• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.2
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• pp.127-132
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• 1990

This research was performed to observe the effect on aggregation of rat platelet treated with ginkgo and perilla oil which contain much linolenic acid. The numbers of platelet treated with ginkgo and perilla oil were $2.7{\times}10^{8}/m{\ell}\;and\;4.7{\times}10^{8}/m{\ell}$, respectively. These numbers were much less than control group(this group was $7.5{\times}10^{8}/m{\ell}$). The ability of platelet aggregation treated with Perilla oil and ginkgo oil was 1.4 folds less than control group. Concentrations of total cholesterol and free fatty acid in serum of rat treated with ginkgo and perilla oil group were almost equal to those of control group. group.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.229-236
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• 2000

The synthesis of steroid hormone starts from cholesterol. Steroidogenic acute regulatory protein (StAR) acutely transfers cholesterol from the outer mitochondrial membrane to the inner in the early step of steroidogenesis. Many kinds of steroid hormone are mainly synthesized in adrenal grand, ovary, and testis. Among the steroid hormone, testosterone is synthesized in Leydig cells of the testis, the production of testosterone significantly increases in adult testis after puberty onset. Therefore, we think that the expression of StAR mRNA in testis will change according to the testicular development. The aim of this study is to determine the distribution of StAR mRNA in immature and adult rat testes and to confirm the functions of StAR in these testes. Thus, in situ hybridization was used in rat testes of the 2, 4, and 10 weeks of age. StAR mRNA was expressed in Leydig cells. Positive signals of StAR mRNA were weakly detected in Leydig cells of the 2 weeks of age. But, StAR mRNA was strongly expressed in Leydig cells of the 4 and 10 weeks of age, where steroidogenesis actively occur. In our results, the pattern of StAR mRNA expression was similar to the pattern of testosterone production in immature and adult rat testes. In conclusion, we can suggest that StAR acts as an important factor to regulate the synthesis of testosterone in Leydig cells of the rat testis.

• YAKHAK HOEJI
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• v.37 no.2
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• pp.163-171
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• 1993

In order to study the functions of vascular endothelial nitric oxide(NO) generating system, we examined the effects of monomethylarginine(MMA) and dimethylarginine(DMA)(asym., sym.), arginine analogues, on modulation of vascular tone. Also, the concentrations of endogenous arginie and MMA were measured by HPLC in rat aortic tissues. The results were as follows. 1. The maximum relaxation induced by Ach (1.5$\times$10$^{-6}$M) was 80% of the contractility of rings of rat aorta induced by phenylephrine and L-Arg causes endothelium-dependent relaxation of the aorta precontracted with phenylephrine and these relaxation were concentration-dependent. 2. Endothelium-dependent contractility of rings of rat aorta induced by MMA (100 $\mu{M}$), DMA (asym., 100 $\mu{M}$) and DMA (sym., 100 $\mu{M}$) were 25.5%, 27.5% and 16.5% of that induced by phenylephrine respectively. 3. The relaxation of rat aortic ring induced by L-Arg was inhibited by MMA, DMA(asym.) and DMA(sym.). The degrees of inhibition induced by MMA, DMA(asym.) and DMA(sym.) were 45.7%, 37.1% and 18.3%, respectively. 4. The endogenous arginine and monomethylarginine contents in rat aorta were 83 pmoles/mg wet tissue, and 34.9 pmoles/mg wet tissue. After stimulation with Ach, the concentrations of L-Arg and MMA were significantly decreased. These results suggest that there are the strong relationships between the endogenous L-Arg and methylated arginines and NO-generating system.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.253-259
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• 1998

In this study, we developed immunoassay methods for the more convenient and effective detection of rat tracheal mucin and the results were compared with those of [$3^H$]glucosamine based gel-filtratioh method. A monoclonal anti-rat tracheal mucin antibody, mAbRT03, which specifically recognizes rat tracheal mucins, was used throughout in this study. To induce mucin secretion, varying concentrations of ATP (0-2 mM) were applied to the primary rat tracheal surface epithelial (RTSE) cell culture which had been metabolically radiolabeled with [$3^H$]glucosamine and the secretion of mucin was analyzed both by the immunoassay and the gel-filtration chromatography methods. For the immunoassay, the following two procedures were employed. 1) Simple ELISA; the culture spent media were directly coated onto the assay plate and the immunoreactivity with mAbRT03 was assessed from the standard curve generated with the purified rat mucin. 2) Inhibition ELISA; A known amount of the purified rat mucin was coated onto the assay plate and then ATP-stimulated culture spent media were added to inhibit the immunorelitivity with mAbRT03. The contents of mucin in the sample were calculated from the standard inhibition curve which was generated with the purified rat mucin. The assay results obtained from the immunoassays were identical with those from the gel-filtration methods. The present result indicates that ELISA can be substituted for the laborious, time-consuming gel-filtration assay in studying the regulation of airway mucin release from cultured airway epithelial cells.

• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.83-87
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• 1996

The objective of this study is to investigate the direct effects of green tea catechins(GTC) on vascular smooth muscle tension and 45Ca2+ Uptake in rat aorta. The methods used in this study are isometric tension measurements using physiograph, Lanthanum method for 45Ca2+(2 uCi/ml) uptake measurement in rat aorta. GTC modified tension induced by 40 mM KCl or 1 uM norepinephrine in rat aorta. Low concentrations of GTC(<0.5mg/ml) increased tension by 40 mM KCl or 1 uM norepinephrine, individually. However, high conecentration of GTC(>0.5 mg/ml) inhibiited tension by 40 mM KCl or 1 uM norepinephrine, individually. GTC increased 45Ca uptake induced by 40 mM KCl in a dose-dependent manner. From these results, GTC has the dual actions in vascular smooth muscle in vitro. Low concentrations of GTC augments tension by K or norepinephrine. However, high concentrations of GTC inhibits tension by K or norepinephrine GTC may have Ca2+ channel activation, action, which may result in unphysiological vasodilation by Ca2+ overload in vascular smooth muscle.

• IMMUNE NETWORK
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• v.2 no.4
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• pp.195-201
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• 2002

Background: IgE is closely related to the development of allergies. However, the poor relationship between the specific IgE level and the severity of allergic diseases suggests the possibility of functionally different IgE isoforms. With this in mind, rat basophilic leukemia (RBL)-2H3 activation was analyzed with each type of rat IgE for two parameters, exocytosis and IL-4 mRNA production. RBL-2H3 has been well documented in the rat mucosal mast cell line. Methods: RBL-2H3 cells sensitized with each kind of rat IgE was activated by cross-linking FcRI with B5 (monoclonal anti-rat IgE mouse IgG antibodies). The RBL-2H3 exocytosis was measured by analyzing the ${\beta}$-hexosaminidase level, and the level of IL-4 mRNA synthesis was analyzed using semiquantitative RT-PCR. Rat IgE, which was produced by a parasite infection (REP), was prepared using either Paragonimus westermani metacercariae (REP-PW) or Anisakis simplex third stage larvae (REP-AS). A rat IgE prototype of IR162 was prepared by a peritoneal injection of immunocytoma. Results: The level of exocytosis showed a linear relationship with the rat IgE concentration when REP-PW or REP-AS was applied. However, it exhibited a biphasic response with IR162. In addition, the time course of heating at $56^{\circ}C$ illustrated the similarity between REP-PW and REP-AS, which differed from that of IR162. In contrast, the level of IL-4 mRNA synthesis in the RBL-2H3 cells with IR162 was comparable to that of either REP-PW or REP-AS. Conclusion: These results suggest that functionally different rat IgE isoforms exists in RBL-2H3 exocytosis.

• Biomolecules & Therapeutics
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• v.15 no.2
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• pp.108-117
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• 2007

The aim of the present study was to investigate the effect of glibenclamide, a hypoglycemic sulfonylurea, which selectively blocks ATP-sensitive K$^+$ channels, on secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane depolarization from the isolated perfused rat adrenal glands. The perfusion of glibenclamide (1.0 mM) into an adrenal vein for 90 min produced time-dependently enhanced the CA secretory responses evoked by ACh (5.32 mM), high K$^+$ (a direct membrane depolarizer, 56 mM), DMPP (a selective neuronal nicotinic receptor agonist, 100 ${\mu}$M for 2 min), McN-A-343 (a selective muscarinic M1 receptor agonist, 100 ${\mu}$M for 2 min), Bay-K-8644 (an activator of L-type dihydropyridine Ca$^{2+}$ channels, 10 ${\mu}$M for 4 min) and cyclopiazonic acid (an activator of cytoplasmic Ca$^{2+}$-ATPase, 10 ${\mu}$M for 4 min). In adrenal glands simultaneously preloaded with glibenclamide (1.0 mM) and nicorandil (a selective opener of ATP-sensitive K$^+$ channels, 1.0 mM), the CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were recovered to the considerable extent of the control release in comparison with that of glibenclamide-treatment only. Taken together, the present study demonstrates that glibenclamide enhances the adrenal CA secretion in response to stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization from the isolated perfused rat adrenal glands. It seems that this facilitatory effect of glibenclamide may be mediated by enhancement of both Ca$^{2+}$ influx and the Ca$^{2+}$ release from intracellular store through the blockade of K$_{ATP}$ channels in the rat adrenomedullary chromaffin cells. These results suggest that glibenclamide-sensitive K$_{ATP}$ channels may play a regulatory role in the rat adrenomedullary CA secretion.

