). In peripheral tissues, AMPK is phosphorylated and activated under elevated AMP levels by liver kinase B1 (LKB1; Sanders et al . 2007 ) following hormonal signals, such as adiponectin ( Yoon et al . 2006 ). Consequently, activated AMPK
Nava Chapnik, Yoni Genzer, Avraham Ben-Shimon, Masha Y Niv, and Oren Froy
Elena Grasselli, Adriana Voci, Ilaria Demori, Laura Canesi, Rita De Matteis, Fernando Goglia, Antonia Lanni, Gabriella Gallo, and Laura Vergani
Introduction Hepatic steatosis refers to an excess accumulation of lipids, primarily triglycerides (TAGs) and it is a major element of non-alcoholic fatty liver disease (NAFLD; Unger et al . 2010 ). Lipid metabolism is mainly regulated by the
Hamza Amine, Yacir Benomar, Adil Haimeur, Hafida Messaouri, Nadia Meskini, and Mohammed Taouis
, dietary fat plays an important role in the induction of insulin resistance ( Storlien et al . 1997 ). Both the amount and the type of fatty acids ingested alter insulin sensitivity in target tissues (i.e., muscle, adipose tissue and liver) associated with
G. C. KENNEDY, WINIFRED M. PEARCE, and DELPHINE M. V. PARROTT
During the 2nd and 3rd weeks of lactation the liver of the rat hypertrophied to approximately twice its normal size. There was a smaller, but significant, increase in the deoxyribonucleic acid (DNA) content, indicating an increase in cell number. The increase in liver protein was reversible, but that in DNA was not. These effects appeared to be due to changes in the intake of food.
A I Martín, M López-Menduiña, E Castillero, M Granado, M A Villanúa, and A López-Calderón
expression in the liver ( Defalque et al . 1999 , Priego et al . 2003 a ). The inhibitory effect of LPS can be exerted directly on the hepatocyte, since LPS is able to decrease Igf1 gene expression in hepatocyte cultures ( Priego et al . 2006 ). We have
1. Differential centrifugation, in 0·25 m sucrose solution, has been performed with rat liver and kidney tissue to ascertain whether the yield and composition of the cytoplasmic fractions (mitochondrial, microsome and supernatant fractions) depend on the hormonal status of the animal.
2. After hypophysectomy the ribonucleic acid (RNA) of the mitochondrial fraction from liver underwent a decrease (in terms of body weight) which was sufficient to account for the fall in the RNA of the liver as a whole. There was also a decrease in the yield of the mitochondrial fraction. Administration of pituitary growth hormone (GH) to hypophysectomized rats not only restored to normal the amount of RNA in the mitochondrial fraction and the yield of that fraction, but also led to an apparent shift of RNA from the microsome fraction to the supernatant fraction. A further change observed after hypophysectomy, whether or not GH had been given, was a rise in the yield of the microsome fraction. Hypophysectomized rats given thyrotrophin (TSH) did not show significant cytoplasmic changes as found with untreated hypophysectomized rats, but it was not possible to conclude that TSH had actually reversed the effects of hypophysectomy.
3. Castrated rats showed no abnormalities in the yields of the liver cytoplasmic fractions or in the concentration of RNA in the fractions. Alloxan-diabetic rats showed a rise in the yield of the supernatant fraction from liver.
4. Untreated adrenalectomized rats showed a rise in liver deoxyribonucleic acid, a fall in the yield of the liver mitochondrial fraction, but not in the amount of RNA in that fraction, and a rise in the amount of RNA in the supernatant fraction. Replacement therapy with various adrenocorticoids was attempted, with only partial success.
5. In contrast with the RNA content, the phospholipid content of the liver cytoplasmic fractions was not, in general, dependent on hormonal status.
6. Determinations of the yield and composition (RNA and phospholipid) of the cytoplasmic fractions from kidney disclosed certain hormonal effects, differing from those observed with liver; for example, the kidneys from hypophysectomized rats furnished microsome fractions in lowered yield but with an increased concentration of RNA.
M A Hyatt, G S Gopalakrishnan, J Bispham, S Gentili, I C McMillen, S M Rhind, M T Rae, C E Kyle, A N Brooks, C Jones, H Budge, D Walker, T Stephenson, and M E Symonds
Introduction Fetal hepatic growth is sensitive to maternal nutrient intake, particularly, during late gestation, when a reduction in food consumption can markedly compromise liver size at birth ( Bauer et al. 1995 ). This change in
J Svensson, M Diez, J Engel, C Wass, Å Tivesten, J-O Jansson, O Isaksson, T Archer, T Hökfelt, and C Ohlsson
serum IGF-I is liver derived ( Sjögren et al. 1999 , Yakar et al. 1999 ). The serum levels of IGF-I are mainly regulated by growth hormone (GH) ( Bengtsson et al. 1993 ), but are also affected by other factors, such as food intake, exercise and
Daniel E Francés, María T Ronco, Juan A Monti, Paola I Ingaramo, Gerardo B Pisani, Juan P Parody, José M Pellegrino, Paloma Martín Sanz, María C Carrillo, and Cristina E Carnovale
Introduction Diabetes is a common metabolic disorder in humans, which is associated with significant morbidity and mortality, and is a contributor to the development of other diseases. Indirectly or directly, the liver is a major target of insulin
Aijun Zhang, Douglas H Sieglaff, Jean Philippe York, Ji Ho Suh, Stephen D Ayers, Glenn E Winnier, Alexei Kharitonenkov, Christopher Pin, Pumin Zhang, Paul Webb, and Xuefeng Xia
Introduction Fibroblast growth factor 21 (FGF21) is one of three endocrine FGFs that influence metabolic responses via a combination of local and systemic actions. FGF21 is expressed in the liver, pancreas, and white and brown adipose tissue