Reproductive parameters of female Wistar rats treated with methylphenidate during development

Postnatal undernutrition increases estradiol plasma levels and sexual receptivity and disrupts the kisspeptin-GnRH pathway in adult female rats

Undernutrition has increased worldwide in recent years and it is known that environmental factors to which individuals are exposed in early life can result in metabolic and reproductive changes that remain in adult life. In this context, the litter size expansion is a classic model used to induce undernutrition early in development. Thus, this study aimed to evaluate the effects of neonatal undernutrition induced by the litter size expansion on metabolic and reproductive parameters of female rats. At birth, litter size was adjusted to large (LL - 16 pups) and normal (NL - 10 pups) litters. After weaning, the feed was offered ad libitum and the animals were euthanized from postnatal day 90, when in proestrus. Neonatal undernutrition resulted in lower body weight from weaning to adulthood, although food intake remained higher in the LL group in this period. These animals exhibited a delayed onset of puberty, demonstrated by a late first estrus, increased values of circulating estradiol, luteinizing hormone, follicle-stimulating hormone, and number of antral follicles in the ovaries, associated with higher sexual receptivity, without differences in maternal behavior. The LL group also exhibited decreased messenger RNA (mRNA) expression of kisspeptin and gonadotropin-releasing hormone (GnRH) in the preoptic area, without changes in the mRNA expression of GnRH receptor in the pituitary. These results demonstrate that moderate undernutrition in the lactational period promotes metabolic changes associated with impairments in the kisspeptin-GnRH pathway, without compromising maternal behavior and peripheral reproductive functions such as estrous cyclicity, sexual receptivity, and fertility.

ADHD and Risk of Precocious Puberty: Considering the Impact of MPH

BACKGROUND/OBJECTIVES

The complex association between attention-deficit/hyperactivity disorder (ADHD) and methylphenidate (MPH) with precocious puberty (PP) is still unclear. This study aims to investigate the association between ADHD, MPH, and PP.

METHODS

This is a nationwide cohort study including a total of 3,342,077 individuals, 186,681 with ADHD and 3,155,396 without. First, we compared the risk of PP between ADHD cases and non-ADHD cases. Second, we compared the risk of PP between MPH users and non-MPH users in patients with ADHD.

RESULTS

Patients with ADHD were at a greater risk of PP (adjusted hazard ratio [aHR], 2.01 [95% CI, 1.91-2.11]). In our moderation analyses, the female gender was a positive additive effect modifier of the association between ADHD and PP, whereas tics and intellectual disability were negative effect modifiers. In patients with ADHD, MPH users had a significantly lower risk of PP (aHR, 0.63 [95% CI 0.57-0.70]), and females had a negative effect modification on the association between MPH and PP.

CONCLUSIONS

Our study found that children with ADHD were at a greater risk of PP. Girls with ADHD were a group particularly vulnerable to PP. Comorbid tics or intellectual disability was associated with a lower risk of PP. Among patients with ADHD, MPH was protective against PP, especially in girls. However, these preliminary results need further validation due to the nature of them being from an electronic database study. Unmeasured confounding factors might affect the association between MPH and PP.

Insights from the maternal lineage of the F2 generation after exposure to an environmentally relevant dose of benzo(a)pyrene in the male rats of F0 generation

Benzo(a)pyrene (BaP) is a substance with the potential to induce endocrine disruption in the F0 generation and cause adverse multigenerational effects (F1 generation) for reproductive parameters in rats. The objective of this study was to investigate the occurrence of transgenerational inheritance in the reproductive aspects of male and female rats belonging to the F2 generation (MF2). This investigation was conducted following the exposure of male rats from the F0 generation to BaP to assess potential effects on subsequent generation from the maternal lineage (F1). For that, juvenile male Wistar rats (F0) were orally exposed to BaP (0.1 µg/kg/day) for 31 consecutive days. In adulthood, they were mated with untreated females to obtain female offspring (F1), which later produced the MF2. In the MF2 generation, both males and females exhibited increased body weight on postnatal day (PND) 1. In MF2 males, we observed delayed preputial separation, altered pup weight, reduced levels of follicle-stimulating hormone (FSH), increased intratesticular testosterone levels, decreased type A sperm, epididymal disturbances, reduced 5 α-reductase activity, increased testicular proliferation, and alterations in testicular antioxidant enzymes. In MF2 females, we noted morphological uterine enlargement, reduced sexual activity, and decreased progesterone levels. The findings suggest that the alterations observed in both MF2 males and females can be attributed to modifications in the sperm from F0 generation, which were subsequently transmitted to F1 females and MF2 generation due to BaP exposure.

