Dibutyl Phthalate Inhibits the Effects of Follicle-Stimulating Hormone on Rat Granulosa Cells Through Down-Regulation of Follicle-Stimulating Hormone Receptor.

Dibutyl phthalate (DBP) is used worldwide in solvents and plasticizers. The cytotoxicity and potential tumorigenic effect of DBP have been reported. DBP has also been shown to impact reproductive function. In this study, to further evaluate the effects of DBP on granulosa cells (GCs), we treated rat GCs in vitro with DBP before evaluation of the biological alterations of these GCs. We found that DBP did not induce significant GC death at the tested concentrations. However, follicle-stimulating hormone (FSH)-induced KIT ligand (KITLG) expression in GCs was significantly reduced at both mRNA and protein levels by DBP treatment in a dose-dependent manner. The down-regulation of KITLG was due to the down-regulation of expression of FSH receptor (FSHR) in GCs. Down-regulation of FSHR impaired FSH-induced intracellular signaling in GCs, demonstrated by decreased phosphorylation of AKT and mechanistic target of rapamycin (mTOR). Furthermore, DBP treatment also reduced FSH-induced expression of hypoxia-inducible factor 1-alpha (HIF1A), which is an important signaling component for KITLG expression. Other FSH-induced biological effects, such as production of estradiol and progesterone, as well as GC proliferation, were also suppressed by DBP. Therefore, our study discovered a unique mechanism underlying the toxicity of DBP on GCs. These findings may initiate the development of novel therapeutic interventions for DBP-induced damage to GCs.

Repeated platelet-rich plasma injections improve erectile dysfunction in a rat model of hyperhomocysteinemia.

ABSTRACT: Platelet-rich plasma (PRP) shows promise as a regenerative modality for mild-to-moderate erectile dysfunction (ED). However, its efficacy in treating severe ED remains unknown. Blood samples from 8-week-old male rats were used to prepare PRP through a two-step centrifugation procedure, followed by chitosan activation and freeze‒thaw cycle. A hyperhomocysteinemia (HHcy)-related ED model was established using a methionine-enriched diet, and an apomorphine (APO) test was conducted during the 4th week. APO-negative rats were divided into two groups and were injected with PRP or saline every 2 weeks. Erectile function and histological analyses of the corpus cavernosum were performed during the 16th week. The results revealed that erectile function was significantly impaired in rats with HHcy-related ED compared to that in age-matched rats but was improved by repeated PRP injections. Immunofluorescence staining revealed a reduction in reactive oxygen species and additional benefits on the recovery of structures within the corpus cavernosum in rats that received PRP treatment compared to those in the saline-injected control group. Therefore, PRP could enhance functional and structural recovery in a severe HHcy-related ED model. A notable strength of the present study lies in the use of a repeated intracavernous injection method, mirroring protocols used in human studies, which offers more reliable results for translating the findings to humans.