• Title/Summary/Keyword: Hyperemia

Search Result 123, Processing Time 0.025 seconds

Substrate-Perfusion Studies on Coronary Circulation and Myocardial Energy Metabolism in Spontaneously Hypertensive Rat Hearts (발현성 고혈압쥐의 관상순환 기능과 심장근의 에너지 대사에 관한 생체외 에너지원의 관류 연구)

  • 김은지
    • Journal of Nutrition and Health
    • /
    • v.28 no.2
    • /
    • pp.115-126
    • /
    • 1995
  • The effects of energy-yielding substrates on coronary circulation, myocardial oxygen metabolism, and intramyocytic adenylates of perfused Wistar control rat(WC) and spontaneously hypertensive rat(SHR) hearts were examined under basal and $\beta$-adrenergic stimulation conditions. The perfusion medium (1.0mM Ca2+) contained 5mM glucose (+5U/l insulin) in combination with 5mM pyruvate, 5mM lacate, 5mM acetate, or 5mM octanoate as energy substrates. Hearts were perfused with each substrate buffer for 20min under basal conditions. Coronary functinal hyperemia was induced by infusing for 20min isoproterenol (ISO, 1uM), a $\beta$-receptor agonist. Cardiac adenylates, glycolytic intermediates, and coronary venous lactate were measured by using an enzymatic analysis technique. Under basal conditions, acetate and octanoate significantly increased coronary flow(CF) of WC in parallel with myocardial oxygen consumption. However, CF of SHR was partly attenuated by coronary vasoconstriction despite metabolic acidosis. In addition, pyruvate and lactate depressd ISO-induced coronary functional hyperemia in SHR. It should be noted that octanoate exhibited coronary dysfunction under ISO conditions. On the other hand, fat substrates depleted myocardial high energy phosphate pool and accumulated breakdown intermediates. In SHR with coronary vasoconstriction under basal conditions, and with depressed coronary functional hyperemia, high energy phosphates were greatly depleted. These results suggest that energy substrates in the myocardium and coronary smooth muscle alter remarkably coronary circulation, and that coronary circulatory function is associated with a reserve of high energy phosphates and a balance between breakdown and nono synthesis of energy phosphates. These findings could be explained by alterations in the cytosolic redox state manipulated by LDH and hence in the cytosolic phosphorylation potential, which might be involved in hypertension of SHR.

  • PDF

Myocardial Function and Metabolic Energetics in Low Flow Ischemia and with $\beta$-Adrenergic Stimulation in Spontaneously Hypertensive Rat Hearts

  • Kang, Young-Hee;Kang, Jung-Sook;Park, Han-Yoon
    • Preventive Nutrition and Food Science
    • /
    • v.6 no.1
    • /
    • pp.43-50
    • /
    • 2001
  • The effects of cardiac ischemia-reperfusion and $\beta$-adrenergic stimulation on metabolic function and energetics were investigated in Lan gendorff-perfused spontaneously hypertensive rat (SHR) hearts. Sarcoplasmic reticulum {TEX}$Ca^{2+}${/TEX}-dependent ATPase and cardiac lactate dehydrogenase (LDH) are additionally studied. The perfusion medium (1.0 mM {TEX}$Ca^{2+}${/TEX}) contained 5 mM glucose(+5 U/L insulin) and 2 mM pyruvate as substrates. Global ischemia was induced by reducing perfusion pressure of 100 to 40 cm {TEX}$H_{2}${/TEX}O, followed by 20 min reperfusin. Isoproterenol (ISO, 1$\mu$M) was infused for 10 min. Coronary vascular resistance and myocardial oxygen consumption ({TEX}$MVO_{2}${/TEX}) of SHR were increased in parallel with enhanced venous lactate during ischemia and reperfusion compared to those of Sprague Dawley (SD) hearts. Although ischemia-induced increase in venous lactate and combined adenosine plus inosine was abolished, coronary vasodilation produced in SD during reperfusion. In SHR, depressed reactive hyperemia was associated with a fall in cardiac ATP and CrP/Pi ratio and a rise in intracellular lactate/Pyruvate ratio. On the other hand, ISO produced coronary functional hyperemia and an increase in {TEX}$MVO_{2}${/TEX}. However, these responses were less than those in SHR hearts. The ATPase activity of SHR was attenuated in free {TEX}$Ca^{2+}${/TEX} concentrations used under basal condition and with ISO compared to that of SD. Venous lactate output and cardiac LDH activity were augmented in SHR as influenced by ISO. These results demonstrate that coronary reactive and functional hyperemia was dpressed in SHR, which cold be explained by alterations in the cytosolic phosphorylation potential and the cytosolic redox state manipulated by LDH, and by abnormal free calcium handling.

