The psoralens adversely affect reproductive function in male wistar rats

The psoralens occur naturally in produce and are widely used in skin therap y. Studies show that 5-methoxypsoralen and 8-methoxypsoralen reduced birth rates in rats. We determined the effect of psoralens on reproductive functi on in male rats. Male Wistar rats were dosed daily with 5-methoxypsoralen o r 8-methoxypsoralen (75 or 150 mg/kg, p.o.), or vehicle control. Treated ma les had significantly smaller pituitary glands, fewer sperm per ejaculate, and fewer sperm in the vasa defferentia and epididymides than controls. Dos ing significantly elevated levels of testosterone and increased relative te stis weight, but did not directly affect testicular weight. Females bred to dosed males required more time to become pregnant, and these males require d more breeding attempts. The findings demonstrate the importance of determ ining the potential risk for infertility and/or birth defects in humans who are exposed to therapeutic, dietary, or occupational psoralens. (C) 2001 E lsevier Science Inc. All rights reserved.