Effect of food manipulation on the neuropeptide Y neuronal system in the diencephalon of ewes.
The expression of neuropeptide Y (NPY), which is involved in the neuromodulatory function associated with animal nutrition, growth and reproduction, depends on the nutritional status. However, the roles of individual components of food are not fully recognised. In this study, we evaluated the effects of dietary protein levels on the diencephalic population of NPY neurones. Female lambs were fed two diets equilibrated energetically but containing 8% protein in restricted diet or 18% protein in elevated diet, for 15 weeks starting with 6 months of age, during the first breeding period. Then, brain tissues were collected, fixed and used for the immunohistochemical localisation of NPY. Detection of NPY in diencephalon sections was followed by the image analysis and expressed as the percent area stained and optical density of immunostaining. Two distinct populations of the immunoreactive NPY perikarya were found, one in the infundibular nucleus; and the other in areas of diencephalon adjacent to the rostral hypothalamus. Long-term feeding the protein restricted diet caused a prominent expression of the immunoreactive material solely in the hypothalamic NPY neurones, particularly in those located in the entire periventricular area and in the infundibular nucleus. Both, percent area exhibiting positive staining and the density of immunoreactive NPY measured in the periventricular subdivision of the paraventricular nucleus were significantly higher (P<0.05) in sheep fed restricted diet, than in sheep fed on elevated diet. This study describes the distribution of NPY neurones in the sheep diencephalon, and shows the relationships between the expression of hypothalamic population of NPY neurones and the level of protein feeding.
Polkowska
J
J
The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110, Jablonna, Poland. j.polkowska@if22.pan.pl
Gładysz
A
A
D000818:Animals; D001835:Body Weight / Q000502:physiology; D004027:Diencephalon / Q000033:anatomy & histology / Q000166:cytology / Q000378:metabolism*; D004032:Diet; D004044:Dietary Proteins / Q000494:pharmacology; D005260:Female; D007031:Hypothalamus / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism*; D009478:Neuropeptide Y / Q000096:biosynthesis*; D012756:Sheep
D004044:Dietary Proteins; D009478:Neuropeptide Y