  • PDF

Histopathological Observations on the Renal Injury in Rats Administered with Enrofloxacin and Oxalate (Oxalate와 Enrofloxacin 투여한 랫트신장에 대한 병리조직학적관찰)

  • 오원석;이차수;오규실;정원일;정재용;정다히;정규식
    • Journal of Veterinary Clinics
    • /
    • v.20 no.4
    • /
    • pp.449-457
    • /
    • 2003
  • To investigate the renal effects of enrofloxacin administration on rats induced with dehydration or hyperoxaluria, male rats were treated with enrofloxacin of 50 mg to 500 mg/kg b.w.. The microscopical observations of kidney and urine sediment were carried out in the experimental groups. The result obtained were as follows; The male rats deprived of water for 72 hours and administered with enrofloxacin. As enrofloxacin administration dose was increased, clinical signs such as loss of appetite, depression, weakness, and loss of urine output became more severe. In the histopathological findings, there were hyperemia and hemorrhage in renal cortex, vacuolation and necrosis of renal tubular epithelia, proteinous casts within renal tubules. The male rats were orally administered with sodium oxalate and injected with enrofloxacin for 7days. As enrofloxacin administration dose was increased, clinical signs such as the loss of appetite and water consumption, and weakness became more severe. In the histopathological findings, there are hemorrhage of glomeruli and cortical hyperemia, vacuolation and necrosis of tubular epithelia, proteinous casts in renal tubules. In the microscopical findings of urine sediment, there are calcium oxalate crystal (diamond-like type) and magnesium ammonium phosphate crystals (rhomboid). The male rats were intraperitoneally injected with sodium oxalate and administered with enrofloxacin for 7days. As enrofloxacin administration dose was increased, clinical signs such as the loss of appetite and water consumption, weakness were more severe. In the histopathological findings, there were hyperemia and hemorrhage in both glomeruli and renal cortex. Severe necrosis of renal tubular epithelia, bluish materials within renal tubules were also found. In the microscopical findings of urine sediment, there were many calcium oxalate crystals. The present results suggest that enrofloxacin has some injurious effects in rats having dehydration or hyperoxaluria, and clinically, we should consider these renal injury effects when we use enrofloxacin in patients accompanied renal disease, dehydration and hyperoxaluria conditions.

Role of Inflammation in Carcinogenesis (발암과정에서 염증의 역할)

  • 이병무;이지은;김태정;조홍태
    • Toxicological Research
    • /
    • v.13 no.1_2
    • /
    • pp.1-21
    • /
    • 1997
  • 염증반응이란 우리 신체에 외부 물질이 침입했을 경우 대처하는 정상적인 현상이다. 외부에서 물리, 화학, 생물학적 물질에 노출되었을 경우 혈관이 팽창하고, 비특이적 면역반응이 시작된다. Selectin, integrin, immunoglobulin superfamily와 같은 adhesion molecule에 의해 macrophage 및 neutrophil과 같은 leukocyte의 반응을 촉진하기 위해 exudation이 일어나고 침입 부위에 모여 hyperemia가 발생된다.(Govan 등, 1995)

  • PDF

A Novel Approach of Drug Delivery via Intrascleral Implantation of Latanoprost Imbedded Disk

