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The regulation of glucose-stimulated insulin secretion and glucose excursion has a sensory component that operates in a sex-dependent manner. Objective Here, we aim to dissect the basis of the sexually dimorphic interaction between sensory neurons and pancreatic β cells and its overall impact on insulin release and glucose homeostasis. Methods We used viral retrograde tracing techniques, surgical and chemodenervation models, and primary cell-based co-culture systems to uncover the biology underlying sex differences in sensory modulation of pancreatic β-cell activity. Results Retrograde transsynaptic labeling revealed a sex difference in the density of sensory innervation in the pancreas. The number of sensory neurons emanating from the dorsal root and nodose ganglia that project in the pancreas is higher in male than in female mice. Immunostaining and confocal laser scanning microscopy confirmed the higher abundance of peri-islet sensory axonal tracts in the male pancreas. Capsaicin-induced sensory chemodenervation concomitantly enhanced glucose-stimulated insulin secretion and glucose clearance in male mice. These metabolic benefits were blunted when mice were orchidectomized prior to the ablation of sensory nerves. Interestingly, orchidectomy also lowered the density of peri-islet sensory neurons. In female mice, capsaicin treatment did not affect glucose-induced insulin secretion nor glucose excursion and ovariectomy did not modify these outcomes. Interestingly, same- and opposite-sex sensory-islet co-culture paradigms unmasked the existence of potential gonadal hormone-independent mechanisms mediating the male-female difference in sensory modulation of islet β-cell activity. Conclusion Taken together, these data suggest that the sex-biased nature of the sensory control of islet β-cell activity is a result of a combination of neurodevelopmental inputs, sex hormone-dependent mechanisms and the potential action of somatic molecules encoded by the sex chromosome complement., Highlights • Pancreas-projecting sensory neurons are more abundant in males than in females. • Male sex hormones regulate the density of peri-islet sensory innervation in adulthood. • Male sex hormones regulate sensory modulation of β-cell activity and glucose clearance. • Sex chromosome mechanisms regulate sensory modulation of islet β-cell activity.

The micro-flowing water system can improve the flesh quality of freshwater fish using the traditional pond farming method. However, the mechanism of this phenomenon has not yet been explored. This study intends to examine the changes of metabolites in freshwater fish after treatment with the micro-flowing purification system (MFPS). The UPLC-QTOF/MS based metabolomics method was utilized to screen the metabolites and predict the major possible metabolic pathways after MFPS treatment. There were 377 types of metabolites identified in the fish muscle, of which 54-71 represented significant different metabolites identified during different stages of MFPS treatments. The main mechanism of MFPS treatment in improving the quality of grass carp fish muscle was investigated, and the MFPS treatment was shown to improve the flesh quality and the flavor of grass carp fish muscle. This study could provide the theoretical basis for improving the quality of aquatic products.

There is emerging evidence to support an important role for the transient receptor potential vanilloid type 1 (TRPV1) sensory innervation in glucose homeostasis. However, it remains unknown whether the glucoregulatory action of these afferent neurons is sex-biased and whether it is pancreatic β-cell-mediated. Objective We investigated in male and female mice whether denervation of whole-body or pancreas-projecting TRPV1 sensory neurons regulates adult functional β-cell mass and alters systemic glucose homeostasis. Methods We used a combination of pharmacological and surgical approaches to ablate whole-body or pancreatic TRPV1 sensory neurons and assessed islet β-cell function and mass, aspects of glucose and insulin homeostasis, and energy expenditure. Results Capsaicin-induced chemodenervation of whole-body TRPV1 sensory neurons improved glucose clearance and enhanced glucose-stimulated insulin secretion without alterations in β-cell proliferation and mass, systemic insulin sensitivity, body composition, and energy expenditure. Similarly, denervation of intrapancreatic TRPV1 afferents by pancreas intraductal injection of capsaicin or surgical removal of the dorsal root ganglia projecting into the pancreas lowered post-absorptive glucose levels and increased insulin release upon glucose stimulation. The beneficial effects of TRPV1 sensory denervation on glucose tolerance and β-cell function were observed in male but not female mice. Conclusion Collectively, these findings suggest that TRPV1 neurons regulate glucose homeostasis, at least partly, through direct modulation of glucose-induced insulin secretion and that this regulation operates in a sex-dependent manner., Highlights • Whole-body ablation of TRPV1 neurons increases insulin secretion and glucose clearance in male but not female mice. • Pancreas-selective ablation of TRPV1 neurons enhances insulin secretion and glucose clearance in male but not female mice. • Surgical removal of lower thoracic DRGs improves insulin secretion and glucose clearance in male but not female mice.