Regulatory neuropeptides (ghrelin, obestatin and nesfatin-1) levels in serum and reproductive tissues of female and male rats with fructose-induced metabolic syndrome.
Although, the exact mechanisms underlying the development of the metabolic syndrome (MetS) are not still completely understood, obesity, circulated peptide hormone levels and their interaction with genetic factors are considered largely responsible. The purpose of this study is to explore how the levels of ghrelin, obestatin (OBS) and NUCB2/nesfatin-1 (NES)/NUCB2 change in serum and the reproductive tissues of female and male rats with fructose-induced metabolic syndrome, and whether the levels of each hormone is correlated with the hormones involved with fertility. Experiments were conducted on 5-week-old Sprague-Dawley male and female rats assigned to either a control group or a MetS group. Controls were fed standard rat food and water ad libitum, while the MetS group was fed standard food with 10% (v/v) fructose solution added to their drinking water for 12 weeks with a 12/12h photoperiod circle. Then, all animals were sacrificed after a one night fast. Peptides levels in the serum and reproductive tissues of rats were studied using the ELISA method while the immunoreactivity of reproductive system peptide hormones were shown by immunohistochemical staining method. Furthermore, the other biochemical parameters were measured using Konelab-60 equipment and infertility hormones were measured with Immulite2000. Fasting serum insulin, glucose, triglyceride, alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) levels were statistically significantly higher, and the amount of high density lipoprotein cholesterol (HDL-C) was significantly lower, in the MetS groups. Serum and tissue supernatant NES levels were significantly higher in the rats with MetS than the control group. Ghrelin, OBS and NES were expressed in the cytoplasm, concentrated around the apical parts of the epithelial cells in the reproductive tissues of the rats. The amounts of ghrelin were lower in the reproductive tissues of the animals with MetS, while NES levels in the same tissues increased. Obestatin also decreased, though not in the seminal glands.
Department of Medical Biochemistry and Clinical Biochemistry (Firat Hormones Research Group), Medical School, Firat University, 23119 Elazig, Turkey.
Zekiye
Z
Catak
Department of Medical Biochemistry and Clinical Biochemistry (Firat Hormones Research Group), Medical School, Firat University, 23119 Elazig, Turkey. Electronic address: saydin1@hotmail.com.
Suleyman
S
Aydin
Department of Medical Biochemistry and Clinical Biochemistry (Firat Hormones Research Group), Medical School, Firat University, 23119 Elazig, Turkey; Department of Histology and Embryology, Medical School, Erzincan University, 24030 Erzincan, Turkey.
Ibrahim
I
Sahin
Department of Histology and Embryology, Medical School, Firat University, 23119 Elazig, Turkey.
Tuncay
T
Kuloglu
Department of Medical Biochemistry and Clinical Biochemistry (Firat Hormones Research Group), Medical School, Firat University, 23119 Elazig, Turkey; Department of Nutrition and Dietetics, Bitlis Eren University, 13000 Bitlis, Turkey.
Aziz
A
Aksoy
Department of Medical Pathology, Medical School, Inonu University, 44280 Malatya, Turkey.
Adile Ferda
AF
Dagli
D000818:Animals; D002135:Calcium-Binding Proteins / Q000097:blood / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000097:blood / Q000378:metabolism*; D005260:Female; D005632:Fructose; D005835:Genitalia / Q000737:chemistry / Q000378:metabolism*; D054439:Ghrelin / Q000097:blood / Q000378:metabolism*; D008297:Male; D024821:Metabolic Syndrome / Q000139:chemically induced / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000097:blood / Q000378:metabolism*; D000080866:Nucleobindins; D036361:Peptide Hormones / Q000097:blood / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D054439:Ghrelin; D009419:Nerve Tissue Proteins; C000630652:Nucb1 protein, rat; D000080866:Nucleobindins; D036361:Peptide Hormones; C505798:obestatin, rat; D005632:Fructose
Ghrelin; Infertility; Metabolic syndrome; NUCB2/nesfatin-1; Obestatin