Turton J A, Ladds P W, Manolis S C, Webb G J
Department of Biomedical and Tropical Veterinary Sciences, James Cook University of North Queensland, Townsville.
Aust Vet J. 1997 Feb;75(2):114-9. doi: 10.1111/j.1751-0813.1997.tb14170.x.
To examine whether sub-optimal temperature induced stress and immunosuppression in farmed saltwater crocodile (Crocodylus porosus) hatchlings.
A clinico-pathological study.
A total of 140 hatchlings were used.
Body weight and length, plasma corticosterone and immunoglobulin concentrations and total and differential white blood cell counts were measured in 140 hatchlings from five clutches divided between five water temperature treatment groups. Initially all groups were housed at 32 degrees C for 10 weeks, then two groups (L, LC) were changed to low temperature (28 degrees C) and two groups (H, HC) to high temperature (36 degrees C), while one group (C) remained at 32 degrees C. The LC and HC groups were maintained at these temperatures for 10 days, after which the water temperature of both groups was returned to 32 degrees C. Blood samples were collected twice (at 6 and 9 weeks of age) before the initial temperature change, and at 10 days and 4 weeks after the initial temperature change (at 11.5 and 14 weeks of age).
Except for an increase in plasma corticosterone in the HC group and a decrease in the L group when the temperature change was first introduced, changes in plasma corticosterone were not significant. There were no significant changes in immunoglobulin concentrations. There were, however, significant decreases in the total white cell and lymphocyte counts in the LC group after the temperature was decreased to 28 degrees C, and an increase in these counts after water temperature was returned to 32 degrees C. Clutch of origin had significant effects on body weight and length gains, and there were negative relationships between body weight and corticosterone concentrations and between body weight and immunoglobulin concentrations.
As haematological changes indicative of stress were not associated with significant changes in serum corticosterone, immunosuppression in young crocodiles may be independent of the hypothalamic-pituitary-adrenal cortical axis.
研究养殖的咸水鳄（湾鳄）幼鳄在亚适宜温度下是否会产生应激和免疫抑制。
一项临床病理学研究。
共使用了140只幼鳄。
对来自五个窝卵的140只幼鳄进行分组，分入五个水温处理组，测量其体重、体长、血浆皮质酮和免疫球蛋白浓度以及白细胞总数和分类计数。最初所有组均在32℃饲养10周，然后两组（L组、LC组）改为低温（28℃），两组（H组、HC组）改为高温（36℃），而一组（C组）保持在32℃。LC组和HC组在这些温度下维持10天，之后两组水温恢复到32℃。在初始温度变化前（6周龄和9周龄时）、初始温度变化后10天和4周（11.5周龄和14周龄时）采集血样两次。
除了温度刚变化时HC组血浆皮质酮增加和L组减少外，血浆皮质酮变化不显著。免疫球蛋白浓度无显著变化。然而，LC组温度降至28℃后白细胞总数和淋巴细胞计数显著下降，水温恢复到32℃后这些计数增加。窝卵来源对体重和体长增加有显著影响，体重与皮质酮浓度以及体重与免疫球蛋白浓度之间呈负相关。
由于指示应激的血液学变化与血清皮质酮的显著变化无关，幼鳄的免疫抑制可能独立于下丘脑-垂体-肾上腺皮质轴。
