title: Diet-Induced Obesity and Ghrelin Effects on Pituitary Gonadotrophs: Immunohistomorphometric Study in Male Rats.
abstract: OBJECTIVE
  The close relationship between energy metabolism, nutritional state, and reproductive physiology suggests that nutritional and metabolic disorders can disrupt normal reproductive function and fertility. Considering the importance of leptin and ghrelin effects in regulation of the hypothalamic-pituitary-gonadal axis, the objective of this study was to investigate the influence of obesity and centrally applied ghrelin on immunohistochemical appearance and quantitative morphology of the pituitary follicle-stimulating hormone (FSH) and luteinizing hormone (LH) producing cells in adult male rats.
  
  
  METHODS
  In this experimental study, animals were given two differ- ent diets: normal-fat (NF) and high-fat (HF), for 4 weeks, corresponding to normal and positive energy balance (n=2×14), respectively. Each group was subsequently divided into two subgroups (n=7) receiving intracerebroventricular (ICV) injections of either ghrelin [G, 1 µg/5 µL phosphate buffered saline (PBS)] or vehicle (5 µL PBS, control group) every 24 hours for five consecutive days.
  
  
  RESULTS
  Morphometric analyses showed that in HF control group, the percentage of FSH cells per unit volume of total pituitary gland tissue (in μm(3)), i.e. volume density (Vvc), was increased (P<0.05) by 9.1% in comparison with the NF controls. After ICV treatment with ghrelin, volume (Vc) and volume density (Vvc) of FSH cells in ghrelin+NF (GNF) and ghrelin+HF (GHF) groups remained unchanged in comparison with NF and HF controls. Volume of LH cells in HF control group was increased by 17% (P<0.05), but their Vvc was decreased by 8.3% (P<0.05) in comparison with NF controls. In GNF group, the volume of LH cells increased by 7% (P<0.05), in comparison with the NF controls, but in GHF group, the same parameter remained unchanged when compared with HF controls. The central application of ghrelin de- creased the Vvc of LH cells only in GNF group by 38.9% (P<0.05) in comparison with the NF control animals.
  
  
  CONCLUSIONS
  The present study has shown that obesity and repetitive ICV administra- tion of low doses of ghrelin, in NF and HF rats, modulated the immunohistomorphometric features of gonadotrophs, indicating the importance of obesity and ghrelin in regulation of the reproductive function.
authors: Institute for Biological Research Sinisa Stankovic, University of Belgrade, Belgrade, Serbia.
authors: Natasa
authors: N
authors: Ristic
authors: Institute of Medical Physiology, School of Medicine, University of Belgrade, Belgrade, Serbia.
authors: Darko
authors: D
authors: Stevanovic
authors: Institute of Medical Physiology, School of Medicine, University of Belgrade, Belgrade, Serbia.
authors: Dejan
authors: D
authors: Nesic
authors: Institute for Biological Research Sinisa Stankovic, University of Belgrade, Belgrade, Serbia.
authors: Vladimir
authors: V
authors: Ajdzanovic
authors: Institute of Medical Physiology, School of Medicine, University of Belgrade, Belgrade, Serbia.
authors: Rastko
authors: R
authors: Rakocevic
authors: Institute for Biological Research Sinisa Stankovic, University of Belgrade, Belgrade, Serbia.
authors: Ivana
authors: I
authors: Jaric
authors: Institute for Biological Research Sinisa Stankovic, University of Belgrade, Belgrade, Serbia.
authors: Verica
authors: V
authors: Milosevic
keywords: Ghrelin; Gonadotrophs; Male; Obesity; Rats