  • Moon, Soo-Jin;Seo, Min-Soo;Kang, Kyung-Ku;Sung, Soo-Eun;Yun, Sungho;Kwon, Young-Sam
    • Journal of Veterinary Clinics
    • /
    • v.36 no.4
    • /
    • pp.212-218
    • /
    • 2019
  • This study evaluates the drug delivery and biocompatibility of latanoprost imbedded disk in rabbit eye by assessing pharmacokinetics (PK), clinical signs, and histopathologic findings. During 84 days of experimental period, 48 New Zealand Rabbit (NZW) eyes were divided into control group which received no treatment and test material group which latanoprost were implanted intrasclerally. Pharmacokinetic assessment was performed to evaluate the drug delivery for 3 months. For biocompatibility, clinical signs were observed and histopathological analysis was done at 3 months post-operatively. The concentration of latanoprost in the iris tissue was maintained during the experimental period and the highest level of latanoprost was found at 4 weeks. However, the latanoprost was not found in the aqueous humor. Macroscopically, there was no evidence of clinical signs except for temporary hyperemia, neovascularization and edema immediately after surgery. On histopathological examination, there were no abnormal findings such as hyperemia, neovascularization, and edema in the eye tissues. The latanoprost imbedded disks has effectively released the drug into the adjacent tissue with high compatibility. Therefore, this study suggests that the drug delivery system with intrascleral latanoprost imbedded implants might be a novel approach as a treatment option for glaucoma.

Studies of Alterations in Spleno-Hepatic Reflex in Portal Hypertensive Cats (간문맥 고혈압 고양이에서 비-간 교감신경성 반사의 변동에 대한 연구)

  • Song, Hwan-Kyu;Rhim, Byung-Yong;Kim, Chi-Dae;Hong, Ki-Whan
    • The Korean Journal of Pharmacology
    • /
    • v.23 no.1
    • /
    • pp.15-23
    • /
    • 1987
  • To elucidate the mechanism of splanchnic hyperemia associated with chronic portal hypertension, we have investigated the alteration in visceral reflexes in conjuction with circulatory hemodynamics in portal ligated portal hypertension in cats. When capsaicin, bradykinin and vasopressin were injected via splenic artery of sham cat, respectively, they caused not only reflex excitation of systemic arterial pressure, but also elevation of splenic venous pressure with unchanged heart rates. Simultaneously, they evoked the sympathetic efferent excitation of liver (spleno-hepatic reflex) as well as of spleen (spleno-splenic reflex). Similarly, capsaicin upon pledging on the liver surface evoked a significant increase in the pressor reflex with hepatic nerve excitation (hepato-hepatic reflex). After portal ligation, the splenic venous pressure was gradually elevated in association with decrease in systemic arterial pressure. However, the excitation of pressor reflex was enhanced on the and day, thereafter, being returned to the control, and the reflexly induced spleno-splenic, spleno-hepatic and hepato-hepatic sympathetic excitations were significantly diminished on the 8th day following portal vein ligation. In conclusion, it is suggested that sympathetic reflexes to spleen and liver are specifically intervened by the same central pathways and furthermore, the diminution of these viscero-visceral reflex excitations after portal ligation may be related to the intestinal hyperemia.

  • PDF

개방와동에서 상아질과 치수의 조직변화에 관한 연구

  • Kim, In-Chul;Park, Moon-Shik
    • The Journal of the Korean dental association
    • /
    • v.12 no.3
    • /
    • pp.195-198
    • /
    • 1974
  • The purpose of this study is to obtain the histopathological change of dentin and pulp when the prepared cavity is exposed to oral fluid without protection. The results were as follows: 1. Hyperemia of pulp blood vessel and round cell infiltration in odontoblast layer observed on the one week experimental dogs. 2. Marked edematous change, round cell infiltration, fibrotic change and prolif eration of collagenous fiber showed on the 8 week experimental dogs. 3. Prepared cavity should be protected by the biologically accepted lining mater ials regardless of cavity depth.

