Zhang S H, Hennessy D P, Cranwell P D
School of Agriculture, La Trobe University, Bundoora, Victoria, Australia.
Am J Vet Res. 1990 Jul;51(7):1021-5.
A study was conducted to determine whether differences in adrenocortical response to exogenous adrenocorticotrophin (ACTH) were an accurate reflection of an animal's perception of and response to stressful stimuli, or whether the pituitary gland might modulate adrenocortical responsiveness. Sixteen Large White x Landrace female pigs, of which 8 had high adrenocortical response to ACTH and the other 8 had low response, were administered IV a bolus of synthetic human corticotropin-releasing factor (hCRF) at dose rates ranging from 0.002 to 2 micrograms/kg of body weight. Blood samples were collected at known times for up to 2 hours after administration of hCRF. Plasma ACTH and cortisol concentrations were measured by radioimmunoassay. Results indicate that hCRF stimulated the pituitary gland of high- and low-responding pigs to secrete ACTH, which in turn stimulated the adrenal cortex to secrete cortisol. Plasma ACTH concentration, before or after hCRF administration, was not significantly different between the high and low responders. However, high-responding pigs had higher cortisol concentration after hCRF administration than did low-responding pigs. Thus, the differences in adrenocortical response to ACTH between the 2 groups of pigs were not attenuated by variation in pituitary response. It is concluded that adrenocortical responsiveness to ACTH is an accurate indicator of the perception of and the response to stress.
进行了一项研究，以确定肾上腺皮质对外源性促肾上腺皮质激素（ACTH）的反应差异是否准确反映了动物对压力刺激的感知和反应，或者垂体是否可能调节肾上腺皮质反应性。16头大白猪与长白猪的杂交雌性猪，其中8头对ACTH的肾上腺皮质反应高，另外8头反应低，以0.002至2微克/千克体重的剂量静脉注射合成人促肾上腺皮质激素释放因子（hCRF）。在注射hCRF后长达2小时的已知时间采集血样。通过放射免疫测定法测量血浆ACTH和皮质醇浓度。结果表明，hCRF刺激高反应和低反应猪的垂体分泌ACTH，进而刺激肾上腺皮质分泌皮质醇。在注射hCRF之前或之后，高反应者和低反应者之间的血浆ACTH浓度没有显著差异。然而，注射hCRF后，高反应猪的皮质醇浓度高于低反应猪。因此，两组猪对ACTH的肾上腺皮质反应差异并未因垂体反应的变化而减弱。得出的结论是，肾上腺皮质对ACTH的反应性是对压力的感知和反应的准确指标。
