β1- and β2-adrenergic receptor stimulation differ in their effects on PGC-1α and atrogin-1/MAFbx gene expression in chick skeletal muscle

Evaluation of the efficacy and safety of either or both mirabegron and silodosin, as a medical expulsive therapy for distal ureteric stones

OBJECTIVE

To evaluate efficacy and safety of either or both silodosin and mirabegron as MET for distal ureteric stones ≤ 10 mm.

PATIENTS AND METHODS

This study enrolled a total of 105 patients, aged between 20 and 56 years, diagnosed by single radiopaque distal ureteral stone measuring ≤ 10 mm. The recruitment period spanned from May 2020 to December 2021. The patients were randomly divided into three groups, with each group consisting of 35 participants. Group A received a once-daily dose of 8 mg of silodosin, group B received a once-daily dose of 50 mg of mirabegron, and group C received a combination of both medications. Treatment was administered to all patients until the stone was expelled or for a maximum duration of four weeks. The stone-free rate was determined by analyzing KUB films with or without ultrasonography.

RESULTS

The rate of stone expulsion was significantly higher in group C compared to groups A and B (P = 0.04 and P = 0.004, respectively). The mean (standard deviation) time for stone expulsion in groups A, B, and C was 14 ± 2.3 days, 11 ± 3.1 days, and 7 ± 2.2 days, respectively. Group C demonstrated a significantly shorter stone expulsion time compared to groups A and B (P = 0.001 and P = 0.04, respectively). The frequency of renal colic in group C was significantly lower than that in groups A and B, resulting in a reduced requirement for analgesics (P < 0.05). Anejaculation occurred at a significantly higher rate in the silodosin group (73.9%) and combination group (84%) compared to the mirabegron group (P < 0.05).

CONCLUSIONS

The findings of this study suggest that both silodosin and mirabegron are effective treatments for the expulsion of lower ureteric stones. Furthermore, the combination of these medications leads to an increased rate of stone expulsion and a reduced duration of expulsion.

Mirabegron in medical expulsive therapy for distal ureteral stones: a prospective, randomized, controlled study

OBJECTIVE

To observe the efficacy and safety of Mirabegron in patients with distal, ureteral stones ≤ 10 mm.

PATIENTS AND METHODS

A total of 90 patients with distal ureteral stones ≤ 10 mm were prospectively randomized into two groups. Forty-five cases in the study group and 45 cases as control. The stone-free rates (SFRs) and renal colic episodes between two groups were compared at the 1st, 2nd and 4th week end by imaging examinations.

RESULT

All of 90 patients were randomly assigned to two groups. In patients with ≤ 5 mm stones, the SFRs in the 1st week (63.6% vs. 33.3%, P = 0.040), the 2nd week (86.4% vs. 54.2%, P = 0.018), and the 4th week (90.9% vs. 66.7%, P = 0.046) after treatment were all significantly higher than that in the control group by the stratification analysis of stone size. Even though SFRs were all higher for patients with > 5 mm stones in study group, there was no statistically significant difference (All P > 0.05). In terms of renal colic episodes, the frequency of occurrence of the study group was significantly lower than that of the control group and need less antalgic.

CONCLUSIONS

The MET with Mirabegron has a significant role in improve SFR for the patients with distal ureteral stones ≤ 5 mm and no effect in > 5 mm stones. Furthermore, Mirabegron reduces the need for antalgic in ≤ 10 mm stones with low incidence of adverse effects.

Mirabegron, A Selective β3-Adrenoceptor Agonist Causes an Improvement in Erectile Dysfunction in Diabetic Rats

AIM

To investigate the possible beneficial effect of mirabegron [a selective β₃-adrenoceptor (AR) agonist] treatment on erectile dysfunction (ED) in streptozotocin-induced diabetic rats.

METHODS

Sprague-Dawley rats (n=20) were divided into two groups: control group and streptozotocin-induced diabetic group. In vivo erectile responses were evaluated after intracavernosal injection of mirabegron (0.4 mg/kg) in rats. The relaxation responses to electrical field stimulation (EFS, 10 Hz), sodium nitroprusside (SNP, 10 nM) and sildenafil (1 μM) of corpus cavernosum (CC) strips were examined after the incubation with mirabegron (10 μM). β₃-ARs expression and localization were determined by Western blot and immunohistochemical analyses in CC tissue.

