Scandinavian Journal of Laboratory Animal Sciences 2018-03-06T14:09:45+02:00 Hanna-Marja Voipio Open Journal Systems <p>Published by the Scandinavian Society for Laboratory Animal Science, Sweden</p><p>Online ISSN <strong>2002-0112</strong></p> #1 Insulin dosing affects plasma levels of biochemical parameters in a time-dependent manner in Sprague-Dawley rats 2018-01-03T12:18:03+02:00 Vivi Flou Hjorth Jensen Stine Bartelt Anne-Marie Mølck Lene Andersen Søren Andersen Ingrid Brück Bøgh <p>Changes in levels of various biochemical blood parameters are used as indicators of metabolic effects or potential toxicity when performing non-clinical safety studies of new drug candidates in rats. Additionally, since biochemical blood parameters are often affected during safety testing of new insulin analogues the effect of insulin dosing on these parameters was investigated. Non-diabetic rats were dosed with either vehicle or insulin once daily for 28 days. On Day 28, biochemical blood parameters as well as insulin exposure were measured, at two hour intervals during a 24 h period, to investigate time-dependent as well as time-independent changes. Insulin dosing lowered plasma glucose level for 4 h, corresponding to the peak plasma insulin level. Chronic insulin dosing increased food consumption and bodyweights. Additionally, plasma urea as well as CK and LDH levels increased. Hyperphagia was most likely driven by hypoglycaemia thereby also increasing body weight through insulin-stimulated fatty acid uptake into adipose tissue. Increased urea, CK and LDH levels, suggests that the return to normoglycaemia was driven mainly by increased hepatic gluconeogenesis, as reflected by increased ureagenesis and skeletal muscle proteolysis (increased CK and LDH). A better understanding of insulin-induced changes to biochemical blood parameters may aid the interpretation of changes in these parameters in non-clinical safety studies with new drugs</p> 2018-01-03T00:00:00+02:00 ##submission.copyrightStatement## #2 PET radioligand injection for pig neuroimaging 2018-03-06T14:09:45+02:00 Aage KO Alstrup Ole L Munk Anne M Landau Thea P Lillethorup <p>Pigs are useful models in neuroimaging studies with positron emission tomography (PET). Radiolabeled ligands are injected intravenously at the start of the scan and in pigs the most easily accessible route of administration is the ear vein. However, in brain studies the short distance between the brain and ear vein can be problematic as both are localized inside the field of view and, as a consequence, tracer residues in the catheter may influence the outcome of the scan. Here, we discuss options to avoid this problem. The femoral vein can be used in studies where repeated arterial blood sampling is needed because surgical incision has to be performed to allow access to the artery. When a non-invasive technique is preferred, the ear vein is a good alternative although it is recommended to dilute the tracer sufficiently in saline (20-50 mL) prior to injection. In addition, the tracer can be injected through an extension tube (filled with saline before injection), which is removed together with the syringe immediately after tracer injection. This avoids placing the syringe with tracer inside the PET gantry while injecting. By applying these simple techniques, it is our experience that it is possible to obtain high-quality images without exposing pigs to invasive procedures.</p> 2018-03-06T00:00:00+02:00 ##submission.copyrightStatement##