Paternal low-dose benzo(a)pyrene exposure in rats impairs sexual development and fertility of the paternal lineage in F2 generation: A transgenerational study

The field of Paternal Origins of Health and Disease (POHaD) is highly relevant but remains under-explored. The F2 generation from males indirectly exposed (F1 - via germ cells) to benzo(a)pyrene (BaP), named PF2, was investigated in this study under parameters of sexual development and reproductive performance of male and female rats. Male Wistar rats (F0) were exposed to BaP (0.1µg/kg/day) for 31 consecutive days (gavage) during prepuberty. The F0 rats were mated with untreated females to produce male offspring (F1), which were exposed to BaP via germ cells. The F1 males were later mated with untreated females to obtain the PF2 generation, which was the focus of our investigation. Our findings showed that PF2 males exhibited a decrease in anogenital distance, fertility potential, testosterone levels, and type A sperm. Meanwhile, PF2 females had an earlier vaginal opening, lower lordosis scores, and decreased fertility. Furthermore, changes in the histomorphology of the testis/epididymis and ovary/uterus were observed. The repercussions of the PF2 generation indicate that these animals showed losses in both sexual development and fertility potential, and we can conclude that this damage remained due to paternal transgenerational inheritance caused by a low dose of BaP.

Effect of Methylphenidate on the onset of puberty and reproductive organ development in rats

Methylphenidate (MPH) is the first-line therapy for attention deficit hyperactivity disorder (ADHD) in children and adolescents. The aim of this study was to investigate the effects chronic MPH administration on reproductive parameters in both male and female pre-pubertal rats and reversibility of these effects. Sprague-Dawley rats were administered with 5 mg/kg MPH or saline orally from postnatal day (PND) 21 to PND60 and from PND21 to PND90. In addition, recovery groups from both sexes, in which MPH administration was stopped from PND60 to PND90 were included. Puberty onset, serum luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and estradiol levels were determined. Histopathology of male and female reproductive organs was examined. Puberty onset was significantly early in the males (p<0.01), but late in females (p<0.05). In males, serum LH and FSH levels were similar. Testosterone levels tended to decrease in MPH-treated animals. Morphology of testes, epididymis and vas deferens was disrupted in MPH-treated animals, while it was improved in the recovery group. In females, estradiol levels decreased in MPH-treated group compared to controls, and elevated LH levels were detected in recovery group. Similar to the males, disruption in the reproductive organ histology was seen with morphological deterioration in basement membrane of the ovaries of MPH-treated groups. These adverse effects of MPH were recovered after drug cessation for 30 days. The present results demonstrate that MPH could affect the reproductive functions in both male and female rats. However, our findings also suggest that those effects are transient.

Sulfasalazine exposure during pregnancy and lactation induces alterations in reproductive behavior in adult female rat offspring

AIMS

Sulfasalazine (SAS) is the first line drug in the treatment of chronic inflammatory bowel diseases in pregnant women. SAS and its metabolites cross the placenta and can be transferred through the milk. However, the long-term consequences to the reproductive system of offspring from dams exposed to SAS have not yet been studied. Thus, our study investigated the effects of SAS treatment during gestational and lactational periods on maternal care in F0 and reproductive outcomes in F1 females.

MAIN METHODS

Wistar female rats (n = 10/group) received 300 mg/kg/day of SAS dissolved in carboxymethyl cellulose (CMC), by gavage, from gestational day 0 to lactation day 21 and 3 mg/kg/day of folic acid during gestation. The control group received CMC only. On PND 21, the female pups were selected for reproductive evaluation at different time points: infancy and adulthood. The reproductive parameters evaluated were installation of puberty (vaginal opening and first estrus), estrous cyclicity, reproductive organs weight, histological analysis of the ovary follicles and uterus, analysis of oxidative stress in ovarian tissue, reproductive behavior (sexual and maternal), and fertility.

