Effect of adrenocorticotropin on the concentration of triglyceride in the adrenal gland of the hypophysectomized rat.
Effect of adrenocorticotropin on the concentration of triglyceride in the adrenal gland of the hypophysectomized rat.
复制标题
促肾上腺皮质激素对垂体切除大鼠肾上腺甘油三酯浓度的影响。
DOI：
10.1210/endo-78-5-1087
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发表时间：
1966
期刊：
影响因子：
4.8
通讯作者：
L. A. Garcia
中科院分区：
文献类型：
--
作者：
D. Rudman;L. A. Garcia
Van Handel和Zilversmit法测得正常大鼠肾上腺甘油三酯浓度为2.2 ~ 3.2 mg/100 mg新鲜组织；垂体切除术后24-48小时，该值增加到3.5-4.8 mg/100 mg组织。垂体切除术后24-48小时注射0.1-10 U促肾上腺皮质激素可使肾上腺甘油三酯浓度降低20-45%。这种效果在注射后3小时明显，并持续至少6小时。（内分泌学78:1087,1966）观察首次揭示肾上腺皮质含有大量的脂质，单次注射促肾上腺皮质激素（ACTH）或各种急性有害刺激可使其消耗(1)。皮质脂质的化学性质是许多研究的对象，这些研究一致认为肾上腺胆固醇酯在促肾上腺皮质刺激下会降低，而肾上腺磷脂浓度保持不变（1-4）。然而，肾上腺甘油三酯含量在急性应激刺激下增加(4)、不变(3)或减少(2)。这些不一致的数据是通过计算甘油三酯含量的间接方法获得的，因为直到最近才有一种针对这种脂质的特定分析方法。Van Handel和Zilversmit(5)提出了一种直接测定甘油三酯的方法，并认识到ACTH对脂肪细胞甘油三酯代谢的影响，这使我们重新审视ACTH对大鼠肾上腺甘油三酯含量的可能影响。材料与方法从Charles River实验室获得完整和去垂体的雄性Wistar大鼠，体重250-260 g，饲喂Purina Laboratory Checkers。实验于垂体切除术后2448小时开始。将完整的和去垂体的大鼠皮下注射0.5 ml生理盐水或0.1-10 U临床猪ACTH（威尔逊实验室）0.5 ml。在此后的规定时间内，动物因颈椎骨折而死亡。由美国公共卫生服务部资助AM-06056， HE05741和HE-00052，以及纽约市卫生研究委员会资助U-1562。在解剖显微镜下切除无外源性组织，称量后用氯仿/甲醇2:1 （20 ml溶剂/一对肾上腺）均质。参照Folch et al.(6)对氯仿/甲醇提取物进行洗涤，然后用Van Handel和Zilversmit(6)的方法分析甘油三酯，用Abell et al.(7)的方法分析总胆固醇。结果正常大鼠肾上腺甘油三酯浓度在2.2 ~ 3.2 mg/100 mg新鲜组织之间，垂体去骨大鼠（未给予ACTH）肾上腺甘油三酯浓度在3.5 ~ 4.8 mg/100 mg组织之间；3个实验中，两组间差异均有统计学意义（p < 0.025）（表1）。去垂体大鼠注射10 U ACTH， 6小时后肾上腺甘油三酯浓度降低有统计学意义（p < 0.01）；这种下降幅度在注射前浓度的33%到44%之间（见表1、2、3）。甘油三酯浓度降低的幅度在0.1-10 U激素范围内与ACTH剂量成正比（图3，表1）；然而，在0.1 U之后，甘油三酯降低的统计学意义值得怀疑。0.1- 10u ACTH产生的肾上腺甘油三酯的消耗与肾上腺胆固醇含量的平行下降有关（见表3），正如Sayers及其同事最初所描述的(1)。注射10 U ACTH后，肾上腺甘油三酯在3小时内明显降低，并持续至少6小时（表2）。这些数据表明ACTH不仅降低了去垂体大鼠肾上腺中胆固醇的浓度，而且降低了甘油三酯的浓度。
The concentration of triglyceride in the adrenal gland, measured by the method of Van Handel and Zilversmit, was found to be 2.2-3.2 mg/100 mg fresh tissue in the normal rat; this value increased to 3.5-4.8 mg/100 mg tissue 24-48 hr after hypophysectomy. Injection of 0.1-10 U of adrenocorticotropin in the rat 24-48 hr after hypophysectomy caused a 20-45% reduction in adrenal triglyceride concentration. This effect was apparent 3 hr after injection and persisted for at least 6 hr. {Endocrinology 78:1087, 1966) H observations first revealed that the adrenal cortex contains an abundant quantity of lipid, which is depleted by a single injection of adrenocorticotropin (ACTH) or by a variety of acute noxious stimuli (1). The chemical nature of the cortical lipid thus depleted has been the object of numerous studies, which agree that adrenal cholesterol esters are reduced by an adrenocorticotropic stimulus and that adrenal phospholipid concentration remains unchanged (1-4). Adrenal triglyceride content, however, has been reported increased (4), unchanged (3), or decreased (2) in animals subjected to acute stressful stimuli; these discordant data were obtained with indirect methods