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Volume 36 (1986)
- Issue 6 Pages 1059-
- Issue 5 Pages 827-
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- Issue 3 Pages 423-
- Issue 2 Pages 237-
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Volume 36, Issue 3
Displaying 1-19 of 19 articles from this issue
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Toshio SAKAI1986 Volume 36 Issue 3 Pages 423-431
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSIn this minireview, the author summarized the works on rapid cooling contracture (RCC), including recent reports. RCC will be employed for studying the Ca2+ release mechanism from SR and mechanical properties during contraction.View full abstractDownload PDF (739K) -
Hikaru SUZUKI1986 Volume 36 Issue 3 Pages 433-440
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe effects of noradrenaline on membrane resistance of smooth muscle cells of the guinea-pig main pulmonary artery were assessed from the change in amplitude of electrotonic potentials produced by extracellulary applied current pulses. Noradrenaline was applied exogenously by bath application or endogenously by stimulating perivascular nerves. Exogenous noradrenaline depolarized the smooth muscle membrane with an associated increase in amplitude of electrotonic potentials and produced spike responses. Perivascular nerve stimulation evoked an excitatory junction potential with slow time course. The amplitude of electrotonic potential was slightly decreased during generation of the excitatory junction potential, but the reduction was less than that observed during current-induced depolarization. These observations suggest that the depolarizations produced by either endogenous or exogenous noradrenaline are accompanied by an increase in membrane resistance of arterial smooth muscle.View full abstractDownload PDF (620K) -
Shozo KOYAMA, Koichiro NISHIDA, Nobuyuki TERADA, Yumiko SHIOJIMA, Toru ...1986 Volume 36 Issue 3 Pages 441-450
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe present experiments were designed to study effects of neural control mechanisms on renal sympathetic nerve activity during acute portal vein distension in anesthetized dogs. Following the inflation of a balloon placed into the main portal vein of animals with the neuraxis intact (intact group), portal vein pressure at a site of the splanchnic regions increased significantly. Mean blood pressure (MBP) fell significantly and then renal vascular resistance (RVR) increased significantly in parallel with changes in portal venous pressure. In animals with sinoaortic denervation (SAD group), changes in portal venous pressure during the inflation of a balloon did not differ from the intact group. However, decreases in MBP in the SAD group were greater than that in the intact group, and sinoaortic denervation did not alter increases in RVR. In animals with both sinoaortic denervation and cervical vagotomy (vagotomy group), portal vein distension produced more profound hypotension, and significant increases in RVR occurred. This increase in RVR, however, was abolished by renal nerve denervation. The results of the present study indicate that increases in RVR during the portal vein distension, which is associated with systemic hypotension, may be mediated by an activation of efferent sympathetic renal nerves and modified by at least two neural reflex mechanisms such as carotid sinus baroreceptors and cardiopulmonary baroreceptors. In addition, local reflex systems such as stretch receptors in the venous wall of the portal vein may be involved in excitatory response to renal sympathetic nerve, leading to renal vasoconstriction, during the portal vein distension.View full abstractDownload PDF (660K) -
Tadahito SHIMADA, Takeshi HOSHI1986 Volume 36 Issue 3 Pages 451-465
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe effects of Na+ and pH in the medium on dipeptide transport across Triturus small intestinal brush border membrane were studied electrophysiologically. Although glycylglycine exists mainly in the zwitterionic form at pH 7.30, it induced marked depolarization in the membrane potential and reduction in the input resistance both in the presence and absence of Na+ in the medium. Similar Na+-independent depolarization and resistance change were also observed with L-carnosine. On the contrary, glycine induced membrane depolarization and reduction in the input resistance only in the presence of Na+ in the medium. When pH of the medium was lowered to 6.00, the magnitude of the depolarization induced by glycylglycine increased by 33%, while at pH 8.30, it decreased by 39%. These data indicate that dipeptide transport across the intestinal brush border membrane is coupled with H+ and has no direct interaction with Na+.View full abstractDownload PDF (963K) -