KEY FINDINGS

SAS treatment decreased the retrieving behavior in F0 females. The F1 females presented an increase in the lordosis score, frequency of lordosis of magnitude 3, and lipid peroxidation of ovarian tissues in both infancy and adult life.

SIGNIFICANCE

The SAS effects observed in the current study represent a relevant concern for public health, as they demonstrated that treatment with SAS compromised the maternal motivation of dams and induced reproductive alterations in F1 females.

Potential disturbance of methylphenidate of gonadal hormones or pubescent development in patients with attention-deficit/hyperactivity disorder: A twelve-month follow-up study

Several animal or case reports have demonstrated that methylphenidate (MPH) disrupts endogenous gonadal hormones and interferes with the pubescent development of children with attention-deficit/hyperactivity disorder (ADHD). Therefore, this prospective study examined the changes in gonadal hormones and pubescent development in children with ADHD undergoing 12-month MPH treatment. We recruited 146 patients with ADHD (mean age: 8.9 years, 76.7% males) and 70 healthy controls (mean age: 9.2 years, 65.7% males). Blood samples were obtained to measure the serum levels of sex hormone-binding globulin (SHBG), follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, testosterone, free testosterone, and prolactin in each child. The sex maturation of ADHD patients was evaluated using the Tanner Stage. Patients with ADHD (107 received MPH treatment and 39 were under natural observation) were followed up for 12 months, and we re-examined hormone levels and Tanner Stage at the endpoint. During a 12-month follow-up for all ADHD patients, the serum levels of SHBG and progesterone significantly decreased, while LH, FSH, and free-testosterone levels significantly increased. However, the duration, drug formulations, and doses of the MPH treatment did not significantly influence gonadal hormone trends or changes of Tanner Stage. This study provides evidence about gonadal hormone trends and pubescent development in children with ADHD who receive long-term MPH treatment in natural settings. We suggest that MPH treatment at usual doses does not significantly alter gonadal function trends in ADHD patients over the course of one year.

Effect of paracetamol treatment on maternal care and reproductive outcomes in female rat offspring

Paracetamol (PAR) is one of the most commonly used drugs by pregnant women because it is considered safe for the mother and fetus. However, PAR is transferred into breast milk and crosses the blood-placental barrier, being present in the progeny during important stages of development. Intrauterine exposure to PAR may decrease the anogenital distance and follicle reserve in female rodent offspring. Therefore, the aim of the present study was to evaluate whether maternal PAR treatment altered the reproductive behaviour of dams and the sexual development of female rat offspring. Pregnant Wistar rats were gavaged daily with 350mg kg-1 day-1 PAR or water during gestation (from Gestation Day (GD) 6 until delivery) or during gestation and lactation (from GD6 until weaning). Maternal PAR treatment had maternal effects (increased grooming behaviour), and resulted in impaired sexual behaviour, decreased follicle reserve and increased plasma oestradiol concentrations in female offspring.

Impaired reproduction after exposure to ADHD drugs: Systematic review of animal studies

BACKGROUND:

Few studies have reported on long-term harms caused by ADHD drugs but they are known to impair growth.

OBJECTIVE:

To assess whether ADHD drugs impair reproduction in mammals.

METHODS:

Systematic review of reproduction in studies of animals treated with ADHD drugs.

DATA SOURCES:

PubMed, Biosis and EMBASE.

RESULTS:

We included 17 studies. The studies were generally of poor quality or poorly reported. Two studies reported the use of one of three advised randomisation methods. Fifteen studies used placebo which suggested blinding. On clonidine, the ability to produce offspring was reduced for male rats, which approached two females each. In one study, 10 treated rats produced no offspring while all four controls did. In another study, 10 treated rats impregnated nine females while 10 controls impregnated 16. On methylphenidate, vaginal opening was delayed in two studies (in one, the mean difference was 4.0 days, 95% CI 2.5 to 5.6, and number of estrous cycles was halved; in the other, the minimum delay was 6 days), while in two other studies no difference occurred. Generally, the impairments improved after a drug-free period and were less pronounced when treatment started later in life.

CONCLUSION:

ADHD drugs impair the reproduction in animals.