Jacobsenkrause1193

Physiological measurements are informative in assessing the relative importance of stressors that potentially impact the health of wildlife. Kelp Gulls, Larus dominicanus (KG), resident to the region of Península Valdés, Argentina, have developed a unique behavior of landing on the backs of southern right whale adults and calves, Eubalaena australis (SRW), where they feed on their skin and blubber. This parasitic behavior results in large open wounds on the dorsal surface of the whale. Coincidently, the SRW population off the coast of Península Valdés has experienced elevated calf mortality. We quantified levels of glucocorticoids and thyroid hormone extracted from baleen of dead calves to evaluate, retrospectively, the endocrine response of whale calves to gull wounding and harassment. Baleen accumulates hormones as it grows, allowing evaluation of long-term trends in physiological condition. While glucocorticoids (GCs) are known to increase in response to stressors such as disturbance, the metabolic hormone triiodothyronine (T3) has been shown to decrease under sustained food deprivation but is largely unaffected by disturbance stress. We quantified lifetime patterns of GCs and T3 in baleen recovered at necropsy from 36 southern right whale calves with varying severity of wounding from KGs. GC levels in baleen correlated positively with the degree of wounding, while T3 levels remained stable irrespective of the severity of the wounding. Our results suggest no evidence of malnutrition in low vs. severely wounded whales. However, the positive correlation of GCs with wound severity indicates that heavily wounded calves are suffering high levels of physiological stress before they die. This suggests that KG wounding may have contributed to the high southern right whale calf mortality observed in the Península Valdés region of Argentina.Myopathies (Woody Breast (WB) and White Striping (WS)) of broiler chickens have been correlated with fast growth. Recent studies reported that localized hypoxia and metabolic impairment may involve in these myopathies of birds. In order to better understand the stress response mechanisms affecting myopathies of broilers, the aim of this study was to examine effects of WB and both WB/WS on stress hormone corticosterone (CORT) levels and expressional changes of stress response genes including glucocorticoid (GC) receptor (GR), 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1), DNA methylation regulators (DNMTs), and arginine vasotocin receptor 1a and 1b (V1aR, V1bR). Results of radioimmunoassay showed that CORT levels of WB and WB/WS birds were significantly higher compared to Con (p less then 0.05), however, the combination of WB/WS was not significantly higher than WB birds, implying that the effects of WB and WS on CORT are not synergistic. see more Hepatic GR expression of both WB and WB/WS birds were significant and circulating CORT level might be a significant biochemical marker of myopathies (WB and WS) of birds. In addition, chronic stress responses in breast muscle and tissue-specific epigenetic changes of stress response genes by DNMTs may play a critical role in the occurrence of myopathies.High carbohydrate diet (HCD) can induce lipid metabolism disorder, characterized by excessive lipid in farmed fish. Peroxisome proliferator activated receptor-α (PPARα) plays an important role in lipid homeostasis. In this study, we hypothesize that PPARα can improve lipid metabolism in fish fed HCD. Fish (3.03 ± 0.11 g) were fed with three diets control (30% carbohydrate), HCD (45% carbohydrate) and HCG (HCD supplemented with 200 mg/kg gemfibrozil, an agonist of PPARα) for eight weeks. The fish fed HCG had higher growth rate and protein effiency than those fed the HCD diet, whereas the opposite trend was observed in feed conversion ratio, hepatosomatic index and mesenteric fat index. Additionally, fish fed HCG significantly decreased lipid accumulation in the whole body, liver and adipose tissues compared to those fed the HCD diet. Furthermore, fish in the HCG group significantly increased the mRNA and protein expression and protein dephosphorylation of PPARα. The HCG group also significantly increased the mRNA level of the downstream target genes of PPARα, whereas the opposite trend occured in the mRNA level of lipolysis-related genes compared to the HCD group. Besides, fish in the HCG group remarkably decreased the contents of alanine aminotransferase, aspartate aminotransferase and malondialdehyde, whereas the opposite occured in the activities of antioxidative enzymes and anti-inflammatory cytokine genes compared to the HCD group. This study indicates that gemfibrozil can improve lipid metabolism and maintain high antioxidant and anti-inflammatory capacity through activating PPARα in Nile tilapia fed a high carbohydrate diet.Ulcerative colitis (UC) is an inflammatory disease characterized by an uncontrolled inflammatory response. Previous study showed that the immunological impairment elicted the alteration of inflammatory mediators, and ferroptosis was implicated with the lethal accumulation of reactive oxygen species (ROS). Therefore, this study aimed to investigate the role of ferroptosis in dextran sulfate sodium (DSS)-induced UC. The animal model was established and the molecular markers of ferroptosis were detected by using western blot. The results suggested that the expression of COX2 and ACSL4 was increased dramatically, while the level of GPX4 and FTH1 was deceased in 3% DSS group compared with Control group (P less then 0.05). Meanwhile, the body weight and colon length were significantly increased, and the inflammation indexes and MDA levels were reduced in 3% DSS+ ferrostatin-1 group, 3% DSS+ liproxstatin-1 group and 3% DSS+ deferprone group compared to 3% DSS group (P less then 0.05). Additionally, the mRNA and protein level of COX2 and ACSL4 were obviously upregulated, but the GPX4 and FTH1 expression were downregulated in 3% DSS group (P less then 0.05); however, the expression level of COX2, ACSL4, GPX4 and FTH1 was revered after ferrostatin-1, liproxstatin-1 (Lip-1) or deferprone (DFP) administration. The immunohistochemical assay showed that the staining intensity of COX2 was decreased and the staining intensity of GPX4 was increased in 3% DSS+ Ferr-1 group compared with 3% DSS group (P less then 0.05). Moreover, the nuclear factor erythoid 2-related 2 (Nrf2) and HO-1 expression were lower in 3% DSS+ Ferr-1 group than 3% DSS group (P less then 0.05). These data revealed that suppressing ferroptosis could effectively ameliorate DSS-induced UC involved in blocking Nrf2/HO-1 signaling pathway.