Hideyuki GONDO, Katsuko IKEDA, Masayosi GOTO1986 Volume 36 Issue 3 Pages 467-484
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSIonic mechanisms underlying Ba2+-induced automaticity in the bullfrog atrial muscle were studied by performing current and voltage clamp experiments using the double sucrose-gap technique. The application of Ba2+ of more than 0.01mM induced membrane depolarization, and its amplitude became larger with increasing [Ba2+]o. Pacemaker activity was initiated above 0.3mM Ba2+. Voltage clamp experiments revealed a marked decrease in the membrane conductance during hyperpolarizing steps, suggesting a depression of anomalous rectifier (Ikl). The time course of the outward current tail was fitted with a sum of fast (τ_??_0.8s) and slow (τ_??_4-5s) exponential components. The slow component (Ia) was markedly depressed by Ba2+, but the fast component (Ixs) remained. There was no significant change in the slow inward current (Isi). The hyperpolarization-activated current had an activation threshold of about -90mV and was depressed by Ba2+ at concentrations higher than 1mM. The pacemaker activity was suppressed by depleting either Na+ or Ca2+ in the bath solutions. The activation of the Isi might be responsible for both the later phase of the pacemaker depolarization and the rapid rising of the spontaneous action potential during low-voltage oscillation; the sodium current might take a similar role in the high-voltage oscillation. The Ixs may play the major role in generating the diastolic depolarization. The suppression of the Ikl and Ia by Ba2+ may provide a low background K conductance, which is essential for the initiation of the pacemaker activity.View full abstractDownload PDF (1303K) -
Zaiwen SHEN, Motoko YANASE, Kazuyuki KANOSUE, Teruo NAKAYAMA1986 Volume 36 Issue 3 Pages 485-496
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe effect of morphine injection into the midbrain periaqueductal gray (PAG) was examined on thermal response in rats. Rectal temperature (Tre) was recorded in unanesthetized and unrestrained animals before and after PAG morphine injection of 5 or 10μg in cold (10°C), neutral (22°C), and hot (34°C) environments. Both doses of morphine cuased hyperthermia. Sixty to 105min after the injection, Tre rose by 1.0-1.5°C regardless of ambient temperature. Naloxone (2mg/kg, i.p.) blocked the hyperthermic effects of morphine. Injection sites producing hyperthermia were distributed mostly in the ventral PAG and its ventral environs. The analgesic effect of morphine was examined by the tail-flick test. Locations of morphine injection effective for producing analgesia were restricted to the ventral area of the region responsible for hyperthermia. Magnitude of the hyperthermia did not significantly differ between animals with or without analgesia. The effect of PAG morphine (5μg) was tested on tail vasomotor response to hypothalamic and scrotal thermal stimulations in urethane anesthetized (1.0g/kg) animals. Threshold hypothalamic temperature for the vasodilation was lower at a scrotal temperature of 40°C than at 30°C. Following PAG morphine, threshold hypothalamic temperature rose and the difference in threshold hypothalamic temperature at the two scrotal temperatures disappeared.View full abstractDownload PDF (852K) -
Akira INOKUCHI, Yutaka OOMURA1986 Volume 36 Issue 3 Pages 497-509
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe effects of electrophoretically applied prostaglandin D2 (PGD2) on neuronal activity in the rat lateral preoptic area (LPOA) and posterior hypothalamic area (PHA) were examined. In the LPOA, 20% of the tested neurons were excited, 26% inhibited, and 6% showed bidirectional response. The direct effects often showed desensitization after repeated applications. Neurons excited by PGD2 were significantly sensitive (excitation) to acetylcholine (ACh). The ACh excitatory effect was sometimes (38%) attenuated, blocked, or reversed by concurrent PGD2 application. Excitatory or inhibitory effect of noradrenaline (NA) was not related to the effects of PGD2, however, modulation of the NA responses by PGD2 was common (58%). Inhibition, the predominant NA response, was changed to no effect or to excitation during