169-175
Intestinal permeability and
faecal Granulocyte Marker Protein in Dextran Sulphate Sodium - induced
colitis in rats
by Anne Marita Milde, Gülen Arslan, Arne Røseth, Arnold Berstad,
J. Bruce Overmier & Robert Murison
The aims of this preliminary study were to foster the development of an animal model of inflammatory bowel disease (IBD). We hereby studied the effects of dextran sulphate sodium (DSS) in drinking water on (a) intestinal permeability and (b) faecal levels of granulocyte marker protein (GMP) in rats. Methods were adopted to keep stress at a minimum. The animals had free access to DSS for 36 or 96 hrs. Controls received only water. Oral administration of 51Cr-labelled ethylenediaminetetraacetic acid (51CrEDTA) is used for clinical evaluation of intestinal permeability in IBD. 51CrEDTA was administered by training the animals to drink a given quantity of fluid within 5 minutes in a specific environment. On the test day, they voluntarily consumed 1 ml water containing 2 µCi 51CrEDTA. Urine samples were taken from filter paper in their home-cages for 6 hrs and radioactivity measured in a gamma counter. Faecal samples were collected after 36 and 96 hrs on DSS or water for GMP analysis. RESULTS: GMP was elevated in the DSSinduced animals after both 36 hrs (p<.05) and 96 hrs (p<.01), the elevation being greater after 96 hrs. Consumption of DSS increased the urinary excretion of 51CrEDTA after 36 hrs, but not after 96 hrs. Only DSS consumption for 96 hrs resulted in visible colonic erosions in either the proximal, mid or distal part of the colon. CONCLUSION: DSS has an acute effect upon urinary excretion of 51CrEDTA, and 96 hrs of access to DSS is sufficient to induce elevated GMP levels and colonic erosions in adult rats.
177-190
Postprandial
hyperlipemia in pigs
by Jakob Harslund, Aage Kristian Olsen& Axel Kornerup Hansen
The ability to induce postprandial hyperlipemia is essential for using certain animal species as models for short-term consequences of fat intake in humans. We present the results from two studies on postprandial hyperlipemia and triglyceride metabolism in young slaughter pigs using the proprietary lipid-containing product, Intralipid®. In the first study we demonstrated that postprandial hyperlipemia in slaughter pigs was insignificant (p=0.16) when fed Intralipid® in doses of 2 g fat/kg administered in two fractions: the first 1/3 11/2 hours after feeding, and the second 2/3 11/2 hours later. In the second study, induction of postprandial hyperlipemia was performed by administering Intralipid® in single doses of 2 g fat/kg 51/2 hours after feeding, which resulted in the development of significant postprandial hyperlipemia (p<0.001). To assess the half-life (T1/2) of triglycerides in the circulation, Intralipid® was administered intravenously in doses of 0.1 g fat/kg, which gave T1/2 (mean ± std.)=13.3±3.7 minutes. Furthermore, inhibiting the lipoprotein lipase by administering Triton WR-1339 intravenously in doses of 150 mg/kg exerted a significant inhibitory effect on the triglyceride catabolism in the circulation as determined by increments in peak value (p<0.05), increased area under the curve (iAUC) (p<0.01), and T1/2 (p<0.05). In conclusion, the slaughter pigs developed significant postprandial hyperlipemia when fed Intralipid® in doses of 2 g fat/kg 51/2 hours after feeding, while it was difficult to induce significant postprandial hyperlipemia when the same amount of fat was administered in two fractions in close proximity to feeding. We hypothesize that the high activity of the endothelial lipases, determined by the T1/2, constitutes the physiological threshold counteracting the development of postprandial hyperlipemia in young slaughter pigs.
197-201
Short-term effects of storage time
and temperature on pH, pCO2, and pO2 in porcine arterial blood
by Aage Kristian Olsen
There is evidence that pre-analytical handling may be an important determinant of blood gas variables. To study this possibility we investigated the influence of storage time (5, 15, 30, 45, and 60 minutes after blood sampling) and storage temperature (4oC and 20oC) on the variation in pH, pCO2, and pO2 in porcine blood. We found that the median pH decreased (P<0.001), but did not exhibit clinically significant changes. The median pCO2 increased with duration of storage (P<0.001) and the median pO2 was variable at 4oC (P=0.002), and decreased at 20oC (P<0.001). The variations in pCO2 and pO2 were higher at 20oC than at 4oC. This study demonstrates that time delay before analysis of blood gas can be a cause of increased variation, and should be minimised in order to avoid false results and to ensure correct conclusions. If a delay of more than five minutes in analysis is expected, the specimen should be placed on crushed ice.
209-215
The autonomic innervation of the
testicular parenchyma: a rat model
by Ender Erdogan, Atýf Aydinlioglu, Murat Ç. Ragbetli,
Hanefi Özbek& Fatma Göçer
The specific roles and direct involvements of autonomic innervations on the spermatogenic process are poorly understood. The aim of this study was to investigate stereologically the relative importance of sympathetic innervations in testicular parenchyma rats in chemically sympathectomized with guanethidine. Treated animals (n=10) were injected intraperitoneally with guanethidine at doses of 10mg/kg/day for 15 days while control animals (n= 5) received an equivalent volume of saline. After routine histological procedures, 5µm thick sections of the testes were selected for examination. Organ volumes were estimated using the Cavalieri Principle of volume measurement by means of consecutive serial sections, using “J Images” software in a computer. At least 10 seminiferous tubules were selected randomly and measured per cross section for evaluation of epithelial heights, luminal diameter and total seminiferous tubule diameter. Testicular volumes and seminiferous tubule measurements of treated animals were found to be affected by the chemical sympathectomy with guanethidine with a a statistically significant difference between experimental and control group (p<0.01). Our findings indicate that chemical sympathectomy with-short term low dose guanethidine might display morphometric changes in the rat testis which indicate the presence of autonomic innervation of its parenchyma.
217-219
TECHNICAL NOTE: The Restraint Platform
- refinement of long term restraining of dogs for experimental procedures
by Lars Friis Mikkelsen, Heidi Bentsen & Birgitte Gerlach
All experimental procedures should be evaluated and, if possible, altered to reduce discomfort, pain and/or distress and to enhance the involved animal’s well-being. This short communication describes a new method for the long term restraining of dogs for experimental procedures like multiple blood sampling. The newly developed platform offers the dog a choice either to lie down, sit upright, or stand up, and facilitates an easy blood sampling procedure while ensuring a good and safe restraining of the dog.