• Proceedings of the PSK Conference
• /
• 2003.10a
• /
• pp.66-69
• /
• 2003

Mast cell playa crucial role in allergic and inflammatory disease through the exocytosis of preformed granule-associated mediators, such as histamine, serotonin, proteases and the generation of newly synthesized lipid mediators such as, leucotrien (LT) $C_4$ and prostaglandin (PG) $D_2$ in response to crosslinking of high affinity for IgE (Fc$\gamma$RI). New eicosanoids are synthesized by the oxidative metabolism of arachidonic acid, which is generally esterified sn-2 position of the major classes of glycerophospholipids. (omitted)

• Parasites, Hosts and Diseases
• /
• v.60 no.5
• /
• pp.357-360
• /
• 2022

Excretory-secretory products (ESP) of T. vaginalis have been shown to inhibit sperm motility, viability, and functional integrity, leading to a decreased fertilization rate in vitro. This study investigated whether T. vaginalis induce apoptosis and ultrastructural changes of sperm using flow cytometry and electron microscopy. Incubation of sperm with T. vaginalis ESP increased phosphatidylserine externalization and DNA fragmentation, and decreased mitochondrial membrane potential. Transmission electron microscopy of sperm incubated with ESP revealed abnormal features such as distorted heads, broken necks, and acrosomes exocytosis. This is the first report that demonstrates a direct impact of T. vaginalis ESP on sperm apoptosis and architecture in vitro.

• Applied Microscopy
• /
• v.51
• /
• pp.2.1-2.7
• /
• 2021

Synaptic vesicles, which are endogenous to neurotransmitters, are involved in exocytosis by active potentials and release neurotransmitters. Synaptic vesicles used in neurotransmitter release are reused via endocytosis to maintain a pool of synaptic vesicles. Synaptic vesicles show different types of exo- and endocytosis depending on animal species, type of nerve cell, and electrical activity. To accurately understand the dynamics of synaptic vesicles, direct observation of synaptic vesicles is required; however, it was difficult to observe synaptic vesicles of size 40-50 nm in living neurons. The exo-and endocytosis of synaptic vesicles was confirmed by labeling the vesicles with a fluorescent agent and measuring the changes in fluorescence intensity. To date, various methods of labeling synaptic vesicles have been proposed, and each method has its own characteristics, strength, and drawbacks. In this study, we introduce methods that can measure presynaptic activity and describe the characteristics of each technique.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.5
• /
• pp.1391-1398
• /
• 2005

The anti-thrombic properties of the oriental herbal medicine Daejowhan(DJW, 大造丸) which consists of 11 kinds of herbs (indicated as ratio) of Rehmanniae Radix 24%, Hominis Placenta 5%, Testudinis Carapax 9%, Eucommiae Cortex 9%, Asparagi Radix 9%, Phellodendri Cortex 9%, Achyranthis Radix 7%, Liriopis Tuber 7%, Angelicae Sinensis Radix 7%, Ginseng Radix 5% and Schizandrae Fructus 3% were investigated. The water extracts from DJW inhibited Platelet-activating factor(PAF) induced platelet aggregation. DJW was extracted with methanol and further fractionated by ethylacetate. A 70% methanol extract showed a strong inhibition against PAF-induced aggregation in vitro and in vivo assays. The ethylacetate soluble fraction was shown to have inhibitory effect on PAF-induced platelet aggregation in vitro assay. The ethylacetate soluble fraction specially protected against the lethality of PAF, while verapamil did not afford any protection. These results indicate that the water extracts and alcoholic-fractions inhibit the action of PAF in vivo by an antagonistic effect on PAF, so that it may be useful in treating disorders caused by PAF, such as acute allergy, inflammation, asthma, gastrointestinal ulceration, toxic shock and so forth. DJW was investigated regarding its assumed anti-thrombic action on human platelets which was deduced from its ability to suppress Arachidonic acid(AA)-induced aggregation, exocytosis of ATP, and inhibition of Cyclooxygenase(COX) and Thromboxane synthase(TXS) activity. The latter two effects were estimated from the generation of Prostaglandin $E_2(PGE_2)$ and Thromboxane $A_2(TXA_2)$ respectively. Exogenously applied AA ($100{\mu}mol/{\ell}$) provoked a $89\%$ aggregation of platelets, the release of 14 pmol ATP, and the formation of either 225 pg $TXA_2$ or 45 pg $PGE_2$, each parameter being related to 106 platelets. An application of DJW 5 min before AA dose-dependently diminished aggregation, ATP-release and the synthesis of $TXA_2$ and $PGE_2$ with $IC_{50}$ values of 74, 108, 65, $72{\mu}g/m{\ell}$, respectively. The similarity of the $IC_{50}$ values suggest an inhibition of COX by DJW as primary target, thus suppressing the generation of $TXA_2$ which induces aggregation of platelets and exocytosis of ATP by its binding on $TXA_2$-receptors.

