BACKGROUND: Angiotensin receptor neprilysin inhibitors (ARNIs), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers (BBs), and mineralocorticoid receptor antagonists (MRAs) are the cornerstones in treating heart failure with reduced ejection fraction (HFrEF). Sodium-glucose cotransporter 2 inhibitors (SGLT-2is) are included in HFrEF treatment guidelines. However, the effect of SGLT-2i and the five drugs on HFrEF have not yet been systematically evaluated. METHODS: PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs) from inception dates to September 23, 2022. Additional trials from previous relevant reviews and references were also included. The primary outcomes were changes in left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter/dimension (LVEDD), left ventricular end-systolic diameter/dimension (LVESD), left ventricular end-diastolic volume (LVEDV), and left ventricular end-systolic volume (LVESV), left ventricular end-systolic volume index (LVESVI), and left ventricular end-diastolic volume index (LVEDVI). Secondary outcomes were New York Heart Association (NYHA) class, 6-min walking distance (6MWD), B-type natriuretic peptide (BNP) level, and N-terminal pro-BNP (NT-proBNP) level. The effect sizes were presented as the mean difference (MD) with 95% confidence interval (CI). RESULTS: We included 68 RCTs involving 16,425 patients. Compared with placebo, ARNI + BB + MRA + SGLT-2i was the most effective combination to improve LVEF (15.63%, 95% CI: 9.91% to 21.68%). ARNI + BB + MRA + SGLT-2i (5.83%, 95% CI: 0.53% to 11.14%) and ARNI + BB + MRA (3.83%, 95% CI: 0.72% to 6.90%) were superior to the traditional golden triangle ACEI + BB + MRA in improving LVEF. ACEI + BB + MRA + SGLT-2i was better than ACEI + BB + MRA (-8.05 mL/m 2 , 95% CI: -14.88 to -1.23 mL/m 2 ) and ACEI + BB + SGLT-2i (-18.94 mL/m 2 , 95% CI: -36.97 to -0.61 mL/m 2 ) in improving LVEDVI. ACEI + BB + MRA + SGLT-2i (-3254.21 pg/mL, 95% CI: -6242.19 to -560.47 pg/mL) was superior to ARB + BB + MRA in reducing NT-proBNP. CONCLUSIONS: Adding SGLT-2i to ARNI/ACEI + BB + MRA is beneficial for reversing cardiac remodeling. The new quadruple drug "ARNI + BB + MRA + SGLT-2i" is superior to the golden triangle "ACEI + BB + MRA" in improving LVEF. REGISTRATION PROSPERO; No. CRD42022354792.
Humans ; Heart Failure/physiopathology* ; Stroke Volume/physiology* ; Angiotensin Receptor Antagonists/therapeutic use* ; Angiotensin-Converting Enzyme Inhibitors/therapeutic use* ; Sodium-Glucose Transporter 2 Inhibitors/therapeutic use* ; Randomized Controlled Trials as Topic ; Mineralocorticoid Receptor Antagonists/therapeutic use* ; Adrenergic beta-Antagonists/therapeutic use*

Mutations in ion channel genes have long been implicated in a spectrum of epilepsy syndromes. However, therapeutic decision-making is relatively complex for epilepsies associated with channelopathy. Therefore, in the present study, we used a patient-derived organoid model with a novel SCN2A mutation (p.E512K) to investigate the potential of utilizing such a model as a platform for preclinical testing of anti-seizure compounds. The electrophysiological properties of the variant Nav1.2 exhibited gain-of-function effects with increased current amplitude and premature activation. Immunofluorescence staining of patient-derived cortical organoids (COs) displayed normal neurodevelopment. Multielectrode array (MEA) recordings of patient-derived COs showed hyperexcitability with increased spiking and remarkable network bursts. Moreover, the application of patient-derived COs for preclinical drug testing using the MEA showed that they exhibit differential responses to various anti-seizure drugs and respond well to carbamazepine. Our results demonstrate that the individualized organoids have the potential to serve as a platform for preclinical pharmacological assessment.
Organoids/physiology* ; NAV1.2 Voltage-Gated Sodium Channel/genetics* ; Humans ; Anticonvulsants/pharmacology* ; Epilepsy/drug therapy* ; Mutation ; Cerebral Cortex/drug effects* ; Action Potentials/drug effects* ; Carbamazepine/pharmacology*

