Manipulation of pre and postnatal androgen environments and anogenital distance in rats.

We examined the anogenital distance (AGD) plasticity in rats through the manipulation of the androgen environment in utero and during puberty. Dams were treated from gestation days 13-20 with vehicle, flutamide (20mg/kg/day), di-(2-ethylhexyl) phthalate (DEHP, 750mg/kg/day), or testosterone (1.0mg/kg/day). After weaning, male pups were randomly assigned to one of four postnatal groups, which received the same treatments given prenatally. Sixteen treatment groups were established based on the combination of pre- and postnatal exposures. The postnatal treatments were conducted from postnatal days 23-53. In utero flutamide and DEHP exposure significantly shortened male AGD, although this effect was more pronounced in flutamide-exposed rats. Postnatal flutamide, DEHP, and testosterone induced slight but significant reductions in male AGD. Our study indicates that AGD is a stable anatomical landmark that reflects the androgen action in utero, although it can also be slightly responsive to changes in the androgen environment following pubertal exposure.

Impairment on sperm quality and fertility of adult rats after antiandrogen exposure during prepuberty.

This study evaluated the effects of antiandrogen exposure during the prepubertal period on reproductive development and reproductive competence in adults. Male rats were divided into two groups: flutamide, receiving 25 mg/kg/day of flutamide by oral gavage and control, receiving vehicle daily. Dosing continued from PND 21 to 44, and animals were killed on PND 50 or PND 75-80. The epididymis, prostate, vas deferens and seminal vesicle weights were lower in Flutamide group on PND 50, while on PND 80 only seminal vesicle weight was reduced. Fertility assessed by IUI revealed a decrease in the fertility potential in the flutamide-treated adults. Flutamide accelerated sperm transit time through the epididymis, impairing sperm motility and storage. A quantitative analysis of the cauda sperm membrane proteome revealed a few significant changes in protein expression. Thus, exposure to flutamide during the prepubertal period compromises the function of the epididymis along with epididymal sperm quality at adulthood.

Copulatory efficiency and fertility in male rats exposed perinatally to flutamide.

This study investigated the effects of perinatal treatment with flutamide on male sexual behavior, semen parameters, and fertility in adult male rats. Pregnant rats received 15 mg/kg of flutamide or peanut oil, s.c., at days 19 and 22 of pregnancy and for the first five postnatal days. Treated male offspring showed increases in latency to copulatory behavior, number of mounts without penis intromission, number of intromissions until ejaculation, latency to ejaculation, and reduced number of ejaculations. Flutamide treated rats presented reductions in weight of testes and prostate, percentage of normal spermatozoa, spermatozoa concentration, testicular sperm production, and testosterone level. Normal females mated with treated males presented more pre-implantation losses, reduced implantation rates, and consequently reduced offspring size. The results indicated that perinatal flutamide treatment damaged organizational processes of sexual differentiation, which led to inefficiency in copulatory behavior and reductions in sperm quality and count, resulting in low capacity for producing descendants.

Increase in apoptosis and of the stress protein HSP70 in the mouse epididymis produced by the antiandrogen flutamide / El antiandrógeno flutamida produce un aumento de la apoptosis y de la proteína de stress HSP70 en el epidídimo del ratón

The general aim of this paper was to characterize some changes induced by androgen receptors blockage in the epithelial cells of the mouse epididymis. The antiandrogen flutamide was injected (10 mg/Kg b.w.) to adult male mice which were sacrificed 24h. and 72h. after. Controls injected with the vehicle (corn oil) were sacrificed at the same intervals. Cryosections were made of the epididymides and examined by the TUNEL method for quantification of apoptosis and also using immunocytochemistry to visualize the expression of the stress protein HSP70. The highest indexes of apoptosis were observed in the caput epididymis after 72 h. and were of 7.40 cells/1000 in contrast to controls (0.21 cells/1000). HSP70 appeared particularly increased in the caput and cauda epididymis after 72 h. treatment. Results indicated that the blockage of androgen receptors induces apoptosis and a HSP70 expression in the principal epithelial cells of the mouse epididymis, and that these changes occur in a region-specific fashion.

Este trabajo estudia los cambios inducidos por el bloqueador de receptores de andrógeno flutamida en el epitelio del epidídimo del ratón. Varios machos adultos fueron inyectados con flutamida (1Omg/Kg.b.w.) y se sacrificaron a las 24 y 72horas. Otros machos, que sirvieron de controles fueron inyectados sólo con el vehículo empleado para las inyecciones (aceite de maíz) y se sacrificaron a intervalos similares. Los epidídimos tratados y controles fueron examinados mediante el método TÚNEL para cuantificar la apoptosis y mediante procedimientos inmunocitoquímicos para localizar la proteína de stress HSP70. El índice apoptótico más alto fue observado en la cabeza del epidídimo después de 72 horas de tratamiento. HSP70 se observó también a las 72 horas en la cabeza y en la cauda epididimaria. Los resultados indican que el bloqueo de los receptores de andrógenos induce apoptosis y expresión de HSP70 en las células principales del epitelio epididimario, y que estos cambios ocurren afectando a regiones específicas del epidídimo.

Photochemistry and phototoxicity studies of flutamide, a phototoxic anti-cancer drug.

The phototoxic anti-cancer drug flutamide is photolabile under UV-B light in either aerobic or anaerobic conditions. Irradiation of a methanol solution of this drug produces several photoproducts, one by photoreduction of the nitro group, one by rupture of the aromatic-NO2 bond of the parent compound, two as a result of the rupture of the CO-NH bond and one derived from the photoreduction product by scission of the aromatic-NH2 bond. Flutamide shows a photohemolytic effect on human erythrocytes and photoinduces lipid peroxidation. Studies on peripheral blood polymorphonuclear cells (neutrophils) demonstrated the phototoxicity of flutamide as well as inhibition of the cytotoxicity respiratory burst by the photoproduct derived from its photoreduction. The results suggest that the inhibition of the respiratory burst observed in phorbol myristate acetate (PMA)-activated cells is mediated by photosensitization and concomitant singlet oxygen production and/or formation of toxic photoproducts.