Amlodipine alone or combined with terazosin improves lower urinary tract disorder in rat models of benign prostatic hyperplasia or detrusor instability: focus on detrusor overactivity

Multi-omic approaches provide insights into the molecular mechanisms of Sojae semen germinatum water extract against overactive bladder

Sojae semen germinatum (SSG) is derived from mature soybean seeds that have been germinated and dried, typically with sprouts measuring approximately 0.5 cm in length. SSG is traditionally known for its properties in clearing heat and moisture. Nevertheless, limited information was reported on the effects and mechanisms of SSG in alleviating urinary symptoms. This study employed urodynamic parameters to investigate the therapeutic effect of SSG water extract on overactive bladder (OAB) in the rat model with benign prostatic hyperplasia. Through a combination of transcriptomic and metabolomic analyses, the pathways and key proteins of the SSG treatment for OAB were identified and validated by ELISA and Western blotting. Furthermore, network pharmacology elucidated the roles of SSG's isoflavones acting on the target which was identified by above-mentioned multi-omics analysis. Our results indicate that SSG water extract significantly mitigated OAB by down-regulating the PGE2/EP1/PLCβ2/p-MLC signaling pathway. It was speculated that the active ingredient in the SSG on EP1 was genistein. This study provided valuable insights into the molecular mechanisms of SSG water extract, emphasizing the multi-target characteristics and critical pathways in improving OAB. Furthermore, this study contributes to the potential utilization of SSG as a functional food.

Role of calcium channel blockers in lower urinary tract symptoms in benign prostatic hyperplasia: a literature review

Background

Benign prostatic hyperplasia (BPH) and the use of CCBs are common in older persons, and are also associated with lower urinary tract symptoms (LUTS). This review summarised and synthesised relevant information and recent advances to improve clinical knowledge on the role of CCBs in LUTS, BPH symptoms and health-related quality of life.

Main body of the abstract

A search of databases of PubMed, Web of science, Hinari, and Google scholar was performed using several keywords. Relevant studies were also extracted from references of identified studies. Selected studies were assessed for content related to CCBs, BPH and LUTS, and the most relevant reports were included. The inhibition of calcium channels by CCBs interferes with influx of extracellular Ca2+ into the detrusor muscle, which interferes with bladder contraction and relaxation. Hence, CCBs are associated with precipitation or aggravation of urinary storage and voiding symptoms, which are also common symptoms of BPH. This suggests a potential aggravation of BPH symptoms with the use of CCBs.

Short conclusion

Persons at high risk of LUTS such as in BPH, may benefit from other classes of antihypertensive drugs. Therefore, it is essential to identify persons with BPH prior to commencement of therapy with CCBs. Patients on CCBs should be routinely reviewed for any potential precipitation or aggravation of LUTS. Patients should also be counselled to notify their healthcare provider of unusual urinary symptoms during CCB use. This will facilitate enhanced quality of life in patients with BPH.

Hyperpolarization-activated cation currents in medium-size dorsal root ganglion cells are involved in overactive bladder syndrome in rats

BACKGROUND

To investigate the functions of the hyperpolarization-activated cation currents in medium-size dorsal root ganglion cells in a rat model of overactive bladder syndrome.

METHODS

Rats with OAB were screened using a urodynamic testing device. The whole-cell patch clamp technique was used to investigate changes in excitability and hyperpolarization-activated cation current (I_h) of medium-size cells in the L6 dorsal root ganglia (DRG) of the OAB rats. Intrathecal injection of the specific I_h inhibitor ZD7288 was used to investigate changes of voiding function and I_h of medium-size cells in the L6 DRG.

RESULTS

The urinary bladder weight of the OAB rats was significantly increased (p < 0.01); However, 7 days after intrathecally administration of ZD7288 (2 μM), the weight of rat bladder was significantly reduced (p < 0.01). The excitability of the medium-size cells in the L6 DRG of the OAB rats was significantly increased, and the number of action potentials elicited by a 500 pA stimulus was also markedly increased. Furthermore, ZD7288 significantly reduced the excitability of the medium-size DRG cells. The medium-size cells in the DRG of the OAB rats had a significantly increased I_h current density, which was blocked by ZD7288.

CONCLUSIONS

The I_h current density significantly increased in medium-size cells of the L6 DRG in the OAB model. A decrease of the I_h current was able to significantly improve the voiding function of the OAB rats, in addition to lowering their urinary bladder weight. Our finding suggested that the observed increase of I_h current in the medium-size DRG neurons might play an important role in the pathological processes of OAB.

The Influence of Maxacalcitol, Vitamin D3 Analog, on Detrusor Overactivity in Conscious Rats

OBJECTIVES

To test the hypothesis that maxacalcitol, vitamin D3 analog, would ameliorate detrusor overactivity (DO) induced by retinyl acetate instillation; to test the outcome of the combined administration of maxacalcitol and the rho kinase inhibitor - GSK 269962, amlodipine besylate, or oxybutynin chloride in this model.