The aim of this study was to conduct in vivo experiments using laser speckle contrast imaging (LSCI) technology to investigate the effects of high salt diet on renal vascular reactivity in mice. LSCI is a technology for monitoring blood flow based on the laser speckle principle. It has been widely used to detect microcirculatory functions in tissues such as the skin and brain. The kidneys are located behind the peritoneum, and their position is easily affected by the movement of abdominal organs. Measuring renal microcirculation in a living individual is difficult. The present study used a self-made kidney cup to isolate the kidney and fix its position relatively, and then applied LSCI technology to explore the effect of high salt diet (8% Na⁺) on renal vascular reactivity in male and female mice in vivo. The results showed that a short-term high salt diet (1 week) did not affect the systolic blood pressure of the tail artery, while significantly increased glomerular filtration rate (GFR) and renal blood flow (RBF). Compared with the normal salt diet group, the high salt diet group showed a significant decrease in the ratio of post-occlusive reactive hyperemia (PORH) in male mice, while there was no significant change in the PORH ratio in female mice. These results suggest that, although a short-term high salt diet does not cause changes in blood pressure, it has already affected renal vascular reactivity and has gender differences in its effects. Furthermore, the present study provides a basis for renal microcirculation assessment using LSCI in vivo.
Animals ; Mice ; Male ; Female ; Kidney/blood supply* ; Renal Circulation/physiology* ; Laser Speckle Contrast Imaging ; Sodium Chloride, Dietary/adverse effects* ; Microcirculation/physiology* ; Mice, Inbred C57BL

OBJECTIVE: To investigate the variations in the expression of voltage-gated sodium (Na_v) channel subunits during development of rat cerebellar Purkinje neurons and their correlation with maturation of electrophysiological characteristics of the neurons. METHODS: We observed the changes in the expression levels of Na_V1.1, 1.2, 1.3 and 1.6 during the development of Purkinje neurons using immunohistochemistry in neonatal (5-7 days after birth), juvenile (12-14 days), adolescent (21-24 days), and adult (42-60 days) SD rats. Using whole-cell patch-clamp technique, we recorded the spontaneous electrical activity of the neurons in ex vivo brain slices of rats of different ages to analyze the changes of electrophysiological characteristics of these neurons during development. RESULTS: The expression of Na_V subunits in rat cerebellar Purkinje neurons showed significant variations during development. Na_V1.1 subunit was highly expressed throughout the developmental stages and increased progressively with age (P < 0.05). Na_V1.2 expression was not detected in the neurons in any of the developmental stages (P > 0.05). The expression level of Na_V1.3 decreased with development and became undetectable after adolescence (P < 0.05). Na_V1.6 expression was not detected during infancy, but increased with further development (P < 0.05). Na_V1.1 and Na_V1.3 were mainly expressed in the early stages of development. With the maturation of the rats, Na_V1.3 expression disappeared and Na_V1.6 expression increased in the neurons. Na_V1.1 and Na_V1.6 were mainly expressed after adolescence. The total Na_V protein level increased gradually with development (P < 0.05) and tended to stabilize after adolescence. The spontaneous frequency and excitability of the Purkinje neurons increased gradually with development and reached the mature levels in adolescence. The developmental expression of Na_V subunits was positively correlated with discharge frequency (r=0.9942, P < 0.05) and negatively correlated with the excitatory threshold of the neurons (r=0.9891, P < 0.05). CONCLUSION The changes in the expression levels of Na_V subunits are correlated with the maturation of high frequency electrophysiological properties of the neurons, suggesting thatmature Na_V subunit expressions is the basis of maturation of electrophysiological characteristics of the neurons.
Rats ; Animals ; Purkinje Cells/physiology* ; Rats, Sprague-Dawley ; Neurons ; Brain ; Sodium/metabolism*

