• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.97-102
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• 1991

Subcellular location of five isozymes in Populus species was studied by isozyme analysis with plant and mitochondria. Isozymes analyzed were ADH, 6-PGD, MDH, PGI, and Diaptrorase. ADH seems to be cytosolic isozyme encoded with nuclear genes at one locus, while 6-PGD seems to be mitochondrial one. MDH showed three hands in cytosol and four other bands in mitochondria. Three cytosolic hands were showed for PGI. Diaphorase showed one mitochodrial band and two cytosofic bands which seemed to the encoded by nuclear genes at one locus.

• BMB Reports
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• v.55 no.11
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• pp.528-534
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• 2022

Mitochondria are cellular organelles that perform various functions within cells. They are responsible for ATP production, cell-signal regulation, autophagy, and cell apoptosis. Because the mitochondrial proteins that perform these functions need Ca²⁺ ions for their activity, mitochondria have ion channels to selectively uptake Ca²⁺ ions from the cytoplasm. The ion channel known to play the most important role in the Ca²⁺ uptake in mitochondria is the mitochondrial calcium uniporter (MCU) holo-complex located in the inner mitochondrial membrane (IMM). This ion channel complex exists in the form of a complex consisting of the pore-forming protein through which the Ca²⁺ ions are transported into the mitochondrial matrix, and the auxiliary protein involved in regulating the activity of the Ca²⁺ uptake by the MCU holo-complex. Studies of this MCU holo-complex have long been conducted, but we didn't know in detail how mitochondria uptake Ca²⁺ ions through this ion channel complex or how the activity of this ion channel complex is regulated. Recently, the protein structure of the MCU holo-complex was identified, enabling the mechanism of Ca²⁺ uptake and its regulation by the MCU holo-complex to be confirmed. In this review, I will introduce the mechanism of action of the MCU holo-complex at the molecular level based on the Cryo-EM structure of the MCU holo-complex to help understand how mitochondria uptake the necessary Ca²⁺ ions through the MCU holo-complex and how these Ca²⁺ uptake mechanisms are regulated.

• Proceedings of the Korean Nutrition Society Conference
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• 1992.05a
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• pp.20-21
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• 1992

• The Korean Journal of Zoology
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• v.11 no.1
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• pp.5-12
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• 1968

The membrane structures were electron microscopically studied in the elongating lens fibers of the regenerating lens of adult Triturus pyrrhogaster. Observations were focused on the endoplasmic reticulum and mitochondria. The endoplasmic reticulum developed in the vicinity of the nucleus with active blebbing of the outer membrane. At the same time, the concentration of mitochondria around the rough-surfaced endoplasmic reticulum near by the nucleus was always observed. Both endoplasmic reticulum and mitochondrion undergo disintegration in the apical portion apart from the nucleus. Some considerations were discussed with reference to published data.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.181-186
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• 2012

Fenofibrate is a selective peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) activator and is prescribed to treat hyperlipidemia. The mechanism through which $PPAR{\alpha}$ agonists reduce food intake, body weight, and adiposity remains unclear. One explanation for the reduction of food intake is that fenofibrate promotes fatty acid oxidation and increases the production of ketone bodies upon a standard experimental dose of the drug (100~300 mg/kg/day). We observed that low-dose treatment of fenofibrate (30 mg/kg/day), which does not cause significant changes in ketone body synthesis, reduced food intake in Long-Evans Tokushima (LETO) rats. LETO rats are the physiologically normal controls for Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which are obese and cholecystokinin (CCK)-A receptor deficient. We hypothesized that the reduced food intake by fenofibrate-treated LETO rats may be associated with CCK production. To investigate the anorexic effects of fenofibrate in vivo and to determine whether CCK production may be involved, we examined the amount of food intake and CCK production. Fenofibrate-treated OLETF rats did not significantly change their food intake while LETO rats decreased their food intake. Treatment of fenofibrate increased CCK synthesis in the duodenal epithelial cells of both LETO and OLETF rats. The absence of a change in the food intake of OLETF rats, despite the increase in CCK production, may be explained by the absence of CCK-A receptors. Contrary to the OLETF rats, LETO rats, which have normal CCK receptors, presented a decrease in food intake and an increase in CCK production. These results suggest that reduced food intake by fenofibrate treatment may be associated with CCK production.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.259-265
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• 2014

Mitochondrial DNA (mtDNA)-depleted (${\rho}^0$) cells are often used as mtDNA recipients to study the interaction between the nucleus and mitochondria in mammalian cells. Therefore, it is crucial to obtain mtDNA-depleted cells with many different nuclear backgrounds for the study. Here, we demonstrate a rapid and reliable method to isolate mammalian mtDNA-depleted cells involving treatment with the antimitochondrial agents ethidium bromide (EtBr) and 2',3'-dideoxycytidine (ddC). After a short exposure to EtBr or ddC, followed by rapid clonal isolation, we were able to generate viable mtDNA-depleted cells from mouse and human cells and were able to successfully repopulate them with exogenous mitochondria from platelets isolated from mouse and human blood samples. These mtDNA-depleted cells can be used to characterize the nuclear mitochondrial interactions and to study mtDNA-associated defects in mammalian cells. Our method of isolating mtDNA-depleted cells is practical and applicable to a variety of cell types.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.286-291
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• 2007

