巻号一覧
39 巻, 6 号
選択された号の論文の17件中1～17を表示しています
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Shigemi MOR1989 年 39 巻 6 号 p. 785-809
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーPDF形式でダウンロード (2267K) -
Noriko IIDA, Yoshinori MITAMURA1989 年 39 巻 6 号 p. 811-823
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーIn order to establish the nature of the stretch-evoked dynamic properties of vascular smooth muscle in arterioles, we have examined the static and dynamic effects of both arterial pulse pressure and elevated venous pressure on the resistance vessels (arteries and arterioles) in an intestinal mesenteric preparation derived from dogs. The dynamic myogenic response to stretch stimuli was directly related to both the frequency of arterial pulse pressure (1-20c/min) and the level of venous pressure (0-45mmHg). Under elevated venous pressure (20mmHg), the mean arterial flow decreased with an increase in the frequency of arterial pulse pressure. The arteriolar vascular tone (namely, vascular resistance) was seen to be enhanced. We found that elevated venous pressure promotes active constriction (9-53%) of arteriolar smooth muscle (myogenic mechanism). The elevation of venous pressure also caused a rhythmic constriction (vasomotion) in the site of both vein and artery, which was completely abolished by an α-blocker (phentolamine). The results suggest that during venous pressure elevation a very pronounced myogenic constriction in terminal arterioles is caused by either a local neural reflex or a propagated myogenic response in the arteriolar network.抄録全体を表示PDF形式でダウンロード (939K) -
Kosuke MINAMISAWA, Ryuhei HASHIMOTO, Masao ISHII, Fukuko KIMURA1989 年 39 巻 6 号 p. 825-832
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーThe role of endothelin (ENT) in the control of systemic blood pressure (BP) was examined in conscious rats. Intracerebroventricular (i.c.v.) administration of ENT (0.002 or 0.2μg, i.e., 0.78 or 78pmol/2μl 0.9% saline) to conscious rats had complicated effects on BP. A significant fall in BP occurred in the initial 2-4min after administration; and then after recovery toward the control level, BP decreased again within 17min, following which a constant rise in BP occurred. In addition to the changes in BP, 3 of 9 rats which received 0.2μg lapsed into severe barrel rotation-like behavior only to die 6-8min after i.c.v. injection. It was therefore assumed that ENT had central effects on BP regulation and motor activity.抄録全体を表示PDF形式でダウンロード (575K) -
Satoshi SHIMIZU, Susumu SAKATA, Yasunori ENOKI, Yoshimi OHGA, Izumi OK ...1989 年 39 巻 6 号 p. 833-846
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーTemporal changes of plasma erythropoietin (Epo) in mice exposed to hypobaric hypoxia were studied by a fetal mouse liver cell culture method. Since a colony formation inhibitory activity was found in the mouse plasma, thirteen pretreatment procedures for bioassay were compared and the procedure of shaking with chloroform followed by dialysis was concluded to be the best. When normal mice (P50=40.4±2.2 Torr) were exposed to hypoxia of 350Torr, the plasma Epo level was elevated, with peak at the 2nd to 3rd day, and afterwards declined gradually. On the contrary, cyanated mice (P50=30.1±1.5Torr) showed much less of the Epo response when exposed to 350Torr. Under 200Torr hypoxia, both mice exhibited a similar and remarkable extent of the response. These results suggest that the renal Epo-producing tissue or its oxygen-sensing system is less hypoxic in cyanated mice than in normal mice under 350Torr, and that the physiologically optimal oxygen affinity of blood is variable depending on hypoxic degrees. The fact that the inhibitory activity showed an inverse temporal change to that of Epo, suggested a possible important role of this activity in the regulation of erythropoiesis under hypoxia.抄録全体を表示PDF形式でダウンロード (940K) -
Yumi TAKEMOTO, Juro IRIUCHIJIMA1989 年 39 巻 6 号 p. 847-855
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーChanges in regional blood flow and arterial pressure in the rat during spontaneous walk in a wheel were observed. An electromagnetic flow probe was implanted around the carotid, superior mesenteric, or renal artery, or the terminal aorta and a catheter for pressure measurement was inserted into the terminal aorta or the common carotid artery. The wheel had a diameter of 35cm and rotated passively as the rat walked. When hindquarter (terminal aortic) flow increased markedly during wheel walk, carotid flow decreased, superior mesenteric flow decreased or remained unchanged, and renal flow did not change. Arterial pressure remained almost unchanged and heart rate increased an average of about 10%. Semiquantitative considerations indicated that arterial pressure was maintained in the face of the profuse increase in hindquarter flow during wheel walk by an increase in cardiac output rather than shifts of blood flow from other regions.抄録全体を表示PDF形式でダウンロード (633K) -