INTRODUCTION: A physiological profiling study was conducted to evaluate thermal strain as well as fluid and electrolyte balances on heat-acclimatised men performing a 72-km route march in a field setting. METHODS: 38 male soldiers (age range 18-23 years) participated in the study, as part of a cohort that marched for 72 km, with loads for about 26 hours. Core temperature and heart rate sensors were used for the duration of the march. Fluid and food intake and output were monitored for the duration of the march. Blood samples were taken one day before the march (pre-march), immediately after the march (Post 1) and on the 15^th day after the march to ascertain recovery (Post 2) to assess fluid and electrolyte profiles. RESULTS: Mean core temperature was within safe limits, ranging from 37.1 to 38.1°C throughout the march. There was an overall decrease in serum sodium levels, a decline in serum sodium concentration in 28 participants and three instances of hyponatraemia (serum sodium concentration <135 mmol/L). CONCLUSION Our study found low thermal strain heat-acclimatised individuals during a 72-km route march. However, there was an overall decrease in serum sodium levels, even when the participants were allowed to drink ad libitum. Challenges of exercise-associated hyponatraemia during prolonged activities remain to be addressed.
Humans ; Male ; Adolescent ; Young Adult ; Adult ; Military Personnel ; Hyponatremia ; Water-Electrolyte Balance/physiology* ; Exercise/physiology* ; Sodium

Ion channels mediate ion transport across membranes, and play vital roles in processes of matter exchange, energy transfer and signal transduction in living organisms. Recently, structural studies of ion channels have greatly advanced our understanding of their ion selectivity and gating mechanisms. Structural studies of voltage-gated potassium channels elucidate the structural basis for potassium selectivity and voltage-gating mechanism; structural studies of voltage-gated sodium channels reveal their slow and fast inactivation mechanisms; and structural studies of transient receptor potential (TRP) channels provide complex and diverse structures of TRP channels, and their ligand gating mechanisms. In the article we summarize recent progress on ion channel structural biology, and outlook the prospect of ion channel structural biology in the future.
Ion Channel Gating ; physiology ; Ion Channels ; Voltage-Gated Sodium Channels ; chemistry ; metabolism

OBJECTIVE: To explore the characteristic changes of the peripheral chorda tympanic nerve (CT) electrophysiological responses to salty stimulus and other taste stimuli in rats with the conditioned taste aversion to saltiness. METHODS: Fourteen adult SD male rats were divided into a conditioned taste aversion to salty group (CTA) and a control group (Ctrl) (n=7/group). On the first day of the experiment, rats were given a 0.1 mol/L NaCl intake for 30 min, then, the rats in CTA and Ctrl groups were injected intraperitoneally with 2 ml of 0.15 mol/L LiCl and the same amount of saline respectively. On day 2, 3 and 4, the 30 min consumption of NaCl and distilled water was measured for both groups of rats. On the 4th day after the behavioral test of that day, CT electrophysiological recording experiments were performed on CTA rats and control rats. RESULTS: Compared with the rats in Ctrl group, the electrophysiological characteristics of CT in CTA group rats did not change significantly the responses to the series of NaCl and other four basic taste stimuli (P＞0.05). The amiloride, the epithelial sodium channel blocker, strongly inhibited the response of CT to NaCl in CTA and Ctrl group rats (P＜0.01). CONCLUSION The electrophysiological responses of CT to various gustatory stimuli do not significantly change in rats after the establishment of conditional taste aversion to the saltiness.
Amiloride ; pharmacology ; Animals ; Chorda Tympani Nerve ; physiology ; Conditioning, Classical ; Electrophysiological Phenomena ; Male ; Rats ; Rats, Sprague-Dawley ; Sodium Chloride ; Taste ; physiology