simultaneous PGD2 application. Changes of the NA responses from inhibition to excitation, or from excitation to inhibition-excitation sequences were observed after PGD2 infusion into the third cerebral ventricle at low concentrations. In 43% of the cells, neurotransmission in the LPOA following ventral noradrenergic bundle stimulation was modified by PGD2 application. PGD2 application tended to reduce the duration of inhibition and to extend that of excitation. The direct effects of PGD2 in the PHA were similar to those in the LPOA. Desensitization was also observed in the PHA, but no interrelations were observed among the effects of PGD2, ACh, and NA. Modulation of ACh and NA responses by PGD2 was rarely seen in the PHA. Possible contributions of PGD2 to sleep and thermoregulation are discussed.View full abstractDownload PDF (994K) -
Hirokazu TOJIMA, Fumio KUNITOMO, Shinya OKITA, Yasutoshi YUGUCHI, Koic ...1986 Volume 36 Issue 3 Pages 511-521
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe effects of acetazolamide, a potent carbonic anhydrase inhibitor, and ammonium chloride (NH4Cl) on arterial blood gas tension, resting ventilation, and ventilatory responses to CO2 (HCVR) and hypoxia (HVR) were studied in healthy male subjects. Both drugs induced chronic metabolic acidosis with the reduction in plasma bicarbonate by a mean of 7.0±2.0 (S.D.) mM after acetazolamide and by 5.6±1.8mM after NH4Cl. The ratio in the decrement of PaCO2 to that of plasma bicarbonate (ΔPaCO2/Δ[HCO3-]) was 1.51 in the former and 0.98 in the latter. Both drugs increased inspiratory minute ventilation (VI) predominantly due to increased tidal volume (VT) with acetazolamide and to increased respiratory frequency (f) with NH4Cl. In HCVR, the increments in CO2-ventilation slope and in ventilation at PETCO2 60mmHg after drug administration were 0.77±0.51l•min-1•mmHg-1 and 20.0±11.2l/min with acetazolamide and 0.59±0.40l•min-1•mmHg-1 and 8.0±2.8l/min with NH4Cl, respectively. On the other hand, HVR both in terms of ΔVI/ΔSaO2 slope and of ventilation at SaO2 75% significantly increased after NH4Cl but not after acetazolamide administration. Thus, augmented VT and HCVR in the acetazolamide group and increased f and HVR in the NH4Cl group suggested that the central chemosensitive mechanism in the former and the peripheral chemosensitive mechanism in the latter may predominantly be responsible for the elevated ventilatory activities.View full abstractDownload PDF (741K) -
Kenji TAKI, Keishi MIZUNO, Nobuaki TAKAHASHI, Reiji WAKUSAWA1986 Volume 36 Issue 3 Pages 523-532
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSCarbonic anhydrase in the red blood cell and in the pulmonary endothelium facilitates the elimination of CO2 in the lungs. Although a carbonic anhydrase inhibitor, such as acetazolamide which is frequently used in patients with glaucoma or with metabolic alkalosis, is known to impair the CO2 elimination in the lungs, the dose-response curve of CO2 elimination with acetazolamide has not been well documented in CO2 homeostasis. In the present study, the effects of inhibited carbonic anhydrase were tested in 8 anesthetized dogs; various dosages of acetazolamide were used. When the administered clinical dosage of acetazolamide increased from 5 to 20mg/kg, PaCO2, PvCO2, arterial-alveolar PCO2 difference (a-ADCO2), and physiological VD/VT ratio increased progressively to 52.0±2.1Torr, 58.0±3.0Torr, 23.4±1.2Torr, and by 19.2±1.8% (S.E.) respectively, whereas inhibition rate of red blood cell carbonic anhydrase (RCA) activity increased progressively to 73.1±2.1% (S.E.). On the other hand, PACO2 decreased to 27.1±1.8Torr (S.E.) upon the first injection of 5mg/kg of acetazolamide, but PACO2 did not change further upon 3 additional 5mg/kg injections. Mixed venous-arterial PCO2 difference ((v-a)PCO2), VCO2, and anatomical VD/VT ratio were unchanged by the administration of any doses of acetazolamide.View full abstractDownload PDF (630K) -
Hisaharu KOHZUKI, Yasunori ENOKI, Yoshimi OHGA, Susumu SAKATA, Satoshi ...1986 Volume 36 Issue 3 Pages 533-541
