Pharmacology最新文献

Introduction: Complex spikes (CSs) activity of cerebellar Purkinje cells plays critical roles in motor coordination and motor learning by transferring information to cerebellar cortex, which is an accessible and useful model for neurophysiological investigation. Etomidate is an ultrashort-acting nonbarbiturate intravenous anesthetic, which inhibits the spontaneous activity of cerebellar Purkinje cells through activation of GABAA and glycine receptors in vivo in mice. However, the effect of etomidate on the spontaneous CSs activity of cerebellar Purkinje cells in living mouse is not clear.

Methods: We here investigated the effects of etomidate on spontaneous CSs activity of cerebellar Purkinje cell in urethane-anesthetized mice by electrophysiology recording technique and pharmacological methods.

Results: Our results showed that cerebellar surface perfusion of etomidate significantly depressed the activity of spontaneous CSs, which exhibited decreases in the number of spikelets and the area under curve (AUC) of the CSs. The etomidate-produced inhibition of CSs activity was persisted in the presence of GABAA and glycine receptors antagonists. However, application of cannabinoid 1 (CB1) receptor antagonist, AM-251, completely blocked the etomidate-induced inhibition of CSs. Furthermore, application of the CB1 receptor agonist, WIN55212-2, induced a decrease of CSs. Moreover, in the presence of a specific protein kinase A (PKA) inhibitor, KT5720, etomidate failed to produce decreases in the spikelets number and the AUC of the spontaneous CSs.

Conclusion: These results indicate that cerebellar surface application of etomidate facilitates CB1 receptor activity resulting in a depression of spontaneous CSs activity of Purkinje cells via PKA signaling pathway in mouse cerebellar cortex. Our present results suggest that the etomidate administration may impair the function of cerebellar cortical neuronal circuitry by inhibition of the climbing fiber - Purkinje cells synaptic transmission through activation of CB1 receptors in vivo in mice.

Introduction: The aim of this study was to investigate the effect of canagliflozin (CANA) on ventricular remodeling in patients with preserved ejection fraction (HFpEF) heart failure and to further investigate its possible molecular mechanisms.

Methods: A high-salt diet was used to induce the formation of HFpEF model in salt-sensitive rats. The rats were fed with CANA and irbesartan, respectively. The mice were divided into control group, model group, CANA group, irbesartan group, and combined drug group. After 12 weeks of feeding, the rats were evaluated by measuring the relevant indexes and echocardiography for cardiac function. Histological analysis was performed using Masson trichrome staining and immunohistochemical staining. RT-qPCR and Western blot were used to quantify the relevant genes and proteins.

Results: In this study, CANA exhibited diuresis, decreased blood pressure, weight loss, and increased food and water intake. Following a high-salt diet, Dahl salt-sensitive rats developed hypertension followed by left ventricular diastolic dysfunction, myocardial fibrosis, and left ventricular remodeling. Myocardial hypertrophy and fibrosis were reduced, and left ventricular diastolic function and ventricular remodeling improved after CANA treatment. The combination of CANA and irbesartan was superior to monotherapy in reducing blood pressure and improving cardiac insufficiency and left ventricular diastolic dysfunction in rats. CANA improves myocardial fibrosis, left ventricular diastolic dysfunction, and ventricular remodeling by upregulating apelin, activating angiotensin-converting enzyme 2 (ACE2), and increasing ACE2/Ang (1-7)/MASR axis levels.

Conclusion: CANA improves myocardial fibrosis, left ventricular diastolic dysfunction, and ventricular remodeling in HFpEF rats through upregulation of apelin/ACE2 signaling.

Background: Autophagy is a lysosome-mediated catabolic process that maintains cell homeostasis and survival. It occurs not only in normal cells such as cardiac muscle cells, neurons, and pancreatic acinar cells but also in various benign and malignant tumors. The abnormal level of intracellular autophagy is closely related to multiple pathophysiological processes, including aging, neurodegeneration, infectious diseases, immune disorders, and cancer. Autophagy mainly plays a dual role in life and death by regulating cell survival, proliferation, and death, thus being involved in the occurrence, development, and treatment of cancer. It is also involved in chemotherapy resistance by a dual role, since it not only promotes the occurrence of drug resistance but also reverses it. Previous findings suggest that the regulation of autophagy can be used as an effective strategy in tumor therapy.

Summary: Recent studies found that small molecules from natural products and their derivatives exert anticancer activity by regulating the level of autophagy in tumor cells.

Key messages: Therefore, this review article describes the mechanism of autophagy, the role of autophagy in normal cells and tumor cells, and the research progress on the anticancer molecular mechanism of targets regulating cell autophagy. The aim is to provide a theoretical basis for developing autophagy inhibitors or activators to improve anticancer efficacy.

Introduction: Autoimmune thyroiditis seems to be associated with increased cardiometabolic risk. Statins, the mainstay of cardiovascular risk reduction and prevention, were found to reduce thyroid antibody titers. The aim of this study was to investigate plasma markers of cardiometabolic risk in statin-treated women with thyroid autoimmunity.

