• The Korean Journal of Pharmacology
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• v.21 no.2
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• pp.119-127
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• 1985

The renal function is under regulatory influence of the central nervous system, mainly through activation of sympathetic nerve to the kidney, and it was recently reported that clonidine, an agonist to ${\alpha}_2$-adrenoceptors, induces diuresis and natriuresis when injected directly into a lateral ventricle of the rabbit brain (i.c.v.). This study was undertaken, therefore, to obtain further information as to the role of the central ${\alpha}_2$-adrenoceptors in regulating renal function, by observing the effects of i.c.v. yohimbine, a specific antagonist of adrenoceptors of ${\alpha}_2$-type, on the rabbit renal function, and to elucidate the mechanism involved in it. With 10 ${\mu}g/kg$ i.c.v. of yohimbine sodium excretion transiently increased along with increasing tendency of urine flow, renal plasma flow and glomerular filtration rate. These responses decreased with increasing doses. With 100 and 300 ${\mu}g/kg$ i.c.v. marked antidiuresis and antinatriuresis as well as profound decreases of renal perfusion and glomerular filtration were noted. Systemic blood pressure transiently increased. In reserpinized rabbits, 100 ${\mu}g/kg$ yohimbine i.c.v. did not produce any significant changes in urine flow, sodium excretion as well as in renal hemodynamics. The pressor response was also abolished. In preparations in which one kidney was denervated and the other left intact as control, i.c.v. yohimbine elicited typical antidiuretic antinatriuretic response in the innervated control kidney, whereas the denervated experimental kidney responded with marked diuresis and increases in excretory rates of sodium and potassium and in osmolar clearance in spite of absence of increased filtration and perfusion . Systemic blood pressure responded as in the normal rabbits. These observations indicate that i.c.v. yohimbine affects renal function in dual ways in opposite directions, the first being the antidiuretic antinatriuretic effects which results from decreased renal perfusion and glomerular filtration due to sympathetic activation and which is predominantly expressed in the normal rabbits, and the second less apparent effect being the diuretic and natriuretic action which is not mediated by nerve pathway but brought about by some humoral mechanism and which is effected by decreased sodium reabsorption in the tubules, possibly of the proximal portion.

• Korean Journal of Veterinary Research
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• v.2 no.1
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• pp.1-13
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• 1962

10두(頭)의 홀스타인 자우(仔牛)에 glucagon, insulin 등 홀몬과 reserpine 및 nicotine을 투여(投與)하여 그들이 췌장(膵臟)의 Langerhans 도서(島嶼)에 미치는 세포학적(細胞學的) 영향을 전자현미경(電子顯微鏡)에 의해서 연구하는 도중 거대(巨大)한 크기의 도서(島嶼)를 관찰하였다. 이 거대도서(巨大島嶼)들은 상기(上記)한 약품투여에 영향을 받지 않으며 거의 beta 세포(細胞)들로만 되어 있으므로 보통 크기의 도서(島嶼)들과의 혼동을 피하기 위하여서는 그 분포상태(分布狀態)와 세포학적(細胞學的) 및 조직학적(組織學的) 특징(特徵)을 구명(究明)하는 것이 필요하게 되어 본연구(本硏究)에 착수하였든 것이며 아울러 췌장(膵臟) 각부분(各部分)에 함유되는 Langerhans 도서수(島嶼數)의 평균치(平均値)를 산출(算出)하였다. Langerhans 도서(島嶼)는 편의상 그 크기에 따라서 직경(直徑) $200{\mu}$이하(以下)의 것을 "Regular islets" $200{\sim}500{\mu}$까지의 것을 "Intermediate islets" 그리고 $500{\mu}$ 이상(以上)의 것을 "Giant islets"라 이름지어서 구별하였다. 지금까지 알려진 최대(最大)의 도서(島嶼)는 개에서 관찰된 $333{\mu}$의 도서(島嶼)이었는데 필자는 본연구(本硏究)에서 직경 $1.395{\mu}$에 달하는 것과 기리 $2,700{\mu}$에 달하는 거대(巨大)한 도서(島嶼)들을 관찰하였다. 본연구(本硏究)의 결과(結果)를 요약(要約)하면 다음과 같다. 1. 자우췌장(仔牛膵腸) 50평방(平方)mm 면적(面積)내에 함유되는 Langerhans 도서(島嶼)의 수(數)는 평균(平均) 191개로서 다른 연구자에 의해서 보고된 수치(數値)보다 훨씬 많은 것이었다. 2. 거대도서(巨大島嶼)의 크기는 직경(直徑) $200{\sim}1,400{\mu}$이며 그 분포상태(分布狀態)는 보통 크기의 도서(島嶼)와 마찬가지로 췌장(膵臟)의 십이지장부(十二指腸部) 중간부(中間部) 및 췌장부(膵臟部)의 순서(順序)로 많이 함유되고 있다. 즉 십이지장부(十二指腸部)에는 2% 중간부(中間部) 1.8% 췌장부(膵臟部)에는 0.8%의 거대도서(巨大島嶼)가 함유되어 있으며 직경(直徑) $200{\mu}$이상(以上)의 도서평균치(島嶼平均値)는 1.53%이었다. 3. 중간대(中間大)의 도서(島嶼)와 거대도서(巨大島嶼)들은 거의 beta 세포(細胞)들로서만 되어있음으로 "중간대(中間大) beta 도서(島嶼)" 및 "거대(巨大) beta 도서(島嶼)"라고 각 각 명명하였으며 alpha세포(細胞)들이 있는 경우에는 작은 세포집합체(細胞集合體)를 이루고 도서전반(島嶼全般)에 걸쳐서 산재(散在)한다. 4. 췌장(膵臟)에 함유되고 있는 거대(巨大) beta 도서(島嶼)의 수(數)는 적지마는 보통 크기의 도서(島嶼)와 비교할때 그 용량(容量)은 막대한 것이며 따라서 insulin 분비량(分泌量)도 많을것이므로 우췌장(牛膵臟)의 insulin 분비(分泌)를 연구할 때에는 반듯이 이 사실(事實)을 고려해야 할 것이다. 5. 불규칙한 색상(索狀)의 실질세포(實質細胞)들로된 거대(巨大) beta 도서(島嶼)에는 간질결합조직(間質結合組織)이 풍부하며 그 간질(間質) 속에는 비교적 큰 혈관(血管)과 개재관양(介在管樣) 구조물(構造物)이 들어있다. 거대(巨大) beta 도서(島嶼)는 출생(出生)후 도서내외(島嶼內外)에 산재(散在)하고 있는 외분비도관세포(外分泌導管細胞)들의 증식(增殖)에 의해서 발생(發生)하며 그 크기도 증대(增大)하는 것으로 믿어진다. 6. 거대(巨大) beta 도서(島嶼)의 beta 세포(細胞)들은 현저한 Golgi 장치(裝置)와 비대(肥大)한 핵소체(核小體) 및 포상핵(胞狀核)등의 세포학적(細胞學的) 특징을 가지며 이것은 거대(巨大) beta 도서(島嶼)가 보통 크기의 Langerhans 도서(島嶼)에 비하여 더 활발하게 insulin을 분비(分泌)한다는 것을 시사(示唆)하는 것이다.