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSBecause oxygen affinity of canine red cells had been hardly reduced by the conventional procedure of incubation with inosine-pyruvate-phosphate or dihydroxyacetone-pyruvate-phosphate, incubation with acidified phosphoenolpyruvate (PEP) medium was tested for its effect on oxygen affinity. As this procedure had been shown to induce a significant increase of 2, 3-diphosphoglycerate (DPG) in human red cells, it was also proved to be effective for lowering oxygen affinity of canine red cells. Incubation with 15mM PEP in ACD medium (pH 6.0) at 37°C for 30min was the standard procedure established after critical scrutiny. The incubated blood exhibited an average increase in half-saturation pressure (P50) amounting to 7Torr (pH 7.40, PCO2 40Torr, 37°C), with no appreciable hemolysis and little change in mean corpuscular hemoglobin concentration. Results with Dowex 1-X8 anion exchange chromatography of acid soluble phosphates from the incubated red cells suggested that PEP penetrated rapidly through, the canine red cell membrane and was metabolized to DPG via the retrograde process of the Embden-Meyerhof glycolytic pathway.View full abstractDownload PDF (604K) -
Osamu SHIDO, Tetsuo NAGASAKA1986 Volume 36 Issue 3 Pages 543-554
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSChanges in blood pressure, heart rate, and heat balance during febrile response to E. coli endotoxin were studied in unanesthetized guinea pigs at an ambient temperature of 24°C. The heat balance was measured with direct and indirect calorimetry. An intravenous injection of endotoxin (5μg•kg-1) produced characteristic biphasic changes in the intra-aortic temperature (Tar), heat production (M), and heat loss (H). The response of arterial blood pressure (BP) to the endotoxin was monophasic and that of heart rate appeared tiphasic. Phenylephrine (PHE: 20μg•kg-1•min-1) infused intravenously in the two rising phases of fever increased BP to the same extent, but the amount of the reflexive bradycardia seemed to be less during the first rise of Tar. The increased metabolism (shivering and nonshivering thermogenesis) during fever development was suppressed by PHE infusion at the two rising phases. The results conclude that, in guinea pigs, the baroreflexive suppression of metabolism is persistent during fever development, but the reflex sensitivity may be different at different phases of fever.View full abstractDownload PDF (837K) -
Osamu SHIDO, Tetsuo NAGASAKA, Yuko NODA1986 Volume 36 Issue 3 Pages 555-564
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe effects of chronic administration of naloxone (120-150μg•kg-1•h-1) on the wheel running activity (WR) and on food and water intakes were studied in male Wistar rats subjected to a 2-h restricted feeding (1200-1400h) schedule at 24±1°C and LD 12:12 (L: 0600-1800h) cycle. The restricted feeding significantly increased WR before and after the feeding time. Food and water intakes per day were reduced and body weight gradually decreased for the 2-week food restriction period. Food and water intakes appeared to be suppressed by naloxone, particularly shortly after the administration. The chronically administered naloxone slightly increased the 24-h WR. In the naloxone-treated rats, the fraction of WR before the feeding time (anticipatory activity) was significantly increased compared with saline-treated rats. The fraction of WR after the feeding time (succeeding activity) did not change. These results suggest that the endogenous opioid system may play a role in suppressing the excess increase in the anticipatory locomotor activity in the food restricted rats.View full abstractDownload PDF (768K) -
Takashi NAKAHARI, Hideyo YOSHIDA, Manabu MIYAMOTO, Yusuke IMAI1986 Volume 36 Issue 3 Pages 565-583
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe method of electrical impedance measurement was tested for its usefulness in monitoring of extra-cellular fluid (ECF) in the dog submandibular gland during salivary secretion. Measurements were performed during rest and stimulated state with or without blood supply. During stimulation with blood supply, the conductivities of the gland decreased to some extent. During stimulation without blood supply, the decrease in conductivities was markedly enhanced. The decrease of ECF compartment during stimulation without blood supply was ascertained by the stereological measurement. Coincidence of conductivity decrease and histologically observed decrease of ECF compartment supports the usefulness of impedance measurement for monitoring of ECF during secretory activity of gland tissue. The present study also shows that the interlobular space decreased mainly during stimulation when blood supply is absent. This indicates that, among ECF space, the interlobular space plays an important role as a fluid reservoir in the salivary gland.View full abstractDownload PDF (1617K) -
