Effects of repeated administration of methylphenidate on reproductive parameters in male rats.

Methylphenidate (MPH) is a psychostimulant drug which acts by blocking the dopamine and norepinephrine transporters and is the main drug used to treat attention deficit hyperactivity disorder in children and adolescents. During puberty, changes in neurotransmitter systems (including dopaminergic system) are engaged on the release of gonadal hormones and the development of cephalic structures responsible for reproductive function. This study investigated the effects of repeated treatment with methylphenidate during development on reproductive parameters of adult male rats. Wistar rats received MPH 2.5 mg/kg, MPH 5.0 mg/kg, or distilled water (gavage) from postnatal day (PND) 21 to PND 60. At PND 100, an increase in percentage of abnormal tail morphology sperm in MPH 2.5 and increase in testicular interstitial tissue volume in MPH groups as well as in the number of type A spermatogonia in MPH 5.0 group were observed. This study demonstrated that repeated administration of methylphenidate during periods corresponding childhood to early adulthood interfered on testicular function in rats at adult life.

Lactational exposure to sulpiride: assessment of maternal care and reproductive and behavioral parameters of male rat pups.

Dopaminergic receptor antagonists may be used as galactagogues because they increase serum prolactin (PRL) by counteracting the inhibitory influence of dopamine on PRL secretion. The antipsychotic drug sulpiride (SUL) is documented to be effective as a galactagogue, but it is transferred through milk to the neonates. The aim of the present study was to evaluate if maternal exposure to SUL during lactation could disrupt maternal care and/or male offspring reproductive development. The dams were treated daily (gavage) with SUL 2.5mg/kg or 25mg/kg during lactation. Maternal behavior was analyzed on lactational days 5 and 10. In offspring, reproductive and behavioral parameters were analyzed at different time points. SUL treatment did not impair maternal care, but caused testicular damage in male offspring. At postnatal day 90, a reduction in testis weight, volume of seminiferous tubule and histopathological alterations such as an increased percentage of abnormal seminiferous tubules were observed. Data shows that maternal exposure to SUL during lactation may impact the reproductive development of male rats and the testes seem to be the main target organ at adulthood.