• The Korean Journal of Pharmacology
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• v.14 no.1_2
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• pp.13-23
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• 1978

1) It was attempted to clarify the sites of action of central (either intraventricular or intracisternal) norepinephrine(NE) and clonidine to cause cardiac slowing and hypotension in urethane-anesthetized rabbits. 2) NE produced cardiac slowing but indistinct effect on blood pressure. Clonidine produced cardiac slowing and hypotension. 3) Intraventricular and intracisternal administration of NE, clonidine, phenylephrine and isoproterenol did not make difference in their effects, except that the onset of cardiac slowing by intracisternal NE was more rapid than intraventricular NE. 4) Upon repeated administration of NE at the intervals of about two hours, blood pressure responses changed to the pressor ones, the cardiac slowing unchanged. By this procedure the cardiac slowing as well as the hypotension by clonidine were gradually diminished. 5) Clonidine, when given during the NE effects were persisting, did not produce the lowering of blood pressure and further decrease of heart rate. NE, when given during the clonidine effects were persisting, produced marked elevation of blood pressure but did not produce further decrease of heart rate. 6) After intraventricular administration of regitine or desmethylimipramine, the cardiac slowing effect of NE and the clonidine effects were not observed, whereas NE produced marked elevation of blood pressure. 7) Reserpinized rabbits showed pressor and cardiac accelerating responses to NE; slight pressor, and little cardiac responses to clonidine. 8) It seems that the cardiac slowing by both clonidine and NE as well as the hypotetsion by clonidine are mediated by the presynaptic ${\alpha}$-adrenoceptor in the brain but the pressor responses to NE and clonidine are mediated by other site(s) than the presynaptic ones.

• Journal of Chest Surgery
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• v.34 no.6
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• pp.485-489
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• 2001

Background: The most important factor in preventing sternal complications is stable sternal approximation. We have tried to find the most effective sternal closure method by examining the incidence of sternal dehiscence with or without infection in patients with cardiac surgery through median sternotomy. Material and Method: This study was performed in 489 patients over 45 years of age with median sternotomy for open cardiac surgery. Simple closure with interrupted 6 wires was performed in 159 patients, figure-of-8 closure technique in 119, overlapping interrupted closure using 10 wires in 150, and combined closure technique of interrupted simple closure and figure-of-8 suture closure in 61. Two hundred thirty-four patients underwent valve and aortic operations and 213 patients coronary artery bypass surgery. Result: Sternal dehiscence with or without infection occurred in 12 (2.5 %) patients. The complication developed in 5 of 159 patients (3.1%) with six interrupted simple closure, in 4 of 119 patients (3.4%) with figure-of-8 closure, and in 3 of 150 patients (2.0%) with overlapping interrupted closure using 10 wires, but there was no complication in 61 patients with combined closure technique (relative risk for other closure techniques, p<0.05). There was no significant difference in the incidence of the sternal complication between valve and aortic operation group and coronary artery bypass group (3.0% vs 2.3%, not significant), but diabetes mellitus was a significant independent risk factor (odds ratio and multivariate analysis, p<0.05). Conclusion: The sternal closure technique that combines simple interrupted suture closure and figure-of-8 suture closure may be a more useful technique to enhance sternal stabilization compared to other closure techniques, such as simple interrupted closure, 8-figure closure, and overlapping interrupted closure.