Dissociation between Changes in Renal Nerve Activity and Renal Vascular Resistance in Conscious DogsHironobu MORITA1986 Volume 36 Issue 3 Pages 585-593
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe effects of acute volume expansion and hemorrhage on renal nerve activity and renal vascular resistance were examined in chronically instrumented conscious dogs. In six conscious dogs, when the blood volume was expanded by 18ml/kg, the mean arterial pressure increased by 14±3mmHg, mean left atrial pressure increased by 5.3±0.7mmHg, and renal nerve activity decreased by 87±3%, while the renal blood flow was not altered significantly and renal vasoconstriction occurred, i.e., the calculated renal vascular resistance increased by 12±4% from 0.49±0.05mmHg/ml/min. Volume depletion, induced by 20ml/kg hemorrhage, did not alter the mean arterial pressure (-4±6mmHg), while it decreased the mean left atrial pressure by 4.0±0.7mmHg and increased the renal nerve activity by 200±67%. However, the renal blood flow was well maintained at the pre-hemorrhagic control level and renal vasoconstriction did not occur. Thus, in conscious dogs, acute volume changes altered the renal nerve activity dramatically, but these changes in renal nerve activity did not exert any significant effects on renal vascular resistance.View full abstractDownload PDF (626K) -
Hideki GOTOH, Toshifumi TAKENAKA, Eisuke NISHIDA, Hikoichi SAKAI, Akir ...1986 Volume 36 Issue 3 Pages 595-600
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe particle transport in axons permeabilized with saponin was blocked by three actin-related proteins, 88K protein/actin complex, actinogelin, and cofilin. The particle movement was reactivated by ATP, but neither by GTP nor by ITP. We conclude that an actin and a dynein-like protein are involved in retrograde phase of axoplasmic transport mechanism.View full abstractDownload PDF (391K) -
Yu-Liang SHIH1986 Volume 36 Issue 3 Pages 601-605
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe hyperpolarizing effect (H-effect) of d-tubocurarine on the end-plate of the isolated diaphragm pretreated with an anticholinesterase was irreversibly abolished by toosendanin (1×10-5g/ml), indicating the blockade of spontaneous non-quantal release of acetylcholine (ACh). The H-effect was also inhibited, but temporarily, when toosendanin (a dose of 0.6LD50) was subcutaneously injected into the mouse and the diaphragm was isolated 40-120min after injection. During such an inhibitory period, however, spontaneous release of ACh remained facilitated. It is concluded that the effect of toosendanin on non-quantal release of ACh was different from its effect on quantal release not only at the direction but also at the time course.View full abstractDownload PDF (324K) -
Hiroshi NOSE, Eizo SUGIMOTO, Taketoshi MORIMOTO, Seiji USUI, Takashi A ...1986 Volume 36 Issue 3 Pages 607-611
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSA new continuous measuring system for blood sodium concentration and blood volume in conscious rats is described. A small extracorporeal circulation was made and the blood was passed through a sodium sensitive glass electrode and a γ-counter. Applying the system to conscious rats, the effect of various salinities of drinking water was detected from the change in blood sodium concentration.View full abstractDownload PDF (297K) -
Masatsugu NAKAI, Yoko YAMANE, Yukihisa UMEDA, Jin YAMAMOTO, Yukio MATS ...1986 Volume 36 Issue 3 Pages 613-618
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSMonopolar electrical stimulation of the intermediate portion of the solitary nucleus in spontaneously hypertensive rats (SHRs) with cervical cordotomy and vagotomy resulted in a 1.68 times greater increase in plasma vasopressin concentration than in Wistar rats. The result implies that such an enhanced function of the central neural mechanism to release vasopressin in SHR backs up the functionally aberrant cardiovascular receptors.View full abstractDownload PDF (470K) -
Seiji YAMADA1986 Volume 36 Issue 3 Pages 619-623
Published: 1986
Released on J-STAGE: July 28, 2006
JOURNAL FREE ACCESSThe protein concentration of the thoracic duct lymph and the amount of protein transported by the thoracic duct decreased during an acute heat stress in rats. The changes in regional lymph flow into the thoracic duct were calculated and the ratio of the lymph from the skin increased 13% and that from the visceral organs decreased 6% during heat stress.View full abstractDownload PDF (369K)
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