• KSBB Journal
• /
• v.29 no.5
• /
• pp.328-335
• /
• 2014

Vehicle toxicity is one of the main obstacles for intracellular delivery of bioactive compounds. Silk fibroin is a natural polymer proven to have high biocompatibility since being used as suture material. In this report, fibroin microspheres were prepared without any chemical modification or cross-linking not to affect its biocompatibility. The microspheres were taken up by more than 90% of 3T3 cells. Cellular uptake continued after medium replenishment with a different-colored fluorescent microsphere, suggesting that simultaneous ingestion and exocytosis occurred. Cellular uptake of fibroin microspheres did not affect cell viability. Intracellular trafficking of the microspheres using lysosome-specific fluorescent dye revealed that fibroin microspheres were localized both in the cytoplasm and in the lysosome. Accordingly, fibroin microspheres can be a potential vehicle for intracytoplasmic delivery of large cargos, such as mixtures of proteins, nutrients or artificial organelles.

• Toxicological Research
• /
• v.14 no.3
• /
• pp.341-348
• /
• 1998

We established an in vitro experimental system using the following procedure. We first introduced tritium-labelled norepinephrine ([3H]-NE)into PC12 cells. The [3H]-NE incorporated into PC12 cells were then stimulated by a high concentration (60 mM) of $K^+$ during 12 minutes. Then, we counted the amount of [3H]-NE release from PC12 cells with the scintillation counter. After screening fungal, Streptomyces or bacterial product using this experimental system, we obtained S9940 from Streptomyces spp. which inhibited [3H]-NE release from PC12 cells. S9940 also inhibits the release of ATP as a neurotransmitter of PC12 cells and rat cortical neurons. The inhibitory effect was seen even when the PC12 cells were treated with low $K^+$ buffer containing ionomycin $(1\muM)$ as an ionopore. This result suggests that the inhibitory action of S9940 on neurotransmitter release appeared after the influx of $Ca^{2+}$.

• Journal of Veterinary Clinics
• /
• v.21 no.2
• /
• pp.209-213
• /
• 2004

A 8 kg, 3-year-old male West Highland white terrier dog with a 1.5-year history of chronic, severely pruritic, seborrheic skin disorder was referred to the Veterinary Medical Teaching Hospital of the Tokyo University of Agriculture and Technology. On physical examination, lesions were observed on entire cutaneous surface, except for face, dorsum of body, and footpads. Skin lesions were characterized by diffuse erythema, erythematous papules, severe alopecia, hyperpigmentation, and lichenification. Tape strip tests of skin lesions revealed cocci and Malassezia infections. The intradermal allergy tests revealed positive reactions to Japanese cedar pollen, but the non-seasonal clinical signs were not compatible with atopic dermatitis caused by this pollen. Results of hematological examination, serum chemistry and thyroid gland profile were normal. Examination of skin biopsy exhibited hyperplastic superficial perivascular dermatosis with severe acanthosis, excessive keratinocyte mitoses, patchy or diffuse mild spongiosis, and lymphocytic exocytosis in epidermis. Perivascular to interstitial mononuclear cells infiltration was seen in the superficial dermis. Based on the results of examination described above, epidermal dysplasia was diagnosed. Treatments with administration of antibiotics, etretinate, and prednisolone orally combined with topical ketoconazole cream and antiseborreic shampoos had no good results. Following treatment with long-term oral itraconazole at 10 mg/kg daily and chlorhexidine shampoos was successful. However, when itraconazole therapy was stopped, the condition worsened twice within 2 or 3 months. Readministration of itraconazole produced improvement within 4 weeks. This dog has now been controlled periodical itraconazole therapy.