Methods: We compared two matched groups of euthyroid women with hypercholesterolemia receiving atorvastatin treatment: subjects with autoimmune (Hashimoto's) thyroiditis (group A, n = 29) and subjects without thyroid pathology (group B, n = 29). Plasma lipids, glucose homeostasis markers, as well as circulating levels of uric acid, high-sensitivity C-reactive protein (hsCRP), fibrinogen, homocysteine, and 25-hydroxyvitamin D were measured before atorvastatin treatment and 6 months later.

Results: At entry, both groups differed in antibody titers, insulin sensitivity, and plasma levels of uric acid, hsCRP, fibrinogen, homocysteine, and 25-hydroxyvitamin D. Atorvastatin-induced reduction in hsCRP and homocysteine, but not in total cholesterol and LDL-cholesterol, was more pronounced in group B than in group A. Only in group B, the drug decreased uric acid and fibrinogen and increased 25-hydroxyvitamin D. In group A, atorvastatin reduced insulin responsiveness.

Conclusion: The obtained results indicate that euthyroid women with Hashimoto's thyroiditis may benefit to a lesser degree from atorvastatin treatment than other populations of women with hypercholesterolemia.

Background: Acute kidney injury (AKI) is a common and potentially fatal complication encountered during a variety of kidney surgeries. Renal ischemia/reperfusion (I/R) injury is the predominant mechanism of AKI in this setting. Hence, controlling I/R injury is a key research imperative as it is directly related to the prognosis of patients.

Summary: In the last decade, studies in vitro and in animal models have demonstrated that flavonoids can significantly alleviate I/R-induced AKI through a variety of pathways, including anti-oxidative stress, anti-inflammation, anti-cell death, inhibition of endoplasmic reticulum stress, and alleviation of mitochondrial dysfunction. Based on the extensive role of flavonoids in ischemia-reperfusion injury, the lack of drugs entering the clinic so far is a question worthy of consideration.

Key messages: This review summarizes the available evidence pertaining to the protective effect of flavonoids against renal I/R injury and discusses their potential clinical application in renal I/R injury.

Introduction: Cisplatin is extensively used in the treatment of head and neck carcinomas. Cetuximab combination therapy is employed in recurrent and metastatic settings. Sunitinib showed positive results in the treatment of head and neck carcinomas, both as monotherapy or in combination with cetuximab. Nonetheless, the mechanism governing these pharmacological interactions is largely unresolved. This study investigates the impact of cetuximab on the cytotoxicity of cisplatin and sunitinib using cells representative of head and neck carcinoma and the oral epithelium.

Methods: The uptake and efflux activities of cells were determined using the prototypical fluorescent substrates 4-[4-[dimethylamino]styryl)-1-methyl pyridinium iodide, Hoechst 33342, and calcein-AM in the presence or absence of specific inhibitors in cells pretreated with cetuximab. The expression of key uptake and efflux drug transporters was analyzed using qPCR and immunofluorescence. Cisplatin and sunitinib cytotoxicities after cetuximab pretreatment were evaluated using the PrestoBlue viability assay.

Results: Both tumor and nontumor cells showed significant active drug transport activity. Cetuximab substantially deregulated the expression of key transporters involved in drug resistance in head and neck cancer cells. Transporter expression in the nontumor cell was unaffected. Upon cetuximab pretreatment, the half maximal effective toxic concentration of cisplatin was reduced by 0.75-fold and sunitinib by 0.82-fold in cancer cells. Nontumor cells were not sensitive to cisplatin or sunitinib under the conditions tested.

Conclusion: Cetuximab regulates the expression and activity of key membrane drug transporters in head and neck cancer cells, involved in drug resistance. The deregulation of the transport mechanism behind cisplatin and sunitinib uptake reverses drug resistance and enhances the cytotoxicity of both drugs.

Introduction: Our study aimed to investigate the effect of zonisamide (ZNS) on bone metabolism in the rat model.

Methods: Eight-week-old rats were divided into four groups. The sham-operated control group (SHAM) and the control group after orchidectomy (ORX) received the standard laboratory diet (SLD). The experimental group after orchidectomy (ORX+ZNS) and the sham-operated control group (SHAM+ZNS) received SLD enriched with ZNS for 12 weeks. Bone marker concentrations in serum of receptor activator of nuclear factor kappa B ligand, PINP, and osteoprotegerin, and the levels of sclerostin and bone alkaline phosphatase in bone homogenate, were measured using an enzyme-linked immunosorbent assay. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. The femurs were used for biomechanical testing.

Results: We found a statistically significant reduction in BMD and biomechanical strength 12 weeks after orchidectomy of the rats (ORX). After ZNS administration to orchidectomized rats (ORX+ZNS) and the sham-operated control rats (SHAM+ZNS), there were no statistically significant changes in BMD, bone turnover markers, or biomechanical properties as compared with the ORX group and SHAM group.

Conclusions: The results suggest that administration of ZNS to rats exerts no negative effect on BMD, bone metabolism markers, or biomechanical properties.