Alteration of catecholamine concentrations in rat testis after methamphetamine exposure

The gut microbiota contributes to methamphetamine-induced reproductive toxicity in male mice

Methamphetamine (METH) is a psychostimulant drug belonging to the amphetamine-type stimulant class, known to exert male reproductive toxicity. Recent studies suggest that METH can disrupt the gut microbiota. Furthermore, the gut-testis axis concept has gained attention due to the potential link between gut microbiome dysfunction and reproductive health. Nonetheless, the role of the gut microbiota in mediating the impact of METH on male reproductive toxicity remains unclear. In this study, we employed a mouse model exposed to escalating doses of METH to assess sperm quality, testicular pathology, and reproductive hormone levels. The fecal microbiota transplantation method was employed to investigate the effect of gut microbiota on male reproductive toxicity. Transcriptomic, metabolomic, and microbiological analyses were conducted to explore the damage mechanism to the male reproductive system caused by METH. We found that METH exposure led to hormonal disorders, decreased sperm quality, and changes in the gut microbiota and testicular metabolome in mice. Testicular RNA sequencing revealed enrichment of several Gene Ontology terms associated with reproductive processes, as well as PI3K-Akt signaling pathways. FMT conveyed similar reproductive damage from METH-treated mice to healthy recipient mice. The aforementioned findings suggest that the gut microbiota plays a substantial role in facilitating the reproductive toxicity caused by METH, thereby highlighting a prospective avenue for therapeutic intervention in the context of METH-induced infertility.

Can exposure to lisdexamfetamine dimesylate from juvenile period to peripubertal compromise male reproductive parameters in adult rats?

Lisdexamfetamine (LDX) is a d-amphetamine prodrug used to treat attention deficit and hyperactivity disorder, a common neurodevelopmental disorder in children and adolescents. Due to its action mediated by elevated levels of catecholamines, mainly dopamine and noradrenaline, which influence hormonal regulation and directly affect the gonads, this drug may potentially disrupt reproductive performance. This study evaluated the effects of exposure to LDX from the juvenile to peripubertal period (critical stages of development) on systemic and reproductive toxicity parameters in male rats. Male Wistar rats (23 days old) were treated with 0; 5.2; 8.6 or 12.1 mg/kg/day of LDX from post-natal day (PND) 23 to 53, by gavage. LDX treatment led to reduced daily food and water consumption, as well as a decrease in social behaviors. The day of preputial separation remained unaltered, although the treated animals exhibited reduced weight. At PND 54, the treated animals presented signs of systemic toxicity, evidenced by a reduction in body weight gain, increase in the relative weight of the liver, spleen, and seminal gland, reduction in erythrocyte and leukocyte counts, reduced total protein levels, and disruptions in oxidative parameters. In adulthood, there was an increase in immobile sperm, reduced sperm count, morphometric changes in the testis, and altered oxidative parameters, without compromising male sexual behavior and fertility. These findings showed that LDX-treatment during the juvenile and peripubertal periods induced immediate systemic toxicity and adversely influenced reproductive function in adult life, indicating that caution is necessary when prescribing this drug during the peripubertal phase.

Reduced Glycolysis Contributed to Inhibition of Testis Spermatogenesis in Rats After Chronic Methamphetamine Exposure

BACKGROUND Previous reports suggested that methamphetamine (METH) exposure could lead to inhibition of rat testis spermatogenesis. Glycolysis and glucose metabolism as well as oxidative stress have been implicated in testis spermatogenesis. Here we explored the underlying mechanism of local metabolism and glycolysis of testis after METH exposure. MATERIAL AND METHODS METH was intraperitoneally injected into rats with different doses and duration of METH exposure to establish short-term and chronic exposure models. The serum 8-hydroxy-2 deoxyguanosine (8-OHdG) level of rats was detected by enzyme-linked immunosorbent assay. Untargeted gas chromatography-mass spectrometry analysis was applied to identify differential metabolites and metabolic signature. The mRNA expression of hypoxia inducible factor 1alpha (HIF1alpha), glucose transporter 1 (GLUT1), hexokinase 1 (HK1) and lactate dehydrogenase C (LDHC) in rat testes were detected by polymerase chain reaction. Further, we determined the 4 proteins with western blotting and immunohistochemistry. RESULTS Decreased testes index and sperm counts were showed in the chronic METH group. The metabolome revealed that the main differential metabolites impacted were associated with glycolysis and glucose metabolism. The mRNA and protein expression of GLUT1, HK1, and LDHC were reduced in the chronic METH group but elevated in the short-term METH group, whereas HIF1alpha was upregulated in the short-term METH group but remained at baseline in the chronic METH group. CONCLUSIONS Overall, glucose metabolism was regulated by HIF1alpha after short-term METH exposure. Reduced glycolysis in the testis led to impaired spermatogenesis after chronic METH exposure.

