Obesity Induces Hypothalamic Endoplasmic Reticulum Stress and Impairs Proopiomelanocortin (POMC) Post-translational Processing

It was shown previously that abnormal prohormone processing or inactive proconverting enzymes that are responsible for this processing cause profound obesity. Our laboratory demonstrated earlier that in the diet-induced obesity (DIO) state, the appetite-suppressing neuropeptide -melanocyte-stimulating hormone ( -MSH) is reduced, yet the mRNA of its precursor protein proopiomelanocortin (POMC) remained unaltered. It was also shown that the DIO condition promotes the development of endoplasmic reticulum (ER) stress and leptin resistance. In the current study, using an in vivo model combined with in vitro experiments, we demonstrate that obesity-induced ER stress obstructs the post-translational processing of POMC by decreasing proconverting enzyme 2, which catalyzes the conversion of adrenocorticotropin to -MSH, thereby decreasing -MSH peptide production. This novel mechanism of ER stress affecting POMC processing in DIO highlights the importance of ER stress in regulating central energy balance in obesity.Fil: Cakir, Isin. Brown University; Estados UnidosFil: Cyr, Nicole E.. Brown University; Estados UnidosFil: Perello, Mario. Brown University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Litvinov, Bogdan Patedakis. Brown University; Estados UnidosFil: Romero, Amparo. Brown University; Estados UnidosFil: Stuart, Ronald C.. Brown University; Estados UnidosFil: Nillni, Eduardo A.. Brown University; Estados Unido

Hadronic vacuum polarization correction to atomic energy levels

The shift of atomic energy levels due to hadronic vacuum polarization is evaluated in a semiempirical way for hydrogenlike ions and for muonic hydrogen. A parametric hadronic polarization function obtained from experimental crosssections of e- e+ annihilation into hadrons is applied to derive an effective relativistic Uehling potential. The energy corrections originating from hadronic vacuum polarization are calculated for low-lying levels using analytical Dirac-Coulomb wave functions, as well as bound wave functions accounting for the finite nuclear size. Closed formulas for the hadronic Uehling potential of an extended nucleus as well as for the relativistic energy shift in case of a point-like nucleus are derived. These results are compared to existing analytic formulas from non-relativistic theory

Short communicationi: Shelled acorn seed (Quercus cerris) as a diet ingredient onthe performance of growing Japanese Quail

This study was carried out to investigate the effects of dietary inclusion of shelled acorn seed (Quercus cerris) on the growth performance and carcass yield of Japanese quail (Coturnix coturnix japonica). Four hundred four-day old quail chicks were used in this study. Experimental diets contained 0, 5, 10, 15 or 20% shelled acorn seed. The experiment lasted 38 days. There were no differences between treatments in body weight, body weight gain, feed intake and feed conversion ratio. Furthermore, the mortality rate and carcass yield were not affected by the inclusion in the diet of different levels of shelled acorn seed. The inclusion of shelled acorn seed to the quail diets did not cause any harmful effect on the health of the birds. These results suggested that up to 20% shelled acorn seed could be included as an energy source in quail diets. Keywords: Acorn seed, Coturnix coturnix japonica, growth performanceSouth African Journal of Animal Science Vol. 38 (1) 2008: pp. 38-4