• The Korean Journal of Physiology and Pharmacology
• /
• v.2 no.1
• /
• pp.95-100
• /
• 1998

The conductance change evoked by step depolarization was studied in primarily cultured rat adrenal chromaffin cells using patch-clamp and capacitance measurement techniques. When we applied a depolarizing pulse to a chromaffin cell, the inward calcium current was followed by an outward current and depolarization-induced exocytosis was accompanied by an increase in conductance trace. The slow inward tail current which has the same time course as the conductance change was observed in current recording. The activation of slow tail current was calcium-dependent. Reversal potentials agreed with Nernst equation assuming relative permeability of $Cs^+\;to\;K^+$ is 0.095. The outward current and tail current were blocked by apamin (200 nM) and d-tubocurarine (2 mM). The conductance change was blocked by apamin and did not affect membrane capacitance recording. We confirmed that conductance change after depolarization comes from the activation of the SK channel and can be blocked by application of the SK channel blockers. Consequently, it is necessary to consider blocking of the SK channel during membrane capacitance recording.

• Proceedings of the KOSOMBE Conference
• /
• v.1994 no.05
• /
• pp.142-145
• /
• 1994

Calcium(Ca) ion plays an important role to trigger the secretion of important neurotransmitters. Since Ca ion flows into the cell thru the ion selective channel, the conductance of which depends on the transmembrane potential, the voltage-dependent characteristic of Ca ion channel is crucial to elucidate the stimulus-secretion coupling of exocytosis. The present study measured the Ca ion currents thru a whole-cell configuration patch at the transmembrane potential clamped at various desired levels in the rat chromaffin cell. The resultant current-voltage relationship was differentiated to obtain dynamic conductance at each clamped voltage. Based on these measured data, five numerical parameters were extracted to reveal electrical properties of Ca ion inflow process thru the voltage-gated channel. The present study can be applied to comparing the electrical characteristics of Ca channel under different experimental conditions. Also, further study is warranted to model the conformational changes of the channel molecules.

• Preventive Nutrition and Food Science
• /
• v.22 no.1
• /
• pp.1-8
• /
• 2017

About 20 chemical elements are nutritionally essential for humans with defined molecular functions. Several essential and nonessential biometals are either functional nutrients with antidiabetic actions or can be diabetogenic. A key question remains whether changes in the metabolism of biometals and biominerals are a consequence of diabetes or are involved in its etiology. Exploration of the roles of zinc (Zn) in this regard is most revealing because 80 years of scientific discoveries link zinc and diabetes. In pancreatic ${\beta}$- and ${\alpha}$-cells, zinc has specific functions in the biochemistry of insulin and glucagon. When zinc ions are secreted during vesicular exocytosis, they have autocrine, paracrine, and endocrine roles. The membrane protein ZnT8 transports zinc ions into the insulin and glucagon granules. ZnT8 has a risk allele that predisposes the majority of humans to developing diabetes. In target tissues, increased availability of zinc enhances the insulin response by inhibiting protein tyrosine phosphatase 1B, which controls the phosphorylation state of the insulin receptor and hence downstream signalling. Inherited diseases of zinc metabolism, environmental exposures that interfere with the control of cellular zinc homeostasis, and nutritional or conditioned zinc deficiency influence the pathobiochemistry of diabetes. Accepting the view that zinc is one of the many factors in multiple gene-environment interactions that cause the functional demise of ${\beta}$-cells generates an immense potential for treating and perhaps preventing diabetes. Personalized nutrition, bioactive food, and pharmaceuticals targeting the control of cellular zinc in precision medicine are among the possible interventions.