Ryoko MARUYAMA, Akio YOSHIDA, Yasuichiro FUKUDA1989 年 39 巻 6 号 p. 857-871
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーTo estimate the sensitivity to hypoxic inhibition of various regulatory processes for respiration, changes in breathing pattern during hypoxic ventilatory depression (HVD) were analyzed in the halothane-anesthetized spontaneously breathing rat using a "progressive isocapnic hypoxia test." In the carotid sinus nerve (CSN) intact rats, ventilatory augmentation was followed by depression due to reduction in respiratory frequency (f) at end-tidal PO2(PETO2) levels below 50-60mmHg despite increased afferent activities from the carotid chemoreceptors. After CSN section, ventilation was progressively depressed at PETO2 lower than normoxic level with simultaneous decreases of f and tidal volume. An increase in CO2 stimulus or the prevention of arterial hypotension during hypoxia by infusing a vasoconstrictor agent (phenylephrine) inhibited the occurrence of ventilatory depression in both the CSN intact and denervated animals. In all cases studied, the reduction in f resulted mainly from the prolongation of expiratory time (TE). The results suggest that in the anesthetized rat the effect of respiratory stimulation from carotid chemoreceptor afferents becomes inadequate to offset the prolongation of TE due to the central hypoxia at lower PETO2, and that the neural process for regulating TE is the major site of deterioration during central hypoxic inhibition. Roles of CO2 stimulus and systemic circulatory conditions in the generation of HVD were also discussed.抄録全体を表示PDF形式でダウンロード (1170K) -
Hidenori SAKO, Sunao IMANISHI, Makoto ARITA, Tatsuo SHIMADA, Tetsuo HA ...1989 年 39 巻 6 号 p. 873-890
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーTo investigate the role of the electrogenic Na-K+ pump in the resting membrane of "diseased" or "depolarized" human atrial muscles, intracellular K++ activity (aiK+) and resting membrane potential (Vm) were simultaneously measured using double-barreled K++-selective microelectrodes. Under perfusion with normal Tyrode's solution (37°C) containing 5.4mM [K+]0, Vmaveraged -43.9±1.4mV, and aiK+ was 99.7±1.3mM (mean±S.E., n=33). The aiK+ was comparable to that of atrial muscles obtained from other intact mammalian species. In 5.4mM [K+]o, dihydro-ouabain (DHO) at concentrations of 10-6 and 10-5M significantly decreased aiK+ and depolarized Vm. Similar decreases in aiK+ were observed when [K+]o was decreased from 5.4 to 0.5mM or when the temperature of the perfusing solution was decreased from 37 to 22°C. Upon returning [K+]o from 0.5 to 5.4mM at 37°C, aiK+ increased, Vmhyperpolarized markedly for about 3min, and this was followed by less marked levels of hyperpolarization in the steady state. The high [K+]o-induced increases in aiK+ were inhibited in the presence of DHO, and at low temperature (22°C). Isoproterenol (10-7M) increased aiK+ and hyperpolarized Vm. Acetylcholine (10-5M) hyperpolarized Vmwith no change in aiK+. The rate of reduction of Na+-efflux during application of DHO (10-5M) was calculated based on the change in aiK+ and surface-to-volume ratio of the cell measured electronmicroscopically in the same tissue, and estimated to be 2.6 to 3.8pmol/(cm2•s), close to the value reported for Purkinje fibers excised from intact animals. We conclude that the Na-K+ pump functions normally even in "diseased" human atrial muscles, thereby keeping aiK+ within a physiological range.抄録全体を表示PDF形式でダウンロード (1203K) -
Kyoko MIYASAKA, Akihiro FUNAKOSHI, Rieko NAKAMURA, Kenichi KITANI, Ken ...1989 年 39 巻 6 号 p. 891-899
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーTwo types of pancreatic secretory trypsin inhibitors (PSTIs) were recently purified from rat pancreatic juice. One consisted of 61 (PSTI-61) and the other of 56 (PSTI-56) amino acid residues. PSTI-61 has been reported to elicit cholecystokinin (CCK) release when injected into the duodenum. Since no information has been available about the action of PSTI-56 on CCK release, the two PSTIs were compared for their stimulatory effect on CCK release and pancreatic exocrine secretions in conscious rats after intraduodenal administration. Rats were prepared with bile and pancreatic fistulae and with two duodenal cannulae. Pancreatic juice was excluded from the duodenum for 48h prior to the experiment because rat PSTIs were trypsin sensitive. PSTI-61 significantly stimulated pancreatic secretions and increased plasma CCK concentrations from 3.6 to 6.5pM, whereas PSTI-56 had no effect on either CCK release or pancreatic secretions. It is suggested that the action as a regulator for CCK release and pancreatic secretions is possessed only by PSTI-61, but not by PSTI-56.抄録全体を表示PDF形式でダウンロード (638K) -
