• 약학회지
• /
• 제28권3호
• /
• pp.129-138
• /
• 1984

Specific [$^{3}H$] ouabain binding and $Ca^{2+}$ -uptake were measured to elucidate the role of high affinity [$^{3}H$] ouabain binding site in rat cardiac myocytes which contain 65% of rod cells. High affinity [$^{3}$H] ouabain binding site, which is about 3% of total pump sites, with apparent dissociation constant ($K_{D}$) of $1.1{\times}10^{-7}M$ and maximum binding site concentration (Bmax) of 1.2 pmol/mg protein ($1.754{\times}10^{5}cells$) were identified. At the concentration of $10^{-7}M$ to $10^{-4}M$, ouabain produced concentration dependent increase in $Ca^{2+}$-uptake of myocytes. The effect of ouabain on $Ca^{2+}$-uptake was not effected by membrane depolarization (elevated K+ in incubation medium) or verapamil. These results suggest that in rat ventricular myocytes the ouabain receptor complex to high affinity site may increase Na+ - $Ca^{2+}$ exchange across the sarcolemmal membrane by inhibition of Na+, K+ - ATPase.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.101.2-102
• /
• 2003

Baicalein (5,6,7-trihydroxyflavone), a flavonoid originated from the root of Chinese medicinal herb Scutellaria baicalensis, has been shown to exert anti-inflammatory and antioxidant effects and hepatic stellate cells play an important role in the pathogenesis or hepatic fibrosis. In this study, we investigated apoptosis stimulation by baicalein in activated rat hepatic stellate cells (T-HSC/C1-6). Transformed rat hepatic stellate cells (T-HSC/C1-6) were treated with baicalein(100uM, 70uM, 40uM). Apoptosis was determined by detection of DNA fragmentation in gel electrophoresis, morphological alternations by flow cytometry and quantification of phosphatidylserine externalization by Annexin V labeling. (omitted)

• Biomolecules & Therapeutics
• /
• 제13권1호
• /
• pp.48-58
• /
• 2005

The present study was conducted to investigate the effects of nicorandil on arterial blood pressure and vascular contractile responses in the normotensive anesthetized rats and to establish the mechanism of action. Nicorandil (30~300 ${\mu}g/kg$) given into a femoral vein of the normotensive anesthetized rat produced a dose-dependent depressor response. These nicorandil-induced hypotensive responses were not affected by pretreatment with atropine (3.0 mg/kg, i.v.) or propranolol (2.0 mg/kg, i.v.), while markedly inhibited in the presence of chlorisondamine (1.0 mg/kg, i.v.) or phentolamine (2.0 mg/kg, i.v.). Futhermore, after the pretreatment with 4-aminopyridine (1.0 mg/kg/30 min, i.v.) or glibenclamide (50.0 ${\mu}g/kg$/30min) into a femoral vein made a significant reproduction in pressor responses induced by intravenous norepinephrine. In he isolated rat aortic strips, both phenylephrine (10$^{-5}$ M)- and high potassium (5.6 ${\times}\;10^{-2}$ M)-inducedcontractile responses were dose-dependently depressed in the presence of nicorandil (25~100 ${\mu}M$). Collectively, these experimental results demonstrate that intravenous nicorandil causes a dose-dependent depressor action in the anesthetized rat at least partly through the blockade of vascular adrenergic ${\alpha}_1$-receptors, in addition to the well-known mechanism of potassium channel opening-induced vasorelaxation.

• The Korean Journal of Physiology and Pharmacology
• /
• 제1권3호
• /
• pp.297-302
• /
• 1997

Higenamine was widely used as traditional remedy for the treatment of rhumatoid arthritis. Nitric oxide(NO) may be a critical mediator in this inflammatory disease. Synovial tissue from humans with inflammatory arthritis expresses NOS2(iNOS) mRNA and protein, and generates NO in vitro. We therefore, investigated the effect of higenamine on the induction of nitric oxide synthase(NOS) promoted by lipopolysaccharide(LPS). Prophylactic application of higenamine selectively prevented LPS-primed initiation of L-arginine-induced relaxation and restored rhenylephrine(PE)-induced contraction in rat aorta. LPS-stimulated nitrite production in the incubation medium was reduced by higenamine. Furthermore, RT-PCR and Northern analysis indicated that higenamine reduced iNOS expression primed by LPS in rat aorta. These results suggest that higenamine prevents LPS-promoted induction of NOS in vascular smooth muscle.

