spermatogenic cell apoptosis and decreased epididymal sperm numbers in the F1 generation only, and not the F2 and F3 generation adult males. Interestingly, some of the low dose (5mg/kg) flutamide F2 generation offspring developed spinal agenesis and supernummery development (polymelia) of limbs. Although the actions of vinclozolin and flutamide appear similar in the F1 generation males, the transgenerational effects of vinclozolin do not appear to be acting through the same anti-androgenic mechanism as flutamide.

Fig. 1

Spermatogenic cell apoptosis (TUNEL) analyses of 100-day-old F3 generation testis cross-sections from control (A and C) vinclozolin (B) and flutamide 20 mg/kg/day dose (D) 400× magnification. (A) Tunel F3 control; (B) Tunel F3 vinclozolin; (C) Tunel F3 control; (D) Tunel F3 flutamide 20mg dose. Arrows indicate apoptotic cells.

Fig. 2

Spermatogenic cell apoptosis in P60–150 control and vinclozolin (A) and flutamide (B) rats in the F1, F2, and F3 generations. Statistically significant differences between control and treated generations are indicated by (*) for p < 0.05.

Fig. 3

Caudal epididymal sperm motility in P60–P150 control and vinclozolin (A) and flutamide (B) rats in the F1, F2, and F3 generations. Statistically significant differences between control and treated generations are indicated by (*) for p < 0.05. The n value for each bar ranged between 10 and 25 animals.

Fig. 4

Caudal epididymal sperm concentrations in P60–P150 control and vinclozolin (A) and flutamide (B) rats in the F1, F2, and F3 generations. Statistically significant differences between control and treated generations are indicated by (*) for p < 0.05. The n value for each bar ranged between 10 and 25 animals.

Fig. 5

Morphogenic analysis (X-ray imaging) of F2 flutamide generation T5 animals with skeletal abnormalities. Control animal (A) supernummery development (polymelia) of limbs (B), spinal agenesis of lumbar vertebrae, tail vertebrae, pelvis (C and D). Red circles denote area of spinal agenesis and white arrows identify additional limbs. Both male and female sexes represented. Phenotype observed in (5/128) animals represented in three out of four lines from two separate experiments.