A low-oxygenated subpopulation of pancreatic islets constitutes a functional reserve of endocrine cells.
A low-oxygenated subpopulation of pancreatic islets constitutes a functional reserve of endocrine cells.
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DOI：
10.2337/db09-0877
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发表时间：
2011-08
期刊：
影响因子：
7.7
通讯作者：
Carlsson PO
中科院分区：
文献类型：
--
作者：
Olsson R;Carlsson PO
胰岛的血流灌注是高度可变的，并受到血糖浓度的严格调节。因此，氧水平被认为是胰岛代谢和功能的关键。尽管在体外对胰岛氧合进行了广泛的研究，但在体内对其知之甚少。本研究旨在探讨体内内分泌胰腺的氧合作用。2-硝基咪唑的还原性代谢，如吡咪唑，在体外和体内的氧代谢研究中已经被广泛使用。当组织氧水平<10 mmHg时，吡莫硝唑在细胞内积聚，此后可通过免疫组织化学方法检测到。研究了正常大鼠、60%部分胰腺切除大鼠和全胰腺移植大鼠胰岛氧合情况。此外，利用放射自显影技术进行亮氨酸依赖蛋白的生物合成，将胰岛氧合与代谢活性联系起来。在体内，正常大鼠胰岛20-25%呈低氧（pO2 <10 mmHg）。通过全胰腺移植，胰岛质量的改变使移植动物内源性胰腺中低氧胰岛的比例增加了一倍，而在60%的部分胰腺切除术后，这一比例几乎完全消失。此外，氧合与代谢有关，因为体内氧合良好的胰岛亮氨酸依赖蛋白的生物合成高50%，其中包括（原）胰岛素的生物合成。目前的研究表明，一种新的休眠低氧胰岛亚群似乎构成了内分泌细胞的功能储备。本研究为胰腺内分泌在葡萄糖稳态中的作用提供了新的视角。
The blood perfusion of pancreatic islets is highly variable and tightly regulated by the blood glucose concentration. Thus, oxygen levels are considered crucial for islet metabolism and function. Although islet oxygenation has been extensively studied in vitro, little is known about it in vivo. The current study aimed to investigate the oxygenation of the endocrine pancreas in vivo. The reductive metabolism of 2-nitroimidazoles, such as pimonidazole, has previously been extensively used in studies of oxygen metabolism both in vitro and in vivo. At tissue oxygen levels <10 mmHg, pimonidazole accumulates intracellularly and may thereafter be detected by means of immunohistochemistry. Islet oxygenation was investigated in normal, 60% partially pancreatectomized, as well as whole-pancreas–transplanted rats. Moreover, leucine-dependent protein biosynthesis was performed using autoradiography to correlate islet oxygenation with metabolic activity. In vivo, 20–25% of all islets in normal rats showed low oxygenation (pO2 <10 mmHg). Changes in the islet mass, by means of whole-pancreas transplantation, doubled the fraction of low-oxygenated islets in the endogenous pancreas of transplanted animals, whereas this fraction almost completely disappeared after a 60% partial pancreatectomy. Moreover, oxygenation was related to metabolism, since well-oxygenated islets in vivo had 50% higher leucine-dependent protein biosynthesis, which includes (pro)insulin biosynthesis. The current study suggests a novel subpopulation of dormant low-oxygenated islets, which seems to constitute a functional reserve of endocrine cells. This study establishes a novel perspective on the use of the endocrine pancreas in glucose homeostasis.
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DOI：
10.1152/ajpendo.00044.2002
发表时间：
2002-09-01
影响因子：
5.1
作者：
Carlsson, PO;Olsson, R;Jansson, L
通讯作者：
Jansson, L
DOI：
10.1046/j.1365-201x.2002.01049.x
发表时间：
2002-12-01
期刊：
ACTA PHYSIOLOGICA SCANDINAVICA
影响因子：
--
作者：
Carlsson, PO;Jansson, L;Palm, F
通讯作者：
Palm, F
影响因子：
11.2
作者：
Franco, M;Man, S;Kerbel, RS
通讯作者：
Kerbel, RS
影响因子：
4.8
作者：
Johansson, M;Mattsson, G;Carlsson, PO
通讯作者：
Carlsson, PO
影响因子：
6
作者：
Gardiner, TA;Gibson, DS;Stitt, AW
通讯作者：
Stitt, AW