Akihiro FUNAKOSHI, Kyoko MIYASAKA, Kenichi KITANI, Susumu FUNAKOSHI, H ...1989 年 39 巻 6 号 p. 901-905
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーWe have reported that porcine pancreastatin inhibits cholecystokinin (CCK)-stimulated pancreatic exocrine secretion in conscious rats. In the present study, the effects of mammalian pancreastatins on exocrine pancreatic functions in rats were compared using synthetic pancreastatins (porcine, bovine, human, and rat). Rats were prepared with cannulae draining pure pancreatic juice and bile separately and a duodenal cannula to return bile-pancreatic juice to the intestine and with a jugular vein cannula. After 90-min basal collection of pancreatic juice, CCK-8 (100pmol/(kg•h)) was infused for 3h with or without pancreastatins (100pmol/(kg•h)). All pancreastatins significantly inhibited protein output at an equivalent molar potency. These results suggest that mammalian pancreastatins have the same biological activity of a comparable magnitude and exert a similar biological action on the exocrine pancreas.抄録全体を表示PDF形式でダウンロード (378K) -
Setsuko KANAI, Kenichi KITANI, Yuko SATO1989 年 39 巻 6 号 p. 907-918
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーA hypothesis for the mechanism of bile salt-induced choleresis with increased bile bicarbonate concentration (cholehepatic recycling; CHR), requires a relatively high pK′a value of a bile salt to be easily protonated in bile canaliculi. If the choleresis induced by taurodeoxy-cholate and glycodeoxycholate (which increase bile bicarbonate concentration in rabbits) is to be explained by this thesis, these bile salts must be extensively deconjugated in the liver, enabling a bile salt having a higher pK′a value, free deoxycholate, to undergo CHR. With a stepwise increase in the infusion rate, the increments of bicarbonate concentration, as well as the bile flow rate induced by taurodeoxycholate and glycodeoxycholate, were as efficient as those caused by an equimolar infusion of deoxycholate. With infusion of conjugated deoxycholates, the major bile salts excreted in the bile were those which had been infused. In studies with conjugated deoxycholates, unconjugated deoxycholate was not detectable in the bile. Furthermore, deoxycholate concentration in the liver significantly increased after a 2-h infusion of deoxycholate but did not increase after infusion of either glycodeoxycholate or taurodeoxycholate. The present results suggest that the choleresis induced by conjugated deoxycholates in rabbits requires an explanation other than CHR of deoxycholate.抄録全体を表示PDF形式でダウンロード (864K) -
Byungchul AHN, Yoshikazu SAKAKIBARA, Poul-Erik PAULEV, Atsuko MASUDA, ...1989 年 39 巻 6 号 p. 919-929
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーCirculatory and ventilatory responses to lower body negative pressure (LBNP) were simultaneously investigated in 8 healthy men before, during, and after the application of -20, -40, and -60mmHg pressure. Minute ventilation (VE) decreased during LBNP due to a fall in respiratory frequency with sustained tidal volume. The cardiac output (Q) was reduced in proportion to the applied LBNP exposure, while VE decreased to almost the same level at all LBNP applications. In spite of decreased VE, end-tidal PO2 and PCO2 were increased and decreased, respectively, indicating a relative alveolar hyperventilation. The ventilation equivalent for O2 (VE/VO2) increased, while the cardiac output equivalent for O2 (Q/VO2) decreased. The relation between VE/VO2 and Q/VO2 showed a significant negative correlation (r=-0.93, p<0.01). The veno-arterial CO2 concentration difference (CvCO2-CaCO2) increased with LBNP, due to a fall in CaCO2 with constant CvCO2. The constant CvCO2 indicated a constant tissue acid-base balance. These observations suggest the existence of a ventilatory mechanism improving the efficiency of respiration in order to compensate for the sustained LBNP depression of Q at a given gas exchange.抄録全体を表示PDF形式でダウンロード (764K) -
Hironobu MORITA, Yasuhiro NISHIDA, Kenji KANGAWA, Naoto MINAMINO, Hisa ...1989 年 39 巻 6 号 p. 931-941