Bupropion promotes alterations in the spermatogenesis of mice and congenital malformations in the offspring

Bupropion hydrochloride (BUP) has been associated with male sexual dysfunction. The aim of this study was to evaluate the effects of BUP on the reproductive function of male mice and to evaluate offspring development. The mice were distributed into BUP group (40 mg kg−1) and control group (saline). On Day 35 of treatment the males were placed to mate with females and then killed on Day 46 for evaluation of reproductive function. On Day 18 of pregnancy, pregnant females were killed for evaluation of congenital malformations in the offspring. The BUP group showed a decrease in the Johnsen score (Control, 9.354 ± 0.092; BUP, 7.615 ± 0.147), Sertoli (Control, 5.623 ± 0.184; BUP, 4.215 ± 0.097) and Leydig (Control, 11.430 ± 0.817; BUP, 7.531 ± 0.213) cell counts, testosterone levels (Control, 783.5 ± 154.2 ng dL−1; BUP, 201.4 ± 54.8 ng dL−1) and sperm production (Control, 2.852 ± 0.211; BUP, 1.988 ± 0.116) and increased morphological alterations of the sperm head (Control, 8.134%; BUP, 10.423%) and tail (Control, 4.96%; BUP, 16.211%). The congenital malformations observed in BUP-derived offspring were: kyphosis (Control, 0.00%; BUP, 5.26%), retroverted rear legs (Control, 14.43%; BUP, 53.68%), incomplete ossification of the supraoccipital and exoccipital (Control, 21.82%; BUP, 86.00%) and sternum (Control, 25.45%; BUP, 82.00%). BUP had toxic effects on testicular function and teratogenic potential.

GABAergic Alterations in the Rat Testis after Methamphetamine Exposure

Gamma-aminobutyric acid (GABA), GABA-A receptors and GABA transporter 1 (GAT1) were reported to be involved in the proliferation of Leydig cells, testosterone production and spermatogenesis. Since methamphetamine (METH) has been reported to have adverse effects on testis and its functions, the aim of this study was therefore to determine the changes of GABAergic activity in testis after METH exposure. Male Sprague-Dawley rats were divided into control, acute binge (AB-METH), escalating dose (ED METH) and escalating dose-binge (ED-binge METH) groups. After sacrifice, rat testes were removed and used to estimate GABA concentration and the expression of GABA-A receptor, GAD1, GAD2 and GAT1 genes by using HPLC and RT-PCR, respectively. The GABA concentration was significantly increased in all METH-administrated groups. In addition, significant increases of GABA-A α1 receptor and GAD1 genes expression were found in the ED-binge METH group. Gene expressions of GAT1 were numerically decreased in all METH-administrated rats and reached significant in the ED METH group. These results indicated a compensatory upregulation of GABA production and its functions in testis after METH exposure. Thus, these changes might represent a homeostatic response of GABAergic to the adverse effects of METH.

Understanding the link between antimicrobial properties of dietary olive phenolics and bacterial ATP synthase

The naturally occurring olive phenolics tyrosol, hydroxytyrosol, dihydroxyphenylglycol (DHPG), and oleuropein are known to have antioxidant, antitumor, and antibacterial properties. In the current study, we examined whether the antimicrobial properties of tyrosol, hydroxytyrosol, DHPG, and oleuropein were linked to the inhibition of bacterial ATP synthase. Tyrosol, hydroxytyrosol, DHPG, and oleuropein inhibited Escherichia coli wild-type and mutant membrane-bound F1Fo ATP synthase to variable degrees. The growth properties of wild-type, null, and mutant strains in presence of above olive phenolics were also abrogated to variable degrees on limiting glucose and succinate. Tyrosol and oleuropein synergistically inhibited the wild-type enzyme. Comparative wild-type and mutant F1Fo ATP synthase inhibitory profiles suggested that αArg-283 is an important residue and olive phenolics bind at the polyphenol binding pocket of ATP synthase. Growth patterns of wild-type, null, and mutant strains in the presence of tyrosol, hydroxytyrosol, DHPG, and oleuropein also hint at the possibility of additional molecular targets. Our results demonstrated that ATP synthase can be used as a molecular target and the antimicrobial properties of olive phenolics in general and tyrosol in particular can be linked to the binding and inhibition of bacterial ATP synthase.