The bitterling, Acheilognathus koreensis spermatozoon has been examined by electron microscopy. The epididymal spermatozoa of A. koreensis are representing typical characteristic of cyprinid spermatozoa including the lateral insertion of flagellum, the organization of centriolar complex in shallow nuclear fossa and the asymmetrical arrangement of mitochondria. The sperm mid-piece contains a large mitochondrion characteristic enclosed by membranous vesicles. The mitochondria aspect is different from that of other cyprinid spermatozoa, which their mitochondria have a conventional aspect and never fuse to form a mitochondrial derivative. In term of sperm evolution, the fused mitochondria are regarded as the apomorphic character in comparison with the separate mitochondria. The single mitochondrion is not found in cyprinid spermatozoon except for Rodeus and Pungtungia.

• Journal of Chest Surgery
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• v.19 no.2
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• pp.197-208
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• 1986

Propranolol is one of clinically useful antiarrhythmic agents and electrophysiologically classified as group II. And the negative inotropic effect which is not related to adrenolytic effect has been demonstrated with high concentration of propranolol. On the other hand, it has been well known that the calcium plays a central role in excitation-contraction coupling process of myocardium and also in electrophysiological changes of cell membrane. Author studies the effect of propranolol on calcium uptake and release in sarcoplasmic reticulum and mitochondria prepared from porcine myocardium to investigate the mechanism of action of propranolol on myocardium. The results are summarized as follow: 1] The maximum Ca++-uptake of sarcoplasmic reticulum is inhibited by propranolol in a dose dependent manner. 2] The release of calcium from sarcoplasmic reticulum is not affected by propranolol but with higher than 1x10-3 M of propranolol, rate of calcium release from sarcoplasmic reticulum is decreased. 3] Propranolol inhibits the maximum uptake and uptake rate of calcium in mitochondria non-competitively. [Ki = 6.21 x 10-4 M] 4] The rate of Na+ induced calcium release from mitochondrion shows a function of [Na+]2 and is inhibited by propranolol with the concentration significantly lower than that affect the calcium uptake in sarcoplasmic reticulum and in mitochondria [Ki = 2.91 x 10-5 M]. These results suggest that propranolol affects the intracellular calcium homeostasis which may considered to be one of the mechanism of action of propranolol on myocardium.

• Applied Microscopy
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• v.26 no.3
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• pp.315-328
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• 1996

This study aims to demonstrate the effect of SOD (superoxide dismutase), one of the antioxidant enzymes, on the ultrastructural changes in the parietal cells caused by the administration of cisplatin in the rat. A total of 60 healthy Sprague-Dawley rats weighing about 200 gm were used as experimental animals. Cisplatin (6 mg/kg) was administered intraperitoneally to rats pretreated with 15,000 unit/kg of SOD or rats without the pretreatment. The experimental animals were sacrificed at 6 hours, 12 hours, 24 hours and 3 days after the administration of cisplatin. The results were as follows: 1. SOD alone did not affect the ultrastructural changes in the gastric parietal cells in the rat. 2. Irregular shaped mitochondria, mitochondria with dim cristae, dilated cristae, ruptured outer membrane, electron lucent matrix and degenerative mitochondria were seen in cisplatin treated rat. Whorled membranous body, many lysosomes and large vacuole were observed in the gastric parietal cells in cisplatin treated rat. 3. Mitochondria with dilated cristae and electron lucent matrix and irregular shaped mitochondria were observed in the gastric parietal cells of the cisplatin treated rat with pretreatment of SOD. These results suggest that SOD attenuates the toxic effect of the cisplatin in the gastric parietal cells of the rat.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.12-12
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• 2001

To get insight into the nature of foreign mitochondria and syngamy during mammalian fertilization we compared fertilization processes in porcine oocytes following microinjection of porcine or mouse spermatozoa. Pronuclear movement, sperm mitochondria, and DNA synthesis were imaged with propidium iodide, mitotracker, and BrdU under confocal laser scanning microscope. Intracytoplasmic injection of either porcine or mouse spermatzoon activated porcine oocytes without additional parthengenetic stimulation. Foreign mitochondria in either mouse or porcine sperm midpiece were introduced into porcine oocytes following sperm injection, but rapidly disappeared from the actively developing porcine oocytes. BrdU experiment showed new DNA synthesis in porcine oocytes following injection of mouse spermatozoon or sperm head. At 24 h after injection of mouse isolated sperm head or a spermatozoon, mitoic metaphase was seen in oocyte, but they did not go to normal cell division (Table). These results suggest that pronuclear formation, foreign mitochondria disruption, DNA synthesis and syngamy formation during fertilization are not species specific processes.(Table Omitted).