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーThe contribution of the renal nerve to the natriuretic and diuretic responses to rat atrial natriuretic peptide (rAMP) was investigated in conscious rabbits with unilateral renal denervation. Renal nerve activity (RNA) was measured at the contralateral innervated kidney. Catheters were bilaterally implanted into the ureters. Urine samples were collected from each kidney by gravity drainage at 10-min clearance intervals. In rabbits with all baroreflexes intact, infusion of rANP at 0.3μg/(kg•min) for 30min decreased mean arterial pressure by 8±4mmHg and increased RNA by 53±13%. After sinoaortic baroreceptor denervation (SAD), hypotensive response to infusion of rANP was greater than that in intact rabbits, while RNA did not change. After SAD plus vagotomy, infusion of rANP lowered mean arterial pressure by 21±4mmHg and RNA by 19±6%. In the denervated kidney, infusion of rANP increased Na+ excretion by 16.1±4.5 from 3.5±1.0μEq/min and water excretion by 0.17±0.05 from 0.08±0.02ml/min. In the contralateral innervated kidney, infusion of rANP increased the amount of Na+ and water excretion by 4.5±3.2μq/min and 0.07±0.04ml/min, which were significantly less than those in the denervated kidney. These results indicate that infusion of rANP increases RNA, due to baroreceptor reflexes, and that this increase in RNA blunts natriuretic and diuretic action of rANP.抄録全体を表示PDF形式でダウンロード (841K) -
Takao OKADA1989 年 39 巻 6 号 p. 943-948
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーStability of cardiac function and myocardial intracelluar ionic composition was examined in the Krebs-perfused isolated rat working heart. Hearts perfused by a conventional Krebs solution showed stable contraction for 2h, but during this period, intracellular ionic environment (Na, K, Ca) substantially changed. Addition of dextran to the perfusate inhibited, though not completely, this time-dependent deterioration and made the heart less vulnerable to the hypoxia-reoxygenation.抄録全体を表示PDF形式でダウンロード (377K) -
Hideki OHNO, SHINSEI GASA, Minoru ONO, Chihiro SEKIYA, Akihiro KUROSHI ...1989 年 39 巻 6 号 p. 949-955
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーEffects of acute and chronic stresses (exercise, cold, and immobilization) on γ-glutamyltransferase (γGT) activity in the rat kidney were investigated. In the extramicrosomal fraction there were significant decreases in acute-exercised rats but significant increases in cold-adapted and immobilized rats. In the microsomal fraction, on the other hand, the γGT activity of acute-exercised rats increased definitely. The results suggest that different types of stresses have different effects on γGT activity in the rat kidney.抄録全体を表示PDF形式でダウンロード (454K) -
Keiji YOSHIOKA, Toshihide YOSHIDA, Motoharu KONDO1989 年 39 巻 6 号 p. 957-962
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーMice treated neonatally with monosodium-L-glutamate (MSG) are known to develop into obese adults without hyperphagia, which are characterized by the reduced levels in the resting metabolic rate (RMR) and the thermogenesis of brown adipose tissue (BAT) in the thermoneutral environment. The present study revealed that an acute cold-exposure (5°C, 1h) of these animals resulted in the increase in norepinephrine turnover and mitochondrial-5′-diphosphate (GDP) binding in the interscapular BAT as well as the guanosine RMR, suggesting a normal thermogenic responsiveness of BAT to cold.抄録全体を表示PDF形式でダウンロード (446K) -
Zdravko VELKOV, Radoslav LOLOV, Toshikazu YOSHIKAWA, Nicola NICOLOV1989 年 39 巻 6 号 p. 963-967
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーThe participation of the heart in shock syndrome formation during endotoxin shock is a problem still awaiting solution. The task undertaken is to assess the work of the left ventricle and arterial pressure in rabbits before and after endotoxin injection at a dose of 2mg•kg-1. Heart rate is the first to reach significantly lower values-at 30min (p<0.05). At 45min, there are significant reductions in dP/dtmax (p<0.01), (dp/dt)/P40 (p<0.001), LVP (p<0, 05), and increase in dP/dtneg (p<0.02). Both the systolic and diastolic blood pressures were significantly decreased at 60min. The data obtained warrant the assumption that impaired myocardial contractility plays a part in the formation of shock syndrome in rabbits exposed to endotoxin.抄録全体を表示PDF形式でダウンロード (333K) -
R. P. SINGH, R. C. SINHA1989 年 39 巻 6 号 p. 969-973
発行日: 1989年
公開日: 2006/07/28
ジャーナル フリーLiver glycogen and lipid, ovarian glycogen, and lipid index were used as criteria to elucidate energy changes associated with reproduction and biphasic pattern of dormancy (summer and winter) in the female forg, Rana tigrina. Liver glycogen showed 2 peaks; the ovarian glycogen showed reciprocal relationship with that of liver. The liver lipid and glycogen showed parallel trend.抄録全体を表示PDF形式でダウンロード (335K)
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