title: Changes of growth hormone-releasing hormone and somatostatin neurons in the rat hypothalamus induced by genistein: a stereological study.
abstract: OBJECTIVE
  Genistein is a plant-derived estrogenic isoflavone commonly found in dietary and therapeutic supplements, due to its potential health benefits. Growth hormone-releasing hormone (GHRH) and somatostatin (SS) are neurosecretory peptides synthesized in neurons of the hypothalamus and regulate the growth hormone secretion. Early reports indicate that estrogens have highly involved in the regulation of GHRH and SS secretions. Since little is known about the potential effects of genistein on GHRH and SS neurons, we exposed rats to genistein.
  
  
  METHODS
  Genistein were administered to adult rats in dose of 30 mg/kg, for 3 weeks. The estradiol-dipropionate treatment was used as the adequate controls to genistein. Using applied stereology on histological sections of hypothalamus, we obtained the quantitative information on arcuate (Arc) and periventricular (Pe) nucleus volume and volume density of GHRH neurons and SS neurons. Image analyses were used to obtain GHRH and SS contents in the median eminence (ME).
  
  
  RESULTS
  Administration of estradiol-dipropionate caused the increase of Arc and Pe nucleus volume, SS neuron volume density, GHRH and SS staining intensity in the ME, when compared with control. Genistein treatment increased: Arc nucleus volume and the volume density of GHRH neurons (by 26%) and SS neurons (1.5 fold), accompanied by higher GHRH and SS staining intensity in the ME, when compared to the orhidectomized group.
  
  
  CONCLUSIONS
  These results suggest that genistein has a significant effect on hypothalamic region, involved in the regulation of somatotropic system function, and could contribute to the understanding of genistein as substance that alter the hormonal balance.
authors.affiliation: a Department of Cytology , Institute for Biological Research 'Siniša Stanković', University of Belgrade , Belgrade , Serbia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Trifunović
authors.affiliation: a Department of Cytology , Institute for Biological Research 'Siniša Stanković', University of Belgrade , Belgrade , Serbia.
authors.forename: Milica
authors.initials: M
authors.lastname: Manojlović-Stojanoski
authors.affiliation: a Department of Cytology , Institute for Biological Research 'Siniša Stanković', University of Belgrade , Belgrade , Serbia.
authors.forename: Nataša
authors.initials: N
authors.lastname: Ristić
authors.affiliation: a Department of Cytology , Institute for Biological Research 'Siniša Stanković', University of Belgrade , Belgrade , Serbia.
authors.forename: Nataša
authors.initials: N
authors.lastname: Nestorović
authors.affiliation: a Department of Cytology , Institute for Biological Research 'Siniša Stanković', University of Belgrade , Belgrade , Serbia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Medigović
authors.affiliation: a Department of Cytology , Institute for Biological Research 'Siniša Stanković', University of Belgrade , Belgrade , Serbia.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Živanović
authors.affiliation: a Department of Cytology , Institute for Biological Research 'Siniša Stanković', University of Belgrade , Belgrade , Serbia.
authors.forename: Verica
authors.initials: V
authors.lastname: Milošević
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D048429:Cell Size / Q000187:drug effects; D019587:Dietary Supplements / Q000009:adverse effects; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000494:pharmacology; D004967:Estrogens / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D019833:Genistein / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D013007:Growth Hormone-Releasing Hormone / Q000819:agonists* / Q000378:metabolism; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D007279:Injections, Subcutaneous; D008297:Male; D008473:Median Eminence / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D055495:Neurogenesis / Q000187:drug effects*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D048789:Phytoestrogens / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D017208:Rats, Wistar; D013004:Somatostatin / Q000819:agonists* / Q000378:metabolism; D013238:Stereotaxic Techniques
chemical_list: D004967:Estrogens; D048789:Phytoestrogens; D004958:Estradiol; D013004:Somatostatin; D013007:Growth Hormone-Releasing Hormone; D019833:Genistein; C023482:estradiol dipropionate
keywords: GHRH; Genistein; Histology; SS; Stereology