  • PDF

Study of single dose test of Sweet Bee Venom in rats (Sweet BV의 rat를 이용한 단회 근육시술 독성시험)

  • Kim, Young-Jin;Lim, Chung-San;Kwon, Ki-Rok
    • Journal of Pharmacopuncture
    • /
    • v.12 no.4
    • /
    • pp.5-32
    • /
    • 2009
  • Objectives: This study was performed to analyse single dose toxicity of pure melittin(Sweet Bee Venom-Sweet BV) extracted from the bee venom by utilizing protein isolation method of gel filtration. Methods: All experiments were conducted at Biotoxtech, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Six weeks old female Sprague-Dawley rats were chosen for the pilot study and determined 30㎎/㎏ which is 4285 times higher than the clinical application dosage as the high dosage, followed by 15 and 7.5㎎/㎏ as mid and lose dosage, respectively. Equal amount of excipient to the Sweet BV experiment groups was administered as the control group. Results: 1. No mortality was witnessed in all of the experiment groups. 2. Hyperemia and movement disorder were observed around the area of administration in all groups, and higher occurrence in the higher dosage groups. Hyperemia and movement disorder diminished with elapsed time. 3. For the weight measurement, male groups showed larger reduction in weight in accordance with higher dosage. Female groups didn't s how significant changes. 4. To verify abnormalities of organs and tissues, cerebellum, cerebrum, liver, lung, kidney, and spinal nerves were removed and conducted histological observation with H-E staining. No abnormalities were detected in any of organs and tissues. 5. One female rat in the 30㎎/㎏ group had amputated toe near the administered area and histopathological finding was hemorrhage with inflammation. This is presumed as a secondary infection after the administration of Sweet BV. Conclusion: Above findings suggest Sweet BV is relatively s safe treatment medium. Further studies on the subject should be conducted to yield more concrete evidences.

Effects of Hyperemia Menu Types and Metacognition on Errors at Learning stages and Achievement (하이퍼미디어 메뉴방식과 메타인지가 학습시기에 따른 오류와 성취도에 미치는 효과)

  • Kim, Jeong-Rang;Park, Seon-Ju;Kim, Byeong-Gi
    • The Transactions of the Korea Information Processing Society
    • /
    • v.3 no.5
    • /
    • pp.1059-1069
    • /
    • 1996
  • The purpose of this paper is to examine some effects of four menu types: icon menu, context menu, pulldown menu, and bar selection menu. In order to find whether there are some effects of menu types or learning stages (the first, intermediate and the last stage) on skill-based errors, each of the menus has been studied in relation to hyperemia instruction, menu search time, scholastic a chievements and learners' metacognitionon their errors. A further purpose of this paper is to suggest some strategies for enabling learner to select menus more efficiently in order to enhance the learner's own learning effectiveness in hypere mia instruction.The results of this study are as follows. The menu types had a significant effect on the low metacognition regulation group. The context menu types had a significant effect on achievements. In contrast, it was also noticed he the menu types did not have any significant effect on the high metacognition regulation group. The bar-selection menu type and the icon menu type had a relatively significant effect on skill-based errors in the first stage of learning.

  • PDF

Toxicity of Bis(tri-n-butyltin)oxide (TBTO) on the Organ Structure of the Flounder, Paralichthys olivaceus (넙치(Paralichthys olivaceus)의 기관계 구조에 미치는 bis(tri-n-butyltin)oxide (TBTO) 독성)

  • 이정식;강주찬;신윤경;진영국;박정준
    • Korean Journal of Environmental Biology
    • /
    • v.22 no.1
    • /
    • pp.133-140
    • /
    • 2004
  • The histopathologieal effects of his(tri-n-butyltin)oxide (TBTO) on the flounder, Paralichthys otivaceus were examined by means of histological methods. The experimental fishes were exposed to 0.17, 0.36, 0.60, 3.20, 6.30, 12.50 ${\mu}g \;L^{-1}$TBTO concentrations for 42 days. Histopathological change of the fish exposed to TBTO is dependent on the exposure duration and concentration. In the lower concentrations early histological changes included activated mucous cells and chloride cells, capillary hyperemia and epithelial hyperplasia in the gill; hepatocyte activation, degeneration of bile duct and pancyeatic zymogen reduction in the hepatopancreas; and capillary hyperemia, appearance of eosinophilic cell and melano-macrophagocytes in the kidney. At the higher concentrations histological changes of dysfunctionality included epithelial lifting and deformation of the lamellae in the gill; pycnosis and cytoplasmic degeneration of hepatocyte; pycnosis of haemopoietic cell and deformation of renal tubules and glomerulus in the kidney. It is indicated that TBTO induced histopathological changes in the fish as other aquatic pollutants.