for calculating triglyceride content, since a specific analytic method for this lipid was not available until recently. The introduction by Van Handel and Zilversmit (5) of a direct method for determining triglyceride, and recognition of the influence of ACTH on the triglyceride metabolism of the fat cell, have led us to re-examine the possible effect of ACTH on the triglyceride content of the rat's adrenal gland. Materials and Methods Intact and hypophysectomized male Wistar rats weighing 250-260 g were obtained from Charles River Laboratories and were fed Purina Laboratory Checkers ad lib. The experiments were begun 2448 hr after hypophysectomy. Intact and hypophysectomized rats were injected subcutaneously with 0.5 ml normal saline or with 0.1-10 U clinical porcine ACTH (Wilson Laboratories) in a volume of 0.5 ml. At stated periods thereafter, the animals were killed by cervical fracture, the adrenal glands Received December 10,1965. Supported by USPHS Grants AM-06056, HE05741 and HE-00052, and by Grant U-1562 from the Health Research Council of New York City. 1 Career Scientist of the Health Research Council of New York City under Contract 1-118. were dissected free of extraneous tissue under a dissecting microscope, weighed and homogenized in chloroform/methanol 2 :1 (20 ml of solvent/pair of adrenals). The chloroform /methanol extract was washed according to Folch et al. (6) and then was analyzed for triglyceride by the method of Van Handel and Zilversmit (6), and for total cholesterol by the method of Abell et al. (7). Results The triglyceride concentration in the adrenal glands of normal rats ranged between 2.2 and 3.2 mg/100 mg fresh tissue, while the concentration in the adrenals of hypophysectomized rats (not treated with ACTH) ranged between 3.5 and 4.8 mg/100 mg tissue; the difference between these 2 groups was statistically significant (p <.025) in each of 3 experiments (Table 1). Injection of 10 U ACTH in the hypophysectomized rat caused a statistically significant (p <.01) reduction in adrenal triglyceride concentration 6 hr later; this decrease ranged between 33 and 44% of the preinjection concentration (Expt. 1, 2, 3, Table 1). The magnitude of the reduction in triglyceride concentration was proportional to the dose of ACTH in the range 0.1-10 U of hormone (Expt. 3, Table 1); following 0.1 U, however, the triglyceride decrease was of doubtful statistical significance. The depletion of adrenal triglyceride produced by 0.1-10 U of ACTH was associated with a parallel decline in adrenal cholesterol content (Expt. 3, Table 1), as originally described by Sayers and colleagues (1). The reduction in adrenal triglyceride following injection of 10 U ACTH was apparent at 3 hr and persisted for at least 6 hr (Table 2). Discussion These data demonstrate that ACTH reduces the concentration not only of cholesterol, but also of triglyceride, in the adrenal gland of the hypophysectomized rat.