INTRODUCTION: Lactogenesis II (LaII) failure can be prevented in at-risk mothers with simple proactive interventions. In a randomised trial, we investigated the efficacy of early and regular breast milk expression in establishing LaII, using an electric double-breast pump. METHODS: Mothers with uncomplicated singleton deliveries were randomised to intervention (n = 31) or control (n = 29) groups. The former commenced breast milk expression with an electric pump within one hour of delivery and maintained regular expression with direct breastfeeding. Control mothers directly breastfed without regular pump expression. Expressed milk volumes were analysed for citrate, lactose, sodium and protein. RESULTS: Median time of LaII was Day 3 (interquartile range [IQR] 1 day) with intervention and on Day 4 (IQR 1 day) among controls (p = 0.03). Biochemical steady-state concentrations were achieved around early Day 4 (sodium, total protein) and Days 4-5 (citrate, lactose). Sodium, protein and lactose levels were similar in both groups over seven days, at 5.80 mM, 0.68 mM and -13.38 mM, respectively. Mean daily milk volume with intervention was 73.9 mL on Day 3 and 225.2 mL on Day 7, greater than controls (25.4 mL on Day 3 and 69.2 mL on Day 7; p < 0.2). Mean infant weights were similar on Day 8 at 3,477 g with intervention and 3,479 g among controls. CONCLUSION LaII is established by postnatal Day 3 with early initiation of regular breast milk expression, a useful intervention for mothers at risk of early-onset breastfeeding failure.
Adult ; Breast Feeding ; methods ; Breast Milk Expression ; methods ; Citrates ; analysis ; Female ; Humans ; Infant Formula ; Infant, Newborn ; Lactation ; physiology ; Milk, Human ; chemistry ; physiology ; Mothers ; Proteins ; analysis ; Sodium ; analysis ; Young Adult

Spinal α-motoneurons directly innervate skeletal muscles and function as the final common path for movement and behavior. The processes that determine the excitability of motoneurons are critical for the execution of motor behavior. In fact, it has been noted that spinal motoneurons receive various neuromodulatory inputs, especially monoaminergic one. However, the roles of histamine and hypothalamic histaminergic innervation on spinal motoneurons and the underlying ionic mechanisms are still largely unknown. In the present study, by using the method of intracellular recording on rat spinal slices, we found that activation of either H or H receptor potentiated repetitive firing behavior and increased the excitability of spinal α-motoneurons. Both of blockage of K channels and activation of Na-Ca exchangers were involved in the H receptor-mediated excitation on spinal motoneurons, whereas the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels were responsible for the H receptor-mediated excitation. The results suggest that, through switching functional status of ion channels and exchangers coupled to histamine receptors, histamine effectively biases the excitability of the spinal α-motoneurons. In this way, the hypothalamospinal histaminergic innervation may directly modulate final motor outputs and actively regulate spinal motor reflexes and motor execution.
Animals ; Histamine ; pharmacology ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels ; metabolism ; Motor Neurons ; drug effects ; physiology ; Rats ; Receptors, Histamine H2 ; metabolism ; Sodium-Calcium Exchanger ; metabolism

The voltage-gated Na channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
Animals ; Antibodies, Monoclonal ; therapeutic use ; Biotin ; metabolism ; Cells, Cultured ; Disease Models, Animal ; Female ; Ganglia, Spinal ; cytology ; HEK293 Cells ; Humans ; Hybridomas ; chemistry ; Hyperalgesia ; drug therapy ; Male ; Mice ; Mice, Inbred C57BL ; NAV1.5 Voltage-Gated Sodium Channel ; metabolism ; NAV1.7 Voltage-Gated Sodium Channel ; chemistry ; immunology ; metabolism ; Neuralgia ; drug therapy ; metabolism ; Protein Binding ; drug effects ; Recombinant Proteins ; biosynthesis ; therapeutic use ; Sensory Receptor Cells ; drug effects ; physiology