Objective—To determine whether rosiglitazone, an agonist of the peroxisome proliferator-activated receptor (PPAR) γ, could alleviate intestinal damage induced by Escherichia coli lipopolysaccharide (LPS) in weaned pigs.
Procedures—Pigs were allocated to 3 treatments (6 pigs/treatment). Control pigs were injected IP with dimethyl sulfoxide and then injected 30 minutes later with sterile saline (0.9% NaCl) solution, LPS-treated pigs were injected IP with dimethyl sulfoxide and then injected 30 minutes later with LPS (100 μg/kg, IP), and rosiglitazone plus LPS-treated pigs were injected with rosiglitazone (3 mg/kg, IP) and then injected 30 minutes later with LPS (100 μg/kg, IP). Pigs were euthanized 3 hours after challenge exposure, and samples of the small intestines were collected for histologic, biochemical, and immunohistochemical examination.
Results—Rosiglitazone alleviated LPS-induced intestinal damage, which was manifested as a lower crypt depth in the duodenum and a higher villus height-to-crypt depth ratio in the duodenum, jejunum, and ileum. Rosiglitazone also mitigated inhibition of crypt cell proliferation in the jejunum and ileum induced by LPS injection. Pretreatment with rosiglitazone significantly increased the number of cells that stained for PPARγ and significantly decreased the number of cells that stained for inducible nitric oxide synthase.
Conclusions and Clinical Relevance—Rosiglitazone alleviated intestinal damage induced by LPS injection in weaned pigs. The protective effects of rosiglitazone on the intestines may be associated with inhibition of intestinal proinflammatory mediators, such as inducible nitric oxide synthase. (Am J Vet Res 2010;71:1331–1338)
Objective—To identify cardiac mechanisms that contribute to adaptation to high altitudes in Tibetan antelope (Pantholops hodgsonii).
Animals—9 male Tibetan antelope and 10 male Tibetan sheep (Ovis aries).
Procedures—Tibetan antelope and Tibetan sheep inhabiting a region with an altitude of 4,300 m were captured, and several cardiac variables were measured. Expression of genes for atrial natriuretic peptide, brain natriuretic peptide, and calcium-calmodulin–dependent protein kinase II δ was measured via real-time PCR assay.
Results—Ratios of heart weight to body weight for Tibetan antelope were significantly greater than those of Tibetan sheep, but ratios of right-left ventricular weights were similar. Mean ± SD baseline heart rate (26.33 ± 6.15 beats/min) and systolic arterial blood pressure (97.75 ± 9.56 mm Hg) of antelope were significantly lower than those of sheep (34.20 ± 6.57 beats/min and 130.06 ± 17.79 mm Hg, respectively). The maximum rate of rise in ventricular pressure in antelope was similar to that in Tibetan sheep, but after exposure to air providing a fraction of inspired oxygen of 14.6% or 12.5% (ie, hypoxic conditions), the maximum rate of rise in ventricular pressure of the antelope increased significantly to 145.1% or 148.1%, respectively, whereas that of the sheep decreased to 68.4% or 70.5%, respectively. Gene expression of calcium-calmodulin–dependent protein kinase II δ and atrial natriuretic peptide, but not brain natriuretic peptide, in the left ventricle of the heart was significantly higher in antelope than in sheep.
Conclusions and Clinical Relevance—Hearts of the Tibetan antelope in this study were well adapted to high-altitude hypoxia as shown by higher heart weight ratios, cardiac contractility in hypoxic conditions, and expression of key genes regulating cardiac contractility and cardiac hypertrophy, compared with values for Tibetan sheep.