β(2)-Adrenergic activity of 6-methoxykaempferol-3-O-glucoside on rat uterus: in vitro and in silico studies

Using cyproterone acetate to treat recurrent ischemic priapism in a patient with sickle cell anemia as a comorbidity: a case report

Introduction

The management of recurrent ischemic priapism is unclear in contemporary practice. Yet, if left untreated, the condition may evolve into an acute ischemic priapism and in some cases result in erectile dysfunction. This report documents the results of successful management of recurrent ischemic priapism using cyproterone acetate in a 30-year-old Saudi man with sickle cell anemia as a comorbidity.

Case presentation

A 30-year-old Saudi man denoted visited the emergency room with a painful erection which had lasted for more than four hours. The patient has sickle cell anemia and a family history of sickle cell disease. He is married and has two children. His first priapism case occurred when he was 7 years old. At the age of 15, the condition recurred, and the patient’s doctor prescribed cyproterone acetate 50 mg twice daily for 5 days. The doctor had told him that whenever he was experiencing priapism, he should adhere to this regimen for 5 days. The doctor could not find any guidelines for the prescription of cyproterone acetate.

Conclusion

Priapism cases represent a significant challenge in therapeutic management because of the elevated risk of structural damage to the penis. The fact that there lacks a clinically approved standard approach to managing the condition make it difficult for physicians to effectively manage the condition. Management of the condition is further complicated by existence of comorbidities such as sickle cell anemia. This patient’s case demonstrates that cyproterone acetate prescription is a great preventative strategy that limits priapism recurrences.

Structural and pharmacological basis for the induction of mitochondrial biogenesis by formoterol but not clenbuterol

Mitochondrial dysfunction is associated with numerous acute and chronic degenerative diseases. The beta-2 adrenergic receptor (β₂AR) agonist formoterol induces mitochondrial biogenesis (MB), but other β₂AR agonists, such as clenbuterol, do not. We sought to identify the MB signaling pathway of formoterol and the differences in signaling between these two ligands that result in the differential induction of MB. While formoterol and clenbuterol increased cAMP, only formoterol increased the phosphorylation of Akt and its downstream target eNOS. The increase in Akt phosphorylation was Gβγ- and PI3K-dependent, and the increase in eNOS phosphorylation was Gβγ- and Akt-dependent. Only formoterol increased cGMP. Formoterol induced MB as measured by increases in uncoupled cellular respiration and PGC-1α and NDUFS1 mRNA expression and was blocked by inhibitors of Gβγ, Akt, NOS, and soluble guanylate cyclase. To identify distinct receptor-ligand interactions leading to these differences in signaling, we docked formoterol and clenbuterol to six structures of the β₂AR. Compared to clenbuterol, the methoxyphenyl group of formoterol interacted more frequently with V114 and F193, while its formamide group interacted more frequently with C191. These data indicate that the unique structural features of formoterol allow it to interact with the β₂AR to activate the Gβγ-Akt-eNOS-sGC pathway to induce MB.

Time and dose relationships between schisandrin B- and schisandrae fructus oil-induced hepatotoxicity and the associated elevations in hepatic and serum triglyceride levels in mice

Background

Schisandrin B (Sch B), a dibenzocyclooctadiene compound, is isolated from schisandrae fructus (SF). This study was conducted to compare the time- and dose-response between Sch B- and SF oil (SFO)-induced changes in hepatic and serum parameters in mice.

Methods

Institute of Cancer Research (ICR) mice were given a single oral dose of Sch B (0.125–2 g/kg) or SFO (0.3–5 g/kg). Serum alanine aminotransferase (ALT) activity, hepatic malondialdehyde, and triglyceride (TG) levels were measured at increasing time intervals within 6–120 hours postdosing.

Results

Serum ALT activity was elevated by 60%, with maximum effect (E_max) =45.77 U/L and affinity (K_D) =1.25 g/kg at 48–96 hours following Sch B, but not SFO, treatment. Sch B and SFO treatments increased hepatic malondialdehyde level by 70% (E_max =2.30 nmol/mg protein and K_D =0.41 g/kg) and 22% (E_max =1.42 nmol/mg protein and K_D =2.56 g/kg) at 72 hours postdosing, respectively. Hepatic index was increased by 16%–60% (E_max =11.01, K_D =0.68 g/kg) and 8%–32% (E_max =9.88, K_D =4.47 g/kg) at 12–120 hours and 24–120 hours after the administration of Sch B and SFO, respectively. Hepatic TG level was increased by 40%–158% and 35%–85%, respectively, at 12–96 hours and 6–48 hours after Sch B and SFO treatment, respectively. The values of E_max and K_D for Sch B/SFO-induced increase in hepatic TG were estimated to be 22.94/15.02 μmol/g and 0.78/3.03 g/kg, respectively. Both Sch B and SFO increased serum TG (up to 427% and 123%, respectively), with the values of E_max =5.50/4.60 mmol/L and K_D =0.43/2.84 g/kg, respectively.

Conclusion

The findings indicated that Sch B/SFO-induced increases in serum/hepatic parameters occurred in a time-dependent manner, with the time of onset being serum TG level < hepatic TG level < hepatic index < serum ALT activity. However, the time of recovery of these parameters to normal values varied as follow: serum TG level < hepatic TG level and liver injury < hepatic index. The E_max and affinity of Sch B on tissue/enzyme/receptor were larger than those of SFO.

Medical management of ischemic stuttering priapism: a contemporary review of the literature

Priapism is defined as a prolonged and persistent erection of the penis without sexual stimulation. This is a poorly understood disease process with little information on the pathophysiology of this erectile disorder. Complications from this disorder are devastating due to the irreversible erectile damage and resultant erectile dysfunction (ED). Stuttering priapism, though relatively rare, affects a high prevalence of men with sickle-cell disease (SCD) and presents a challenging problem with guidelines for treatment lacking or resulting in permanent ED. The mechanisms involved in the development of priapism in this cohort are poorly characterized; therefore, medical management of priapism represents a therapeutic challenge to urologists. Additional research is warranted, so we can effectively target treatments for these patients with prevention as the goal. This review gives an introduction to stuttering priapism and its clinical significance, specifically with regards to the patient with SCD. Additionally, the proposed mechanisms behind its pathophysiology and a summary of the current and future targets for medical management are discussed.