Title: The title of the abstract should emphasize the clinical condition and main teaching point.
Format: Abstract should be a clear and concise summary of the major aspects of your research, including:
Introduction or background
Hypothesis and underlying questions the research addresses
Overview of experimental design and methodology
Interpretation of results and conclusions
Disclosures of potential conflicts of interest and sources of support as applicable
Abstract submissions are text only, limited to 2,500 characters (excluding spaces).
No figures or tables may be submitted.
Use past tense when writing a scientific abstract.
Abbreviations: Abbreviations that are familiar to endocrinologists may be used without explanation, e.g. PCR, GHRH, TSH.
Laboratory values: For laboratory parameters, the units of measurement and normal ranges must be provided.
Statements about ongoing studies or pending results should be avoided.
References are not necessary and should be kept to a minimum.
Example of Outstanding Scientific Abstract
Brain Insulin Signaling Increases Hepatic Triglyceride Secretion In Vivo
Thomas Scherer, MD1,2, Claudia Lindtner, MD1, James O'Hare, BS1, Liz Zielinski, BS1, Ludger Scheja, PhD3 and Christoph Buettner, MD, PhD1
1Dept of Med, Mount Sinai Schl of Med New York, NY 2Dept of Med III, Med Univ of Vienna Vienna, Austria 3Dept of Biochem and Mol Biol II, Univ Med Ctr Hamburg, Germany
Abstract: Hepatosteatosis and dyslipidemia are hallmarks of the metabolic syndrome and plasma triglycerides (TG) tightly correlate with insulin resistance (IR). Since hepatic lipogenesis is increased in the IR state, TG secretion must not be too low to prevent steatosis. Insulin action comprises direct effects on peripheral organs e.g. liver and adipose, and indirect effects mediated via the central nervous system (1). Systemic insulin decreases very low-density lipoprotein (VLDL) production by the liver, yet it is unknown if brain insulin can independently regulate VLDL flux. To study the role of brain vs. systemic insulin signaling on hepatic VLDL secretion, we performed tyloxapol infusion studies in male Sprague Dawley rats during systemic or isolated brain hyperinsulinemia. The latter was accomplished by infusing insulin or vehicle for 4 hrs into the 3rd ventricle (ICV) or the mediobasal hypothalamus (MBH). ICV insulin infusion increased hepatic VLDL secretion compared to controls (2.59±0.28 vs. 1.80±0.2 μmol/kg/min; P=0.039; n 11 per group). To the contrary, a hyperinsulinemic euglycemic clamp decreased TG flux (0.85±0.05 μmol/kg/min; P=0.020; n=4), which is in agreement with prior reports (2). Plasma lipid profiling in these rats demonstrated that ICV insulin increased the accumulation of TG associated fatty acids such as palmitate or oleate (+30%; P<0.05). Of note, insulin infusion into the MBH had no effect on VLDL flux vs. controls (1.85±0.32 μmol/kg/min vs. 1.71±0.32 μmol/kg/min; P=0.773; n=5 per group) indicating that another brain region integrates the central insulin-signal. Conversely, mice lacking insulin receptor in the whole brain had reduced hepatic TG flux compared to littermate controls, which was again assessed by tyloxapol studies (154±6 vs. 126±12 μmol/kg/h; P = 0.038; n 9 per group). To begin to understand the molecular underpinnings that alter hepatic VLDL flux when ICV insulin is infused, we assessed hepatic microsomal TG transfer protein (MTTP) expression, the rate-limiting enzyme in VLDL assembly. Consistent with VLDL flux, ICV insulin increased MTTP expression compared to controls (P=0.046; n 5). While systemic hyperinsulinemia and isolated loss of neuronal insulin signaling both suppress TG flux, ICV insulin infusion acutely increases VLDL secretion. We speculate that the elevated TG production in obesity and diabetes may be due to preserved central insulin effects in a presently unknown brain region.
Reference: (1) Scherer et al., Cell Metab. 2011 Feb 2;13(2):183-94. (2) Grefhorst et al., Am J Physiol Gastrointest Liver Physiol. 2005 Sep;289(3):G592-8.
Nothing to Disclose: TS, CL, JO, LZ, LS, CB
Sources of Research Support: NIH Grants DK074873, DK083568 and DK082724 awarded to CB; ADA basic research award to CB; European Foundation for the Study of Diabetes Grant awarded to TS; CB is the recipient of a Hirschl Award.