• 한국가축번식학회지
• /
• 제22권2호
• /
• pp.127-136
• /
• 1998

A chimeric gene comprising murine whey acidic protein(mWAP) and human growth hormone(hGH) was used to produce transgenic rats express hGH and secrete it into the blood. Two lines of transgenic rats carrying the mWAP/hGH construct were established; High line was characterized by relatively high levels of serum hGH, and low line had relatively low levels. The secretory profiles of rat GH(rGH) as well as hGH, the transgene product, were obtained in transgenic males and females of low line; both hGH and rGH serum levels were flattened with no episodic fluctuations, and the overall mean concentration of rGH was significantly lower than in normal littermates. Although the animals of High line showed an acceles, as assessed by vaginal opening and occurrence of first ovulation, advanced by 7∼8 days in both lines of animals. Accordingly, the body weight at puberty of low line transgenic females was much lower than that of normal littermates, indicating that continuous hGH expression could induce precocious puberty without enhancing the growth rate.

• 약학회지
• /
• 제43권3호
• /
• pp.300-305
• /
• 1999

A sensitive and efficient assay method was applied to determine the level of glutamic acid (GA) and ${\gamma}-aminobutyric$ acid (GABA) in frontal cortex and hippocampus of rat administrated with ethanol and drugs. The compounds were derivatized with ο-phthalaldehyde (OPA) and 2-mercaptoethanof for precolunm analysis. The condition for the simultaneous determination of GA, GABA and $\beta-aminobutyric$ acid (BABA) by high performance liquid chromatography with electrochemical detection was reverse phase $C_{18}$ column as stationary phase, 0.1 M phosphate buffer containing 0.1 mM $Na_4EDTA$ : methanol = 55:45 (v+v) pH 3.8 as mobile phase and 0.7V electrode voltage. The stability of reaction product of GA, GABA and BABA with OPA could be increased by adding the same volume of polyethylene glycol 400 to reaction mixture. The GABA level in frotal cortex of rat was significantly decreased by the administration of picrotoxin and diazepam, but it was significantly increased by the administration of red ginseng total saponin, N-methyl-D-glucamine and (-)-deprenyl.

• 식품기술
• /
• 제12권2호
• /
• pp.26-38
• /
• 1999

조리가공 중 생성되는 주요 발암성 이환방향족아민(heterocyclic aromatic amine)인 Trp-P-1 및 Trp-P-2가 human 및 rat keratinocytes에 대해 나타내는 세포 독성을 colony expansion법의 의해 조사, 비교하였다. 특히 Trp-P-2는 human keratinocytes에 대해서는 독성을 나타내지 않은데 반해 rat keratinocytes(계대수 2-5)에 대해서는 독성을 나타내는 선택성을 나타내었다. 이러한 Trp-P-2의 종(species)간 독성감수성 차이가 대사 효소계 활성이나 mutagenic activation상의 차이에 기인되는지를 살펴본 결과, CYP4501As 및 독성감수성 차이가 크게 나타났던 human 및 rat keratinocytes의 microsome에서 거의 같았다. 이와 같은 결과는 CYP4501A1 및 CYP1B1의 mRNA의 발현정도를 northernblot에 의해 살펴보았던 결과에서도 일치하였다. 반면 Trp-P-2의 대사활성화 및 해독화에 관여하는 효소인 N.O-acetyltransferase(NAT)활성은 rat keratinocytes보다 human keratinocytes에서 높았다. 일반적으로 독성물질의 해독화에 관여하는 glutathione S-transferase(GST) 또한 rat keratinocytes보다 human keratinocytes에서 높게 나타났다. Trp-P-2가 mutagenic metabolite로 활성화되는 정도를 salmonella microsome microsuspension assay로 살펴본 결과, 독성 감수성 차이가 크게 나타났던 human 및 rat keratinocytes간의 활성은 비슷한 것으로 나타났다. DNA 및 단백질 adduct형성능의 경우, human 및 rat keratinocytes간 DNA adduct형성능에는 차이가 없었고, 단백질 adduct형성능의 경우만 Trp-P-2에 대한 독성감수성 정도가 컸던 rat keratinocytes가 다른 세포들에 비해 크게 나타났다. 이상의 결과를 종합해 볼 때, CYP1A- 또는 CYP1B1-관련 마이크로솜 효소활성이나 mutagenic activation은 human 및 rat keratinocytes간에 나타났던 독성 감수성의 차이를 설명할 수 없으며, 해독화에 관여하는 효소활성이 종간 관찰되었던 독성 감수성의 차이에 더 중요한 역할을 하는 것으로 보인다.

