Gonadotropin Inhibitory Hormone and Its Receptor: Potential Key to the Integration and Coordination of Metabolic Status and Reproduction

Since its discovery as a novel gonadotropin inhibitory peptide in 2000, the central and peripheral roles played by gonadotropin-inhibiting hormone (GnIH) have been significantly expanded. This is highlighted by the wide distribution of its receptor (GnIH-R) within the brain and throughout multiple peripheral organs and tissues. Furthermore, as GnIH is part of the wider RF-amide peptides family, many orthologues have been characterized across vertebrate species, and due to the promiscuity between ligands and receptors within this family, confusion over the nomenclature and function has arisen. In this review, we intend to first clarify the nomenclature, prevalence, and distribution of the GnIH-Rs, and by reviewing specific localization and ligand availability, we propose an integrative role for GnIH in the coordination of reproductive and metabolic processes. Specifically, we propose that GnIH participates in the central regulation of feed intake while modulating the impact of thyroid hormones and the stress axis to allow active reproduction to proceed depending on the availability of resources. Furthermore, beyond the central nervous system, we also propose a peripheral role for GnIH in the control of glucose and lipid metabolism at the level of the liver, pancreas, and adipose tissue. Taken together, evidence from the literature strongly suggests that, in fact, the inhibitory effect of GnIH on the reproductive axis is based on the integration of environmental cues and internal metabolic status.

Trends in Obesity and Metabolic Status in Northern and Southern China Between 2012 and 2020

Background: The trends of obesity-associated metabolic status in Chinese are lacking, especially those from different regions.Objectives: To examine the trends of obesity and metabolic status among Chinese population in 2012–2020.Methods: In a series cross-sectional study, data on 256,782 participants surveyed between 2014 and 2020 in Beijing, northern China, and 697,170 participants surveyed between 2012 and 2020 in Hunan, southern China were analyzed. Anthropometrics, blood pressure measurements, and blood tests were performed according to standard protocols. Trends in obesity and metabolic status were evaluated using the Joinpoint software.Results: Based on age- and sex-standardized values, the mean BMI values in northern and southern participants were 23.94 (95% CI: 23.93, 23.95) and 23.68 (95% CI: 23.67, 23.69) kg/m2, respectively. Between 2014 and 2020, the overall obesity prevalence among northern participants increased from 12.70% (95% CI: 12.17, 13.23%) to 14.33% (95% CI: 13.97, 14.70%) (P = 0.009), mainly derived by the 20–39 and 40–59 age groups. Moreover, the prevalence of metabolically healthy obese significantly increased from 2.07% (95% CI: 1.84, 2.30%) to 4.33% (95% CI: 4.13, 4.53%) in Northerners. Between 2012 and 2020, no significant trend in obesity was found among overall southern participants, but the prevalence of metabolically unhealthy obese significantly increased from 5.36% (95% CI: 5.18, 5.54%) to 7.35% (95% CI: 7.11, 7.58%), mainly derived by the 20–39 and 40–59 age groups.Conclusions: The trends in obesity and metabolic status were different between southern and northern Chinese. A national weight control plan is needed in China, focusing on young and middle-aged population.

Effects of salinity and plant-based diet or animal-plant combination diet on the performance and metabolic status of juvenile Nile tilapia

The purpose of this study was to evaluate the effects of salinity and plant-based diet or animal-plant combination diet on the performance and metabolic status of juvenile Nile tilapia (Oreochromis niloticus). The experimental design was completely randomized in a 4 × 2 factorial scheme with four replicates. The treatments were established by the combination of salinities of 0, 10, 20, and 30 g L-1 with an animal-plant combination diet (AP) or plant-based diet (P). The replicates were 60 L tanks with 12 fish per tank. Diets were provided for 32 days, and the fish were fed three times a day (8, 12, and 17 h) until apparent satiety. Daily feed intake (DFI) was measured, body weight (BW) was recorded at the beginning and end of the trial, and total length (TL) and standard length (SL) were measured at the end of the trial. Average daily gain (ADG), specific growth rate (SGR), feed conversion ratio (FCR), and survival rate were calculated. After the biometric measurements were made at the end of the trial, blood samples were collected to determine the plasma concentrations of total protein (TP), glucose, cholesterol, and triglycerides (TG). The fish were euthanized, and the hepatopancreas was collected and weighed; thereafter, the hepatosomatic index (HSI) was calculated. An interaction was detected between salinity and diet type for final BW, ADG, TL, and SL. These traits were not influenced by salinity when it was associated with the AP diet, but reduced linearly with salinity in the P diet. DFI and survival rate were independently affected by salinity: DFI reduced linearly with salinity levels and survival rate was higher at a salinity of 10 g L-1. HSI increased linearly with salinity levels and was lower in the P diet than in the AP diet. Salinity had a quadratic effect on plasma TP, and the maximum value for this metabolite (2.96 g dL-1) is attained at a salinity of 10.26 g L-1. There was an independent effect of diet on the plasma concentrations of cholesterol and TG, which were lower in the P diet than in the AP diet. The salinity of 10 g L-1 associated with diet composed of animal and plant ingredients led to a better performance, higher survival rate, and less stressful environmental conditions for juvenile Nile tilapia.

Comparison of Gut Microbiota and Metabolic Status of Sows With Different Litter Sizes During Pregnancy

The experiment was conducted to compare the differences of gut microbiota and metabolic status of sows with different litter sizes on days 30 and 110 of gestation, and uncover the relationship between the composition of maternal gut microbiota during gestation and sow reproductive performance. Twenty-six Large White × Landrace crossbred multiparous sows (2nd parity) with similar back fat thickness and body weight were assigned to two groups [high-reproductive performance group (HP group) and low-reproductive performance group (LP group)] according to their litter sizes and fed a common gestation diet. Results showed that compared with LP sows, HP sows had significantly lower plasma levels of triglyceride (TG) on gestation d 30 (P < 0.05), but had significantly higher plasma levels of TG, non-esterified fatty acid, tumor necrosis factor-α, and immunoglobulin M on gestation d 110 (P < 0.05). Consistently, HP sows revealed increased alpha diversity and butyrate-producing genera, as well as fecal butyrate concentration, on gestation d 30; HP sows showed significantly different microbiota community structure with LP sows (P < 0.05) and had markedly higher abundance of Firmicutes (genera Christensenellaceae_R-7_group and Terrisporobacter) which were positively related with litter size on gestation d 110 than LP sows (P < 0.05). In addition, plasma biochemical parameters, plasma cytokines, and fecal microbiota shifted dramatically from gestation d 30 to d 110. Therefore, our findings demonstrated that microbial abundances and community structures differed significantly between sows with different litter sizes and gestation stages, which was associated with changes in plasma biochemical parameters, inflammatory factors, and immunoglobulin. Moreover, these findings revealed that there was a significant correlation between litter size and gut microbiota of sows, and provided a microbial perspective to improve sow reproductive performance in pig production.

Metabolism in calves two weeks before diarrhea at the age of 19-52 days of life

The article presents data on the study of metabolism in calves two weeks before diarrhea at the age of 19-52 days of life. For this purpose, three groups of conditionally healthy animals of the Holstein breed were formed at the age of 19, 30, 52 days of life. To assess the metabolic status of young cattle, biochemical and general clinical blood tests were carried out. In the course of a laboratory blood test in young cattle, two weeks before disease manifestation, disorders of mineral and protein metabolism, a decrease in liver function were established. At the same time, with the increase in the age of the calves, the imbalance in protein metabolism was aggravated against the background of a change in diet and mineral metabolism improved as a result of the maturation of the digestive system.