Sıçanlarda Akut Koşu Egzersizinin Dolaşım ve Periferal Dokularda Speksin Düzeyine Etkisi

Abstract

Bioactive molecules, known as exerkines, which are synthesized in different tissues in response to acute and chronic exercise and released into circulation, are thought to play a critical role in improving obesity, diabetes, metabolic syndrome, cancer, and neurological health through endocrine, paracrine, and autocrine actions. One of the candidate molecules for exerkines is spexin, which plays an active role in regulating body weight, energy balance, and glucose and lipid metabolism, as well as central effects such as appetite and food intake control. This study aimed to investigate changes in spexin levels in response to acute running exercise in rats. Forty-two male Sprague Dawley rats were divided into seven groups (n = 6 per group): 1) sedantary (SED), 2) immediately after acute exercise (0), 3) 1h post-exercise (1), 4) 3h post-exercise (3), 5) 6h post-exercise (6), 6) 12h post- exercise (12), and 7) 24h post-exercise (24). Animals in the exercise groups underwent a 60-minute acute exercise protocol at 25 m/min on a 0% grade. Upon completing the experimental protocol, soleus (SOL) and extensor digitorum longus (EDL) muscles, adipose tissue, liver, and plasma samples were collected from each animal. Plasma spexin levels were analyzed using the ELISA method, and the gene expression levels of spexin and galanin receptor 2 (GALR2) in tissues were assessed through real-time PCR. Additionally, spexin staining in tissues was examined using the immunohistochemistry method. Statistical analysis was performed using one-way analysis of variance (ANOVA), and the Least Significant Difference (LSD) post hoc test was applied for pairwise comparisons. Plasma spexin levels significantly increased 1h after acute running exercise (p<0.05) compared to the SED and returned to baseline levels at 6, 12, and 24h post- exercise. Acute exercise also elevated spexin mRNA levels in the SOL and EDL muscles, as well as in the liver, in a time-dependent manner (p<0.05) compared to the SED, whereas no significant changes were observed in adipose tissue (p>0.05). In addition, GALR2 mRNA levels, the target receptor of spexin, were significantly decreased in the SOL and liver (p<0.05) compared to the SED but remained unchanged in the EDL and adipose tissue (p>0.05). Immunohistochemistry results further revealed that spexin staining decreased in the liver following acute exercise but remained unchanged in the SOL muscle, with no spexin staining detected in the EDL and adipose tissue. These findings indicate that there is a time-dependent increase in spexin levels with acute exercise, implying that some of the health benefits of exercise may be mediated by spexin. We believe that our findings will add to the growing body of evidence that spexin has the potential to be an exerkine.