Effect of Fasting on the Spexin System in Broiler Chickens

Spexin (SPX) is a highly conservative peptide hormone containing 14 amino acids and was discovered in 2007 by bioinformatics methods. However, nothing is yet known about its role in the metabolism of birds, including broilers. The aim of this study was to investigate the effect of short-term fasting (2, 4, and 8 h) on the concentration of SPX in blood serum and the expression levels of the genes encoding this peptide (SPX1) and its receptors, GALR2 and GALR3, in the tissues involved in carbohydrate and lipid metabolism (muscles, adipose tissue, and liver). We also analyzed the mRNA expression of these genes in various chicken tissues. Moreover, we studied the correlation between the serum level of SPX and other metabolic parameters (insulin, glucagon, glucose, triglycerides, and cholesterol). Using RT-qPCR, we found that SPX1, GALR2, and GALR3 are expressed in all investigated tissues in broiler chicken. Moreover, using a commercially available radio-immunoassay, we noted an increase of the SPX level in blood serum after 4 and 8 h of fasting compared to nonfasted animals (p < 0.05). This increase was positively correlated with glucagon concentration (r = 0.341; p < 0.05) and negatively with glucose concentration (r = −0.484; p < 0.01). Additionally, we discovered that in the short term, food deprivation leads to the expression regulation of SPX1, GALR2, and GLAR3 in tissues associated with metabolism of carbohydrates and lipids. The obtained results indicate that SPX is involved in the regulation of metabolism in broiler chickens.

Excipient Interactions in Glucagon Dry Powder Inhaler Formulation for Pulmonary Delivery

Purpose: This study describes the development and characterization of glucagon dry powder inhaler (DPI) formulation for pulmonary delivery. Lactose monohydrate, as a carrier, and L-leucine and magnesium stearate (MgSt) were used as dispersibility enhancers for this formulation. Methods: Using Fourier-transform infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), and Raman confocal microscopy, the interactions between glucagon and all excipients were characterized. The fine particle fractions (FPFs) of glucagon in different formulations were determined by a twin stage impinger (TSI) using a 2.5% glucagon mixture, and the glucagon concentration was measured by a validated LC-MS/MS method. Results: The FPF of the glucagon was 6.4%, which increased six-fold from the formulations with excipients. The highest FPF (36%) was observed for the formulation containing MgSt and large carrier lactose. The FTIR, Raman, and DSC data showed remarkable physical interactions of glucagon with leucine and a minor interaction with lactose; however, there were no interactions with MgSt alone or mixed with lactose. Conclusion: Due to the interaction between L-leucine and glucagon, leucine was not a suitable excipient for glucagon formulation. In contrast, the use of lactose and MgSt could be considered to prepare an efficient DPI formulation for the pulmonary delivery of glucagon.

PO-066 The Function of t Lycium Barbarum Juice Supplemen in Exercise Stress Regulation during Increasing Resistance Training

Objective The purpose of this study was to explore the function of Lycium Barbarum juice on exercise stress regulation when male university students drank Lycium Barbarum juice during increasing resistance exercise, by observing the effects of oral Lycium Barbarum juice on the blood glucose, serum Adrenocorticotropic Hormone (ACTH), insulin and glucagon concentration. Methods 21 to 22, healthy, 28 male university students participated in the study. They were randomly divided into a control group (n=16)and an experimental group(n=12). All participants completed four-stage incremental load movement for a total of 32 days. The exercise intensity of four stages was 60% VO2max, 70% VO2max, 80% VO2max and 90% VO2max, respectively. Each stage was exercised every-other-day, 4 times per stage and 1 hour each time. During the exercise, each subject in the experimental group drank 100 ml of 100% Lycium Barbarum juice before going to bed every day. Before the experiment and the morning after the end of each phase, a participant’s elbow-venous blood was collected to separate the serum. In all serum substances, the concentrations of ACTH, insulin, glucagon were detected by ELISA system. Fasting blood glucose concentration was detected by a blood glucose meter (Kyoto GT-1640 glucose meter, Japan). SPSS 17.0 software was used for statistical analysis. Results 1) The serum ACTH concentration of the subjects continually increased with the progress of the incremental load exercise and reached the highest at the end of the fourth stage. Compared with the increase in the control group (P<0.05), the experimental group was more significant (P<0.01). 2) Compared with before the experiment, both control group and experimental group were no obvious changes of blood glucose concentration in the first and second stages, and the control group was significantly decreased in the third and fourth stages (P<0.05), while the experimental group was not (P>0.05). 3) During the increasing load exercise, the changes of insulin in serum of the participants were basically the same. The insulin level increased significantly at the end of the first stage and decreased successively at the end of the last three stages. At the end of the fourth stage, the serum insulin level of the control group decreased more significantly (P<0.05) than the experimental group (P>0.05). 4) The glucagon concentration in the control group continued to increase with the increase of the load. By contrast, the glucagon concentration in the experimental group gradually decreased at the end of the first stage and then increased at the end of the fourth stage. However, all of the increase and decrease are not statistically significant. Conclusions During increasing resistance exercise, drinking Lycium Barbarum juice can increase the ability of the body to regulate Adrenocorticotropic Hormone (ACTH), insulin and glucagon through the exercise stress regulation systems, the Hypothalamic-Pituitary-Adrenal Cortical Hormone system (HPA) and the Sympathetic-Adrenal Medullary system. It plays an important role in maintaining blood sugar levels during increasing resistance exercise and accelerating post-exercise function recovery after exercise.

Interaction of Ingested Leucine with Glycine on Insulin and Glucose Concentrations

The majority of individual amino acids increase insulin and attenuate the plasma glucose response when ingested with glucose. Objective. To determine whether ingestion of two amino acids simultaneously, with glucose, would result in an additive effect. Leucine (Leu) and glycine (Gly) were chosen because they were two of the most potent glucose-lowering amino acids when given individually. Materials and Methods. Nine subjects received test items on four separate days. The first was a water control, then 25 g glucose, or Leu + Gly (1 mmol/kg fat-free mass each) ±25 g glucose, in random order. Glucose, insulin, and glucagon were measured frequently for 2.5 hours. Net areas were calculated. Results. The glucose area response decreased by 66%. The insulin area response increased by 24% after ingestion of Leu + Gly + glucose compared to ingestion of glucose alone. The decrease in glucose response was not additive; the increase in insulin response was far less than additive when compared to previously published individual amino acid results. The glucagon concentration remained unchanged. Conclusion. There is an interaction between Leu and Gly that results in a markedly attenuated glucose response. This occurred with a very modest increase in insulin response. Changes in glucagon response could not explain the results. The mechanism is unknown.