• Biomolecules & Therapeutics
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• v.3 no.2
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• pp.149-153
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• 1995

Nitric oxide (NO) has been regarded as one of the neurotransmitters of nonadrenergic, noncholinergic (NANC) nerve stimulation in rabbit corpus cavernosum, rat gastric fundus and human intestine. PIANO (photo-induced adequate nitric oxide) is a very useful tool to investige the role of NO in various smooth muscles where NO is a mediator. The present study was undertaken to compare the physiological responses of the rat gastric smooth muscle in response to NANC nerve stimulation and to PIANO. Photolysis of L-NAME, D-NAME and streptozotocin (572) by UV light in the bathing medium caused relaxation of rat gastric fungus that contracted with carbachol, but was resistant to tetrodotoxin (TTX, 1 $\mu$M). Electrical stimulation (20 V, 2~32 Hz, 0.2 msec, 10s) of the gastric fundus, in the presence of atropine and guanethidine, induced frequency-dependent, TTX-sensitive relaxation. Sodium nitroprusside (1 nM-10 $\mu$M), a NO donor, mimicked the relaxations observed after NANC-stimulation or PIANO. Furthermore, PIANO caused UV light exposure time-dependent increase of CGMP in rat gastric fungus strips. These results provide another evidence indirectly that NO is one of the mediators of the NANC inhibitory nerve stimulation in the rat gastric fundus.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.389-396
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• 2002

In the present work, we examined the mechanism of vasorelaxant effect of scopoletin, an active constituent of Artemisia capillaris on rat thoracic descending aortic rings. Scopoletin induced a concentration-dependent relaxation in rat thoracic descending aortic rings pre-contracted with phenylephrine (EC/sub 50/ = 238.94±37.4 μM), while it was less effective in rat thoracic descending aortic rings precontracted with high potassium solution (KCI 30 mM). Vasorelaxation by scopoletin was significantly inhibited after endothelial removal, but recovered at high concentration. Pretreatment of rat thoracic descending aortic rings with N/sup G/-nitro-L-arginine (100 μM), a nitric oxide synthase inhibitor, and atropine (1 μM), a muscarinic receptor antagonist, significantly inhibited scopoletin-induced relaxation of rat thoracic descending aortic rings. Neither indomethacin (3 μM), an inhibitor of cydooxygenase, nor propranolol (1 μM), a β -adrenoceptor antagonist, modified the effect of scopoletin. The combination of N/sup G/ -nitro-L-arginine (100 μ M) and miconazole (10 μ M), an inhibitor of cytochrome P 450, did not modify the effect of scopoletin, when compared with pretreatment with N/sup G/-nitro-L-arginine(100 μM) alone. Vasorelaxant effect of scopoletin was inverted by pretreatment with diltiazem (10 μM), a Ca/sup 2+/-channel blocker, at low concentration, while restored at high concentration. Apamin (K/sub ca/-channel blocker, 1 μM), 4-aminopyridine (4-AP, K/sub v/-channel blocker, 1 mM), and tetrodotoxin (TTX, Na/sup +/-channel blocker 1 μM) potentiated the vasorelaxant effect of scopoledn, but glibendamide (K/sub ATP/-channel blocker, 10 μM), tetraetylammonium(TEA, non-selective K-channel blocker, 10 mM) did not affect the relaxation of scopoletin. Free radical scavengers (TEMPO, catalase, mannitol) did not modify vascular tone. These results suggest that nitric oxide, Ca/sup 2+/ -channels play a role in endothelium-dependent relaxations to scopoletin in rat aortas, that apamin, 4-AP, TTX but not glibenclamide, TEA potentiated relaxation to scopoletin mediated by these channels, and that free radicals do not concern to the vasorelaxant effect of scopoletin.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.88-88
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• 1995

Tetrahydroisoquinoline (THI) compounds have various pharmacological actions in the cardiovascular system. Recently, we have synthesized 1-${\alpha}$-naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, YS 49. In the present study, we evaluated the effect of YS-49 on positive inotropic and chronotropic action using isolated rat heart and on blood pressure and heart rate using anesthesized rabbit. Vasodilating action was also assessed in isolated rat thoracic aorta. YS 49, concentration-dependently relaxed rat aorta precontracted with phenylephrine (PE, 0.3 ${\mu}$M) and high potassium (high K$\^$+/, 65.4 mM). The 50% inhibitory concentration (IC$\sub$50/) of YS 49 in PE-induced and high K$\^$+/-induded contraction was 5.36 ${\mu}$M and 2.52 ${\mu}$M, respectively. In isolated rat atria, YS 49 increased both heart rate and force, and in anesthesized rabbit it decreased blood pressure but increased heart rate. In addition, to know the mechanism of action of the compound, propranolol, nonselective ${\beta}$-antagonist, and phentolamine, ${\alpha}$-blocker, were used. Furthermore, a comparison with the effect of higenamine, trimetoquinol on the vasodilating action in rat thoracic aorta was also made. The action of YS 49 was inhibited by the presence of propranolo, not pentolamine. These results indicate that cardiotonic and vasodilatory action of YS 49 is attributable, at least in part, for ${\beta}$-receptor stimulation.