METHODS

The rats were treated with maxacalcitol for 14 days. Then, cystometric studies were performed during which the animals were administered test compounds.

RESULTS

Maxacalcitol in a dose of 30 but not 15 µg/kg/day induced reduction in DO index, non-voiding contractions frequency (FNVC), and amplitude (ANVC), while increasing volume threshold to elicit non-voiding contractions (VTNVC). The 14-day-long administration of maxacalcitol at a dose of 15 µg/kg/day to animals, followed by GSK 269962 at a single dose of 10 mg/kg, led to a statistically significant reduction of intercontraction interval and bladder compliance, and an increase in DO index, without any effect on ANVC, FNVC, and VTNVC. The assessment of the combined effect of maxacalcitol (15 µg/kg/day) and amlodipine besylate (0.25 mg/kg) demonstrated an increase in intercontraction interval, bladder compliance and VTNVC, with a decrease in FNVC. No statistically significant changes were found in DO index and ANVC. The combined outcome of administering maxacalcitol (15 µg/kg/day) and oxybutynin chloride (0.25 mg/kg) did not show any statistically significant value of the measured cystometric parameters.

CONCLUSION

The outcomes of maxacalcitol administration can be the result of 3 mechanisms, that is, the upregulation of L-type Ca(2+) channels, the inhibition of the rho kinase pathway, and a so far unknown central mechanism.

LHRH antagonist Cetrorelix reduces prostate size and gene expression of proinflammatory cytokines and growth factors in a rat model of benign prostatic hyperplasia

BACKGROUND

Recent findings suggest that BPH has an inflammatory component. Clinical trials have documented that therapy with LHRH antagonist Cetrorelix causes a marked and prolonged improvement in LUTS in men with symptomatic BPH. We investigated the mechanism of action and effect of Cetrorelix in a rat model of BPH.

METHODS

Adult male Wistar rats were used. BPH was induced in rats by subcutaneous injections of TE 2 mg/day for 4 weeks. Control animals received injections of corn oil. After induction of BPH, rats received depot Cetrorelix pamoate at the doses of 0.625, 1.25, and 12.5 mg/kg on days 1 and 22 and TE-control rats received vehicle injections. Whole prostates were weighed and processed for RNA and protein. Real-time RT-PCR assays for numerous inflammatory cytokines and growth factors were performed. Quantitative analyses of prostatic LHRH receptor, LHRH, androgen receptor (AR) and 5α-reductase 2 were done by real-time RT-PCR and immunoblotting; serum DHT, LH, PSA, and IGF-1 by immunoassays.

RESULTS

mRNA levels for inflammatory cytokines IFN-γ, IL-3, IL-4, IL-5, IL-6, IL-8, IL-13, IL-15, and IL-17 and for growth factors EGF, FGF-2, FGF-7, FGF-8, FGF-14, TGF-β1, and VEGF-A were significantly reduced by Cetrorelix 0.625 mg/kg (P < 0.05). Prostate weights were also significantly lowered by any dose of Cetrorelix.

CONCLUSIONS

This study suggests that Cetrorelix reduces various inflammatory cytokines and growth factors in rat prostate and, at doses which do not induce castration levels of testosterone, can lower prostate weights. Our findings shed light on the mechanism of action of LHRH antagonists in BPH.

Antagonists of growth hormone-releasing hormone (GHRH) reduce prostate size in experimental benign prostatic hyperplasia

Growth hormone-releasing hormone (GHRH), a hypothalamic polypeptide, acts as a potent autocrine/paracrine growth factor in many cancers. Benign prostatic hyperplasia (BPH) is a pathologic proliferation of prostatic glandular and stromal tissues; a variety of growth factors and inflammatory processes are inculpated in its pathogenesis. Previously we showed that potent synthetic antagonists of GHRH strongly inhibit the growth of diverse experimental human tumors including prostate cancer by suppressing various tumoral growth factors. The influence of GHRH antagonists on animal models of BPH has not been investigated. We evaluated the effects of the GHRH antagonists JMR-132 given at doses of 40 μg/d, MIA-313 at 20 μg/d, and MIA-459 at 20 μg/d in testosterone-induced BPH in Wistar rats. Reduction of prostate weights was observed after 6 wk of treatment with GHRH antagonists: a 17.8% decrease with JMR-132 treatment; a 17.0% decline with MIA-313 treatment; and a 21.4% reduction with MIA-459 treatment (P < 0.05 for all). We quantified transcript levels of genes related to growth factors, inflammatory cytokines, and signal transduction and identified significant changes in the expression of more than 80 genes (P < 0.05). Significant reductions in protein levels of IL-1β, NF-κβ/p65, and cyclooxygenase-2 (COX-2) also were observed after treatment with a GHRH antagonist. We conclude that GHRH antagonists can lower prostate weight in experimental BPH. This reduction is caused by the direct inhibitory effects of GHRH antagonists exerted through prostatic GHRH receptors. This study sheds light on the mechanism of action of GHRH antagonists in BPH and suggests that GHRH antagonists should be considered for further development as therapy for BPH.