Effects of apelin on reproductive functions: relationship with feeding behavior and energy metabolism

Abstract

Apelin is an adipose tissue derived peptidergic hormone. In this study, 40 male Sprague-Dawley rats were used (four groups; n = 10). Apelin-13 at three different dosages (1, 5 and 50 μg/kg) was given intraperitoneally while the control group received vehicle the same route for a period of 14 days. In results, apelin-13 caused significant decreases in serum testosterone, luteinizing hormone and follicle-stimulating hormone levels (p < 0.05). Administration of apelin-13 significantly increased body weights, food intake, serum low-density lipoprotein and total cholesterol levels (p < 0.05), but caused significant decreases in high-density lipoprotein levels (p < 0.05). Serum glucose and triglyceride levels were not significantly altered by apelin-13 administration. Significant decreases in both uncoupling protein (UCP)-1 levels in the white and brown adipose tissues and UCP-3 levels in the biceps muscle (p < 0.05) were noted. The findings of the study suggest that apelin-13 may not only lead to obesity by increasing body weight but also cause infertility by suppressing reproductive hormones.

Apelin-13 increased food intake with serum ghrelin and leptin levels in male rats

“…Nonetheless, different results were obtained in the studies reporting that apelin suppressed (11,12), increased (13,14,15) or did not change food intake (6). These results show that the role of apelin in the regulation of feeding behavior is not clear yet.…”

“…Valle et al (13) showed that chronic central administration of apelin-13 ıncreased body weight, locomotor activity and body temperature in C57BL/6 mice. Tekin et al (14) reported that chronic apelin-13 increased rats food intake and body weight, and the study showed the orexigenic effect of apelin-13.…”

Apelin and apj in common carp ( Cyprinus carpio L.): Molecular characterization, tissue expression and responses to periprandial changes and fasting–refeeding

“…Apelin was first reported in 1998 (Tatemoto et al, 1998); the functions of apelin and its receptor were well investigated in mammals. As an adipokine, the studies of apelin and its receptor were mainly focused on energy metabolism (Gourdy et al, 2018;Tekin et al, 2017), cardiac contractility (Gerbier et al, 2017;Gunter et al, 2017;Ni et al, 2017), apoptosis or inflammation (Han et al, 2017;Hoffmann et al, 2017). To clarify the functional roles of apelin/apj in teleost, firstly, we isolated and characterized the apelin and apjs genes from the common carp.…”

“…The apelin/apj system plays important and various roles in the physiology and pathophysiology of many organs, including the regulation of blood pressure (Chen et al, 2003), cardiac contractility (Gerbier et al, 2017;Gunter et al, 2017;Ni, Liu, Ge, Zhu, & Zhang, 2017), angiogenesis (Masri, Morin, Cornu, Knibiehler, & Audigier, 2004), metabolic balance (Gourdy et al, 2018;Tekin et al, 2017) and cell proliferation (Kleinz & Davenport, 2005), apoptosis or inflammation (Han, Englander, Gomez, & Greeley, 2017;Hoffmann, Fiedor, & Ptak, 2017).…”

The Role of Apelin in the Functioning of the Reproductive System

“…Основываясь на этих результатах, авторы сделали вывод о негативной регуляции апелином-13 ГГГ оси у самцов крыс, но без существенного влияния на гистологическую структуру семенников и процесс сперматогенеза [48]. В дальнейшем той же группой было изучено внутрибрюшинное введение самцам крыс Wistar-Albino апелина-13 в суточных дозах 1, 5 и 50 мкг/кг в течение 14 дней [49]. Такая обработка статистически значимо снижала уровни тестостерона и ЛГ, приводила к повышению массы тела, гиперфагии, повышала уровни атерогенного холестерина и индекс атерогенности.…”