Physiological Reports最新文献

FAM20C, a member of the family with sequence similarity 20, is involved in many physiological functions. Obesity, characterized by excessive accumulation of adipose tissue, has attracted more and more attention as a worldwide health problem. Here we generated adipocyte-specific FAM20C knockout mice to investigate the role of FAM20C in adipose tissue expansion and obesity. Our results demonstrate that knockout mice are protected against high fat diet-induced obesity, adiposity, and fatty liver disease. Additionally, knockout mice exhibited improved metabolic phenotypes, including enhanced glucose tolerance and insulin sensitivity compared with control mice. Furthermore, we observed reduced inflammatory infiltration and collagen deposition in the adipose tissues of knockout mice. Taken together, our results indicate that targeting FAM20C in adipocytes may be a promising strategy for the treatment of obesity and associated metabolic disorders.

The gustatory system plays an important role in evaluating food quality in animals and humans. While some tastes are intrinsically appetitive, such as sweet, which is elicited from high-calorie nutrients, the other tastes, such as sour and bitter, are aversive and elicited by toxic substances. In mice, taste signals are relayed by multiple regions of the brain, including the nucleus of the solitary tract, and the parabrachial nucleus (PBN) of the pons, before reaching the gustatory cortex via the gustatory thalamus. Recent advances in taste research using mice expressing Cre recombinase in specific neuronal populations, together with chemogenetic/optogenetic tools, have enabled us to identify genetically defined neurons involved in taste transduction pathways across several areas of the brain. While gustatory pathways play a fundamental role in taste transduction, taste preferences are not always stable, but rather vary depending on internal states. This review summarizes recent progress in research on neural circuits that modify the taste information depending on internal states in mice.

Redox reactions, involving electron transfer, are critical to human physiology. However, progress in understanding redox metabolism is hindered by flawed analytical methods. This review highlights emerging techniques that promise to revolutionize redox research, enhancing our comprehension of human health and disease. Oxygen, vital for aerobic metabolism, also produces reactive oxygen species (ROS), such as superoxide and hydrogen peroxide. While historically seen as harmful, ROS at low concentrations are now recognized as key regulators of cell signaling. A balance between ROS and antioxidants, known as redox balance, is crucial, and deviations can lead to oxidative stress. Recent studies have distinguished beneficial "oxidative eustress" from harmful "oxidative distress." New techniques, such as advanced mass spectrometry and high-throughput immunoassays, offer improved accuracy in measuring redox states and oxidative damage. These advancements are pivotal for understanding redox signaling, cysteine oxidation, and their implications for disease. Looking ahead, the development of precision redox medicine could lead to better treatments for oxidative stress-related diseases and foster interventions promoting health.

Acquiring sufficient blood for hormone analysis in mice can be a limiting step. Hormone analysis techniques using non-invasive sample collection have been vigorously developed for endangered species, from whom blood sampling is prohibited, or from species that are otherwise difficult to handle in a laboratory setting. Because there are interactions between glucocorticoids and thyroid hormones (T3 and T4), reducing the animal's "distress" during sample collection is imperative. Measurement of fecal T3 provides less sensitive, baseline information regarding thyroid function while permitting a non-invasive technique for more frequent sampling. We demonstrated that using a methanol extraction protocol produced the most reliable fecal T3 measurement in an enzyme-linked immunosorbent assay (ELISA). We found that during a thyroid hormone-treated state, fecal and plasma T3 measurements from mice are directly related, while during a methimazole-treated state, fecal and plasma T3 measurements from mice are inversely related. Fecal samples are a useful way to monitor thyroid hormone function in laboratory mice.

Previous studies based on animal models have raised concerns about salbutamol use in ozone air pollution with regard to ozone related lung injury. We conducted a double-blind, randomized, placebo-controlled crossover study including 18 subjects diagnosed with EIB by a eucapnic voluntary hyperpnea (EVH) test. Participants completed 30 min of standardized moderate to vigorous exercise in four conditions: ozone plus salbutamol; room air plus salbutamol; ozone plus placebo medication; and room air plus placebo medication. Spirometry, fraction of exhaled nitric oxide, and symptoms were measured before, immediately after, 30 min after and 1 h after exercise. Measurements between the four conditions were compared using percent change from pre to post exercise. There was a statistically significant difference between the salbutamol and placebo medication groups for spirometric variables including FEV1 (Estimate = 6.3, 95% CI: 4.23-8.37, p < 0.001). No differences were observed between ozone and room air exposures. There were no significant differences in FeNO response between experimental conditions. We found that salbutamol improved pulmonary function in individuals with EIB when exercising in ozone and did not increase eosinophilic airway inflammation as indicated by FeNO. This evidence suggests that it is safe for people with EIB to continue to use salbutamol as proscribed when ozone levels are elevated.

The Stop Signal Task (SST) has been the benchmark for studying the behavioral and physiological basis of movement generation and inhibition. In our study, we extended the scope beyond physiological findings related to muscle activity, focusing our analysis on the initial biomechanical state of the effector. By incorporating a force sensitive resistor (FSR), we continuously monitored the force applied by the effector (here, the index finger) during a button release version of the SST. This modified task design allowed us to examine both the baseline force before the relevant Go signal was presented and during the covert state of movement preparation. Notably, variations in force over time in response to the Go signal revealed differences across trials where movement was either generated or successfully inhibited, depending on the amount of force during the baseline period. Specifically, higher baseline force was associated with a delayed movement generation, which, simultaneously slowed down the force release, facilitating successful inhibition when requested. Our results highlight the influence of biomechanical variables in movement control, which should be accounted for by the models developed for investigating the physiology of this ability.

