将促肾上腺皮质激素（ACTH）注入食用蝾螈的肾上腺后，其醛固酮和儿茶酚胺的释放情况。

Release of aldosterone and catecholamines from the interrenal gland of Triturus carnifex in response to adrenocorticotropic hormone (ACTH) administration.

作者信息

Capaldo A, Gay F, Valiante S, Varlese M G, Laforgia V, Varano L

机构信息

Department of Evolutive and Comparative Biology, University of Naples Federico II, 80134 Naples, Italy.

出版信息

J Morphol. 2004 Dec;262(3):692-700. doi: 10.1002/jmor.10269.

DOI:10.1002/jmor.10269

PMID:15487003

Abstract

The influence of adrenocorticotropic hormone (ACTH) on the interrenal gland of Triturus carnifex was investigated by in vivo administration of synthetic ACTH. The effects were evaluated by examination of the ultrastructural morphological and morphometrical features of the tissues as well as the circulating serum levels of aldosterone, noradrenaline (NA), and adrenaline (A). In June and November, ACTH administration increased aldosterone release (from 281.50 +/- 1.60 pg/ml in carrier-injected newts to 597.02 +/- 3.35 pg/ml in June; from 187.45 +/- 1.34 pg/ml in carrier-injected animals to 651.00 +/- 3.61 pg/ml in November). The steroidogenic cells showed clear signs of stimulation, together with a reduction of lipid content in June and an increase of lipid content in November. Moreover, ACTH administration decreased the mean total number of secretory vesicles in the chromaffin cells in June (from 7.73 +/- 0.60 granules/microm2 in carrier-injected animals to 5.91 +/- 0.40 granules/microm2) and November (from 7.78 +/- 0.75 granules/microm2 in carrier-injected newts to 4.87 +/- 0.40 granules/microm2). In June, however, when T. carnifex chromaffin cells contain almost exclusively NA granules (NA: 7.42 +/- 0.86 granules/microm2; A: 0.32 +/- 0.13 granules/microm2), ACTH decreased NA content (5.52 +/- 0.32 granules/microm2) increasing NA release (from 639.82 +/- 3.30 pg/ml in carrier-injected to 880.55 +/- 4.52 pg/ml). In November, when both catecholamines, NA (3.92 +/- 0.34 granules/microm2) and A (3.84 +/- 0.33 granules/microm2), are present in the chromaffin cells, ACTH administration reduced A content (1.02 +/- 0.20 granules/microm2), enhancing adrenaline secretion (from 681.30 +/- 3.62 pg/ml in carrier-injected newts to 1,335.73 +/- 9.03 pg/ml). The results of this study indicate that ACTH influences the steroidogenic tissue, eliciting aldosterone release. The effects on the chromaffin tissue, increase of NA or A secretion, according to the period of chromaffin cell functional cycle, may be direct and/or mediated through the increase of aldosterone release. Finally, the lack of an increase of A content in the chromaffin cells, or A serum level, following ACTH administration in June might suggest an independence of PNMT enzyme on corticosteroids.

摘要

通过体内给予合成促肾上腺皮质激素（ACTH），研究了促肾上腺皮质激素对食用蝾螈肾上腺的影响。通过检查组织的超微结构形态和形态计量学特征以及循环血清中醛固酮、去甲肾上腺素（NA）和肾上腺素（A）的水平来评估其作用。在6月和11月，给予ACTH可增加醛固酮释放（6月时，从注射载体的蝾螈中的281.50±1.60 pg/ml增加到597.02±3.35 pg/ml；11月时，从注射载体的动物中的187.45±1.34 pg/ml增加到651.00±3.61 pg/ml）。类固醇生成细胞显示出明显的刺激迹象，6月时脂质含量减少，11月时脂质含量增加。此外，给予ACTH可减少6月（从注射载体的动物中的7.73±0.60颗粒/μm²减少到5.91±0.40颗粒/μm²）和11月（从注射载体的蝾螈中的7.78±0.75颗粒/μm²减少到4.87±0.40颗粒/μm²）嗜铬细胞中分泌囊泡的平均总数。然而，在6月，当食用蝾螈嗜铬细胞几乎只含有NA颗粒时（NA：7.42±0.86颗粒/μm²；A：0.32±0.13颗粒/μm²），ACTH可降低NA含量（5.52±0.32颗粒/μm²），增加NA释放（从注射载体的动物中的639.82±3.30 pg/ml增加到880.55±4.52 pg/ml）。在11月，当嗜铬细胞中同时存在两种儿茶酚胺，即NA（3.92±0.34颗粒/μm²）和A（3.84±0.33颗粒/μm²）时，给予ACTH可降低A含量（1.02±0.20颗粒/μm²），增强肾上腺素分泌（从注射载体的蝾螈中的681.30±3.62 pg/ml增加到1335.73±9.03 pg/ml）。本研究结果表明ACTH影响类固醇生成组织，引发醛固酮释放。根据嗜铬细胞功能周期的不同阶段，对嗜铬组织的影响，即NA或A分泌增加，可能是直接的和/或通过醛固酮释放增加介导的。最后，6月给予ACTH后嗜铬细胞中A含量或血清A水平未增加，这可能表明苯乙醇胺N -甲基转移酶（PNMT）对皮质类固醇具有独立性。