Endocrine Abstracts

The arcuate nucleus of the hypothalamus (ARH) is localized within lateral walls of the third ventricle above the median eminence. From the functional point of view ARH takes part in the regulation of food intake, energy expenditure and body weight. The aim of this study was to investigate the influence of food deprivation on ultrastructural alterations of the rough endoplasmic reticulum (RER)/Golgi network in the arcuate neurons of young rats. There have been no reports describing the effect of food deprivation on the formation of membranous whorls, the function of which is still unclear. Otherwise, under different stress conditions like morphine, colchicine or mercury treatment, the arcuate neurons exhibited those structures. Inbred male rats aged 5 months were divided into three groups (4 in each group): control (normally fed), and deprived of food for 48 hrs and 96 h. Simultaneously, total 8-isoprostane serum level was assayed as a marker of oxidative stress inducing lipid peroxidation in vivo. In both groups of food deprived animals we observed rearrangements of the RER in the form of lamellar bodies and membranous whorls. The lamellar bodies in controls were rather short and dispersed in the neuronal cytoplasm. Whereas, in food deprived animals they became longer and participated in the formation of membranous whorls composed of concentric layers of endoplasmic reticulum. The membranous whorls were often placed in the vicinity of very well developed Golgi complexes. Some Golgi complexes displayed an early stage of whorls formation. This observation correlates with a significant increase in serum 8-isoprostane levels in food deprived animals as compared to the fed control.