• 대한수의학회지
• /
• 제35권1호
• /
• pp.29-37
• /
• 1995

This study was carried out to investigate the morphological changes of the oxytocin secreting neurons in age-related rat hypothalamus by means of immunohistochemistry. The experimental group was 20 aged female rats (Sprague-Dawley, 25~30 months), and the control group was 10 adult female rats (10 months). All animals were perfused transcardially with 4% paraformaldehyde-lysine-periocdate(PLP), and serial transverse brain sections($30{\mu}m$) were prepared by means of cryotome, and were stained with rabbit anti-oxytocin antisera immunohistochemically, using the free floating method and avidin-viotin peroxidase complex. The results were as followings. 1. The immunostained oxytocin secreting neurons were located at the paraventricular nucleus and supraoptic nucleus of age-related rat hypothalamus chiefly. 2. The numbers of oxytocin secreting neurons decreased at the paraventricular nucleus and supraoptic nucleus of age-related rat hypothalamus(p<0.01) 3. The oxytocin secreting neurons of age-related rat hypothalamus immunostained less than those of the adult rat hypothalamus, and the paraventricular nucleus immunostained greater than supraoptic nucleus in age-related rat. 4. The numbers and expansion of dendrite and axonal varicosities decreased in the age-related rat hypothalamus greatly.

• Advances in Traditional Medicine
• /
• 제2권2호
• /
• pp.87-93
• /
• 2002

The present study was aimed to examine the role of endothelium in the relaxant effect of hawthorn fruit extract of Crataegus pinnatifida in four different types of rat arteries, posterior cerebral communicating artery, right descending coronary artery, common carotid artery, and aorta. In $9,11-dideoxy-11{\alpha}$, $9{\alpha}-epoxy-methanoprostaglandin$ $F_{2{\alpha}}$ (U46619)-preconstricted arterial rings except for aorta, the extract produced endothelium-independent relaxations with similar potency. This relaxation was unaffected by pretreatment with $100\;{\mu}M\;N^G-nitro-L-arginine$ methylester (L-NAME, the nitric oxide synthase inhibitor), $3\;{\mu}M$ 1H-[l,2,4]oxadiazolo$[4,2-{\alpha}]$quinoxalin-1-one (ODQ, the guanylate cyclase inhibitor), or $10\;{\mu}M$ indomethacin (the cyclooxygenase inhibitor). Putative $K^+$ channel blockers (charybdotoxin plus apamin or glibenclamide) did not affect the extract-induced relaxation in cerebral or coronary artery rings. In contrast, in rat aortic rings the extract produced significantly smaller relaxant response in endothelium-denuded rings than that in endothelium-intact rings. Pretreatment with L-NAME or ODQ abolished the extractinduced endothelium-dependent aortic relaxation, whilst indomethacin $(3\;{\mu}M)$ had no effect. The present results indicate that hawthorn fruit extract possesses a vasorelaxing effect in cerebral, coronary and carotid arteries and this effect is independent of the presence of a functional endothelium. However, the extract-induced endothelium-dependent relaxation in rat aorta was mediated through endothelial nitric oxide and cyclic GMP-dependent mechanisms, suggesting that active components in the extract may act on endothelium to stimulate release of nitric oxide in large conduit arteries of the rats.

• Journal of Periodontal and Implant Science
• /
• 제34권2호
• /
• pp.357-366
• /
• 2004

Chronic exposure to high levels of manganese leads a pronounce and debilitating disorder known as manganism. Research on the toxic manifestation of manganese have focused primarily on its neurological effects because exposure to high levels of the metal produces a distinct and irreversible extrapyramidal dysfunction resembling the dystonic movements associated with Parkinson's physiological and biochemical systems in the body. The purpose of this study was to evaluate the effect of manganeses on primary rat calvarial cell growth and toxicity. The experimental groups were in concentration of 0, 10, 30, 60, 100, 300 ${\mu}M$. Cell activity was assessed at day 1 and day 3 using a fluorescent molecular probe. Cell proliferation was evaluated at day 1 and day 3 by MTT assay. The amount of total protein synthesis was measured at day 3 and day 7. The results were as follows: The proliferation of primary rat calvarial cells were inhibited by $MnCl_2$ in the concentration exceeding $100{\mu}M$. The primary rat calvarial cells treated with $MnCl_2$ showed similar protein synthesis to the control group except in 100 ${\mu}M$. These result suggest that manganese suppress the viability and protein synthesis of primary rat calvarial cells in concentration exceeding $100{\mu}M$.