Peripheral nerve damage can cause debilitating symptoms ranging from numbness and pain to sensory loss and atrophy. To uncover the underlying mechanisms of peripheral nerve injury, our research aims to develop a relationship between biomechanical peripheral nerve damage and function through finite element modeling. A noncontact, ex vivo electrophysiology chamber, capable of axially stretching explanted nerves while recording electrical signals, was used to investigate peripheral nerve injury. Successive stretch trials were run on eight sciatic nerves (four females and four males) excised from Sprague-Dawley rats. Nerves were stretched until 50% compound action potential (CAP) amplitude reduction was obtained. A constitutive model developed by Raghavan and Vorp was suitable for rat sciatic nerves, with an average α and β of 0.183 MPa and 1.88 MPa, respectively. We then generated 95% confidence intervals for the stretch at which specific CAP amplitude reductions would occur, which compares well to previous studies. We also developed a finite element model that can predict stretch-induced signaling deficits, applicable for complex nerve geometries and injuries. This relationship between nerve biomechanics and function can be expanded upon to create a clinical model for peripheral nerve dysfunction due to stretch.

Fuel dispensing at fuel stations is performed manually by unprotected male gas station attendants in Sri Lanka, who have long working hours. These workers are exposed to hydrocarbon fuels associated with multiple health effects by modulation of the autonomic nervous system. This study was performed to determine cardiovascular autonomic functions among fuel pump attendants in Sri Lanka. Fuel pump attendants (n = 50) aged between 19 and 65 years were identified for the study from seven fuel stations. They were compared with age- and gender-matched controls (n = 46) without occupational exposure to fuel. A physical examination was performed before the autonomic function and heart rate variability (HRV) assessment. There were no significant differences in weight, height, or BMI between the study and the control populations (p > 0.05). Both the systolic blood pressure (SBP) (Mann Whitney U (MWU) = 743.5, p = 0.003) and diastolic blood pressure (DBP) (MWU = 686.5, p = 0.001) were significantly higher among the gas station attendants compared to controls. Valsalva ratio was significantly higher among the study group (MW U = 874.00, p = 0.043) compared to controls. The HRV analysis showed significantly higher SDNN and SD2 (MWU = 842.00, p = 0.034, and MWU = 843.50, p = 0.035 respectively) among the gas station attendants compared to controls. The changes to the cardiovascular autonomic parameters among those exposed to fuel vapor as a gas station attendant indicate an increase in sympathetic outflow to the vessels. In the occupational setting as fuel pump attendants need periodic monitoring.

"Medical scientists" are postgraduate investigators who are engaged in biomedical research, and either hold a biomedical PhD or are qualified in medicine but do not participate in patient care. Medical scientists constitute ~40% of staff at medical faculties and >90% at nonuniversity medical research institutions in Germany. However, medical scientists in Germany face limited long-term career prospects and a lack of dedicated training and support programmes. They also face time limits on their career progression arising from national academic employment legislation, and imminent reforms by the German government are likely to make this worse. Nevertheless, recent developments in the educational landscape including the introduction of increasingly focused MSc, pre-PhD, and doctoral programmes to train medically aware basic scientists, as well as improved general recognition of the roles and relevance of medical scientists in health research, are encouraging. Physiologists have taken essential steps to improve the recognition of medical scientists in Germany by introducing a "specialist physiologist" qualification; this initiative could be applied to support medical scientists in other fields and countries. In this review, we describe the particular challenges facing medical scientists in Germany and make recommendations that may apply to other academic systems.

Preeclampsia (PE) is characterized by de novo hypertension (HTN) and is often associated with intrauterine growth restriction (IUGR). Hallmarks of PE are placental ischemia, decreased nitric oxide (NO) bioavailability, oxidative stress (OS), and organ damage in the kidneys and brain. This study aims to characterize a new model of PE using pregnant IUGR rats from hypertensive placental ischemic dams. It is hypothesized that pregnant IUGR rats from hypertensive placental ischemic dams will have elevated blood pressure (BP), OS, and organ damage. In this study, pregnant rats are divided into two groups: normal pregnant (NP) and hypertensive placental ischemic dams (RUPP). Offspring from NP and RUPP dams were mated at 10 weeks of age to generate pregnant IUGR (IUGR Preg) and pregnant control (CON Preg) rats. BP and other markers of PE were evaluated during late gestation. Pregnant IUGR rats had elevated BP and systemic OS. The maternal body weight of pregnant IUGR rats and their pups' weights were decreased, while the brains were enlarged with elevated OS. In summary, pregnant IUGR rats, born from hypertensive placental ischemic dams, have HTN and increased systemic and brain OS, with larger brain sizes and smaller pups. Furthermore, this study shows that pregnant IUGR rats exhibit a preeclamptic-like phenotype, suggesting a new epigenetic model of PE.