RESUMO
Allopreening occurs in many species of birds and is known for providing hygienic and social benefits. While this behavior has been extensively studied among conspecifics, its occurrence among different species remains little known. Outside of captive environments, only a few records of interspecific allopreening exist. In this study, we describe our observations of the interspecific allopreening behavior between Spot-necked (Stachyris strialata) and Nonggang Babblers ( S. nonggangensis) in a non-captive environment in southern China. To our knowledge, these observations represent the first record of interspecific allopreening in the family Timaliidae. We suggest that this understudied behavior is most likely related to the dominant-subordinate relationship between these two species: either the dominant species preening the subordinate species to assert dominance or the subordinate species preening the dominant species to reduce tensions by appeasement. We also suggest interspecific allopreening may not be as rare as we thought if we study this behavior under circumstances where different species are close to each other. This study contributes to our understanding of not only the potential mechanism(s) behind interspecific allopreening but also the behavioral ecology of the vulnerable Nonggang Babbler.
RESUMO
OBJECTIVE: To observe the effects of medium and long-term insulin pretreatment on the activity of main oxidase and antioxidant enzyme in the myocardium of burned rats with delayed fluid resuscitation. METHODS: According to random number table method, forty male Sprague-Dawley (SD) rats were divided into pseudo-burn group, burn delayed resuscitation group, insulin glargine pretreatment group and neutral protamine hagedorn (NPH) insulin pretreatment group, with 10 rats in each group. 30% total body surface area (TBSA) as III degree scald model was prepared by bathing the back of rats in 95 centigrade hot water for 15 s; the rats in the pseudo-burn group were immersed in 37 centigrade warm water for 15 s as control. Insulin glargine pretreatment group, NPH insulin pretreatment group and burn delayed resuscitation group were injected subcutaneously with insulin glargine, NPH insulin, and normal saline 1.0 U×kg-1×d-1 2 hours after injury, and intraperitoneal injection of normal saline 40 mL/kg simulated delay resuscitation 6 hours after injury. The pseudo-burn group didn't receive medicine and delayed resuscitation. Abdominal aortic blood samples and heart tissue were collected immediately after simulating scald in the pseudo-burn group, and 24 hours after scald in three burn groups. Blood glucose, xanthine oxidase (XOD), myeloperoxidase (MPO), CuZn-superoxide dismutase (CuZn-SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) of the heart tissue were determined by spectrophotometry. RESULTS: Compared with the pseudo-burn group, the burn delayed resuscitation group have significantly higher blood glucose level and the XOD and MPO in the heart tissue, while significantly lower CuZn-SOD, CAT, and GSH-Px in the heart tissue. Compared with the burn delayed resuscitation group, insulin glargine pretreatment group and NPH insulin pretreatment group have lower blood glucose level and heart tissue XOD [blood glucose (mmol/L): 6.37±1.22, 6.66±1.45 vs. 9.47±0.80; XOD (U/g): 271.93 (261.59, 275.91), 285.32 (251.96, 297.29) vs. 363.37 (354.12, 377.76), all P < 0.05], while significantly higher heart tissue CuZn-SOD, CAT, and GSH-Px [CuZn-SOD (U/g): 0.13±0.01, 0.14±0.01 vs. 0.10±0.01; CAT (U/g): 29.17±7.28, 27.16±7.37 vs. 18.36±4.53; GSH-Px (U/g): 0.33 (0.16,0.41), 0.30 (0.17,0.41) vs. 0.07 (0.04,0.11), all P < 0.05]. MPO activity in insulin glargine pretreatment group was significantly lower than that in burn delayed resuscitation group (U/g: 0.016±0.002 vs. 0.020±0.002, P < 0.05), but there was no significant difference between insulin pretreatment group and NPH insulin pretreatment group (U/g: 0.019±0.003 vs. 0.020±0.002, P > 0.05). There was no significant difference in the blood glucose, and activities of XOD, MPO, CAT, GSH-Px between insulin glargine pretreatment group and NPH insulin pretreatment group, but the activity of CuZn-SOD in NPH insulin pretreatment group was further higher than that in insulin glargine pretreatment group (U/g: 0.14±0.01 vs. 0.13±0.01, P < 0.05). CONCLUSIONS: Medium and long-term insulin pretreatment can improve the antioxidant capacity of myocardium in delayed resuscitation rats after burns, inhibit the production of reactive oxygen species and improve the scavenging capacity of reactive oxygen species. However, only CuZn-SOD activity is different between the two groups, and further study needs to be carried out to determine whether it is related to the type if insulin.
