Statin exposure during pregnancy promotes neuromuscular junction alterations in postpartum Wistar rats.

INTRODUCTION/AIMS: The mechanisms that underlie the pathogenesis of statin-associated muscle symptoms (SAMS) remain unclear. Pregnancy is associated with increased cholesterol levels. Statins may be useful during pregnancy, but their safety is uncertain. Hence, we investigated the postpartum effects of exposure to rosuvastatin and simvastatin during pregnancy in Wistar rats, targeting the neuromuscular structures. METHODS: Twenty-one pregnant Wistar rats were divided into three groups: control (C) treated with vehicle (dimethylsulfoxide + dH20), simvastatin (S) 62.5 mg/kg/day, and rosuvastatin (R) 10 mg/kg/day. Gavage was performed daily from the gestational days 8 to 20. At weaning, the postpartum mother tissues were collected and subjected to morphological and morphometric analysis of the soleus muscle, associated neuromuscular junctions (NMJs), and the sciatic nerve; protein quantification; quantification of the cholesterol and creatine kinase in the serum; and intramuscular collagen analysis. RESULTS: An increase in morphometric parameters (area, maximum and minimum diameters, Feret diameter, and minimum Feret) was observed in NMJs from the S and R groups in comparison with the C group, and there was also a loss of common NMJ circularity. The number of myofibers with central nuclei was higher in S (17 ± 3.9, P = .0083) and R (18.86 ± 14.42, P = .0498) than in C (6.8 ± 2.6). DISCUSSION: Gestational exposure to statins induced postpartum NMJ morphology alterations in soleus muscle, which may be caused by the remodeling of clusters of nicotinic acetylcholine receptors. This may be associated with the development and progression of SAMS observed in clinical practice.

Reproductive outcomes of neonatal exposure to betamethasone in male and female rats.

Betamethasone (BM) is the drug of choice for antenatal corticosteroid therapy for women at risk of preterm delivery because it induces fetal lung maturation and enhances survival after birth. However, our group reported evidence of fetal programming and impaired reproductive development and function in rats exposed during the critical window of genital system development. Therefore, we aimed to investigate the effects of BM on the sexual development of rats in the period that corresponds to antenatal corticosteroid therapy in humans. Male and female rats were exposed subcutaneously to BM at 0.1 µg/g of pups' body weight or to a NaCl 0.9% solution (control) on postnatal days 1-3. It was observed that neonatal exposure to BM decreased body weight and weight gain in male and female rats during treatment. The estrous cycle was deregulated and LH level was decreased in female rats. In male rats, the sperm concentration in the caput-corpus of the epididymis was decreased, whereas the sperm transit time and sperm concentration in the cauda of the epididymis were increased. Our results demonstrated that neonatal exposure to BM impaired body growth of male and female rats, deregulated the estrous cycle of female rats, and altered sperm quality of male rats. Therefore, BM exposure from postnatal days 1 to 3 corroborated results previously observed after prenatal exposure to this drug. Despite the recognized importance of human antenatal corticosteroid therapy, the findings of this study should encourage further studies in order to minimize possible adverse postnatal effects.

Rosuvastatin exposure in female Wistar rats alters uterine contractility and do not show evident (anti)estrogenic effects.

Statins are 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibitor drugs that lead to serum-cholesterol-lowering effects. Rosuvastatin, a third-generation statin, has shown better results in reducing cholesterol concentrations when compared to other widely prescribed statins. Recent studies by our group reported that rosuvastatin impairs reproductive function in rats possibly by disrupting the reproductive-endocrine axis. In this study, we evaluated whether rosuvastatin presents estrogenic or antiestrogenic effects, by an in vivo uterotrophic assay in rats, and investigated the direct effect of this drug upon rat uterine tissue contractility both in non-gravid and gravid periods. Rosuvastatin exposure in vivo at doses of 0 (control), 3, and 10 mg/kg/d was not associated with estrogenic or antiestrogenic effects on uterine tissue. However, in vivo (doses of 0, 3, and 10 mg/kg/d) and ex vivo (concentrations of 0, 1, 10, and 100 µg/mL) exposures to this drug were related to alterations in uterine basal contraction pattern. Furthermore, in vivo and ex vivo rosuvastatin exposures potentially modulate the action of uterine contraction inducers carbachol, norepinephrine, and prostaglandin E2. Thus, rosuvastatin can affect uterine physiology not necessarily by an endocrine mechanism related to the estrogen signaling, but possibly by its pleiotropic effects, with indirect tissue and cellular interactions, since in vivo and ex vivo exposures of uterine fragments to rosuvastatin presented different responses in uterine contractile parameters, which require further studies upon the precise mechanism of action of this drug in female reproductive function.

Ascorbic acid supplementation ameliorates testicular hormonal signaling, sperm production and oxidative stress in male rats exposed to rosuvastatin during pre-puberty.

Dyslipidemias are occurring earlier in the population due to the augmentation of obesity. Rosuvastatin reduces cholesterol and triglycerides; however, previous studies have shown that it may affect male reproduction. Ascorbic acid (AA), an antioxidant compound, plays a protective role in the male reproductive system. This study aimed to evaluate whether pre-pubertal exposure to rosuvastatin may impair testicular structure and antioxidant status in male rats and if supplementation with AA may alleviate these damages. Male rats were randomly divided into six experimental groups (n = 10) on postnatal day (PND) 23 and received the different treatments by gavage from PND 23 to 53. The experimental groups received vehicle (saline solution 0.9%), 3 or 10 mg/kg/day of rosuvastatin diluted in saline solution 0.9%, supplementation with 150 mg/day of AA, 3 mg/kg/day of rosuvastatin in association with 150 mg/day of AA or 10 mg/kg/day of rosuvastatin associated with 150 mg/day of AA. Testicular parameters were assessed on PND 53 and 110. There were diminished androgen receptors staining in the Sertoli cells and increased germ cell death in rosuvastatin-exposed groups, in both periods. Spermatids showed lower estrogen alpha-receptors staining in the group exposed to 10 mg of statin at adulthood. There were androgen depletion and increased lipid peroxidation and catalase activity in statin-exposed groups. Rosuvastatin exposure during pre-puberty impaired testicular structure, steroid receptor distribution and increased oxidative stress; however, AA was able to ameliorate the impairment provoked by statin exposure.

Impact of intrauterine exposure to betamethasone on the testes and epididymides of prepubertal rats.

Therapy with betamethasone, a synthetic glucocorticoid, is used in cases of preterm birth risk, in order to promote fetal lung maturation, and decrease neonatal mortality and morbidity. However, late reproductive disorders related to the prenatal exposure to this compound have been reported by our Laboratory, in both male and female rats. Thus, the present study aimed to evaluate the impact of betamethasone on postnatal reproductive development, during pre-puberty, of male offspring exposed in utero to this synthetic glucocorticoid. For this purpose, pregnant Wistar rats were allocated into two groups: Control, treated with saline, and the group treated with betamethasone at 0.1 mg/kg/day. Control and betamethasone groups were treated with intramuscular injection on gestational days 12, 13, 18 and 19, critical days of prenatal reproductive development. The treatment is associated with reduced body and organ weights, disorders in initial reproductive parameters of pre-pubertal male offspring exposed in utero to betamethasone, such as reduction of anogenital distance, alterations in histomorphometric parameters and immunostaining pattern of androgen and estrogen receptors on testicles and epididymides. Our results suggest that prenatal exposure to betamethasone potentially causes reproductive reprogramming and impairs male postnatal reproductive development. This data raise concerns about the use of betamethasone for human antenatal therapy.