RESULTS

In vivo erectile responses of diabetic rats [intracavernasal pressure (ICP) / mean arterial pressure, 0.17±0.01] were decreased, which were restored after administration of mirabegron (0.75±0.01, P<0.001). The basal ICP (7.1±0.6 mmHg) in diabetic rats was markedly increased after mirabegron (36.1 ±5.4 mmHg, P<0.01). Mirabegron caused markedly relaxation in diabetic rat CC after phenylephrine precontraction. The relaxation responses to EFS and sildenafil were reduced in diabetic CC, which were increased in the presence of mirabegron. Mirabegron enhanced SNP-induced relaxation response in both groups. The expression and immunoreactivity of β₃-ARs localized to CC smooth muscle were observed in control and diabetic rats.

CONCLUSIONS

This is the first study to show that intracavernosal administration of mirabegron improved erectile function and neurogenic relaxation of CC in diabetic rats. These results may be supported by further studies using combinations of mirabegron and phosphodiesterase type 5 (PDE5) inhibitors for the treatment of diabetic ED, especially in patients who do not respond to PDE5 inhibitor therapy.

Beta2 -adrenoceptor agonist salbutamol increases protein turnover rates and alters signalling in skeletal muscle after resistance exercise in young men

KEY POINTS

Animal models have shown that beta₂ -adrenoceptor stimulation increases protein synthesis and attenuates breakdown processes in skeletal muscle. Thus, the beta₂ -adrenoceptor is a potential target in the treatment of disuse-, disease- and age-related muscle atrophy. In the present study, we show that a few days of oral treatment with the commonly prescribed beta₂ -adrenoceptor agonist, salbutamol, increased skeletal muscle protein synthesis and breakdown during the first 5 h after resistance exercise in young men. Salbutamol also counteracted a negative net protein balance in skeletal muscle after resistance exercise. Changes in protein turnover rates induced by salbutamol were associated with protein kinase A-signalling, activation of Akt2 and modulation of mRNA levels of growth-regulating proteins in skeletal muscle. These findings indicate that protein turnover rates can be augmented by beta₂ -adrenoceptor agonist treatment during recovery from resistance exercise in humans.

ABSTRACT

The effect of beta₂ -adrenoceptor stimulation on skeletal muscle protein turnover and intracellular signalling is insufficiently explored in humans, particularly in association with exercise. In a randomized, placebo-controlled, cross-over study investigating 12 trained men, the effects of beta₂ -agonist (6 × 4 mg oral salbutamol) on protein turnover rates, intracellular signalling and mRNA response in skeletal muscle were investigated 0.5-5 h after quadriceps resistance exercise. Each trial was preceded by a 4-day lead-in treatment period. Leg protein turnover rates were assessed by infusion of [¹³ C₆ ]-phenylalanine and sampling of arterial and venous blood, as well as vastus lateralis muscle biopsies 0.5 and 5 h after exercise. Furthermore, myofibrillar fractional synthesis rate, intracellular signalling and mRNA response were measured in muscle biopsies. The mean (95% confidence interval) myofibrillar fractional synthesis rate was higher for salbutamol than placebo [0.079 (95% CI, 0.064 to 0.093) vs. 0.066 (95% CI, 0.056 to 0.075%) × h^-1 ] (P < 0.05). Mean net leg phenylalanine balance 0.5-5 h after exercise was higher for salbutamol than placebo [3.6 (95% CI, 1.0 to 6.2 nmol) × min^-1  × 100 g_{Leg Lean Mass}^-1 ] (P < 0.01). Phosphorylation of Akt2, cAMP response element binding protein and PKA substrate 0.5 and 5 h after exercise, as well as phosphorylation of eEF2 5 h after exercise, was higher (P < 0.05) for salbutamol than placebo. Calpain-1, Forkhead box protein O1, myostatin and Smad3 mRNA content was higher (P < 0.01) for salbutamol than placebo 0.5 h after exercise, as well as Forkhead box protein O1 and myostatin mRNA content 5 h after exercise, whereas ActivinRIIB mRNA content was lower (P < 0.01) for salbutamol 5 h after exercise. These observations suggest that beta₂ -agonist increases protein turnover rates in skeletal muscle after resistance exercise in humans, with concomitant cAMP/PKA and Akt2 signalling, as well as modulation of mRNA response of growth-regulating proteins.