All issues
Successor
Volume 31 (1981)
- Issue 6 Pages 809-
- Issue 5 Pages 613-
- Issue 4 Pages 445-
- Issue 3 Pages 285-
- Issue 2 Pages 131-
- Issue 1 Pages 1-
Volume 31, Issue 3
Displaying 1-15 of 15 articles from this issue
- |<
- <
- 1
- >
- >|
-
Makoto TAKADA, Hideo HAYASHI1981 Volume 31 Issue 3 Pages 285-303
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe epidermal effects of activator (cadmium) or inhibitors (calcium and amiloride) as well as their interactions in active Na trans-port through bullfrog abdorminal skin were analyzed kinetically.Cad-mium at 1 mM increased the short circuit current (SCC) to 126%.The Hill coefficient (n) for the relation between [Cd2+] and SCC was O. 737, which indicated negative cooperation.Calcium at over 8 mM decreased the SCC to 80% at its maximum effect.Calcium inhibited the Cd2+-induced SCC at lower [Cd2+], and facilitated it at higher [Cd2+].Calcium acted uncompetitively on the binding reaction of Na+with a Na entry channel. Cd2+alone or Cd2+ under the influence of calcium also acted uncom-petitively on the reaction. Amiloride at 5×10-5M inhibited the SCC almost completely.The Hill coefficient in the relation between amilo-ride and SCC was 0.757, indicating the presence of negative cooperation. In contrast to the effect of calcium, the Cd2+-induced SCC was much reduced at higher [amiloride].Amiloride inhibited the channel-Na binding reaction in a mixed manner (competitive+noncompetitive), while Cd2+ activated the reaction under the influence of amiloride noncomoeti-tively. From the SCC model based on the hypothesis that the kinetic constants are invariable even under interaction of the activator and inhibitors, the percentage of the various forms of channel ion complex were calculated. The SCC was then calculated, assuming that it was directly proportional to the sum of the rate of decomposition of chan-nel·Na complex and the higher rate of decomposition of chan-nel·Na·Cdn complex.The above assumption is supported by the fact that there is good agreement between the calculated SCC and experimentally ob-tained SCC in the mixture of the activator and the inhibitor.View full abstractDownload PDF (1874K) -
Kozo HIRATA, Tetsuo NAGASAKA1981 Volume 31 Issue 3 Pages 305-316
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSCardiac output (Q) and regional blood flow to various tissues were measured by γ-labeled plastic microspheres (15± 3μm) injected into the left ventricle at rest and during 30-min infusion of norepinephrine (NE infusion, 2μg/kg · min) in either anesthetized or unanesthetized con-trol (CT) and cold-acclimated (CA) rats.Besides cardiovascular func-tions, oxygen consumption (VO22) and colonic temperature (Tco1) were measured.Under anesthesia (the rat was immersed into warm and initial Tco1 was kept at around 37.6°C), NE infusion produced significant increases in VO22, Q and blood flow to most of the tissues measured both in CT and CA rats.The increases in VO22 and blood flow to the brown adipose tissues (BAT) were significantly higher in CA rats.Both in CT and CA rats, heart rate (HR), blood pressure (BP), Q, tissue blood flow, and VO22 at rest were significantly higher in unanesthetized conditions (Ta 17°C) than in anesthetized condition.In unanesthetized rats, these resting values were significantly higher in CT than in CA.In CT rats, NE infusion pro-duced decreases in HR, Q and blood flow to most of the tissues measured.The reductions in blood flow to BAT and skeletal muscles were particularly consistent.In CA rats, NE infusion produced significant increases in Q and blood flow to most of the tissues measured particularly in BAT.Blood flow to the ear was decreased. VO22 and TCO1 increased.The mass of BAT in CA rats was twice as much as that in CT animals.The result indicates that, in contrast to CT rats, CA rats can increase cardiac output and blood flow to BAT with NE in either anesthetized or unanesthetized conditions, which might be responsible for the significant calorigenic response to NE in these rats.View full abstractDownload PDF (1423K) -
Takuro OSA, Toshiyasu OGASAWARA, Seishi KATO1981 Volume 31 Issue 3 Pages 317-329
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSOvariectomized rats were given one-shot injections of 10μg estradiol-17β benzoate, and the longitudinal muscle of the uterus was used for experiment 4 days later. The membrane potential was 58.8± 2.4mV, and the membrane activity consisted of repetitive spike potentials carried on a plateau potential. Oxytocin (1mU/ml) caused a depolarization of 7.6±3.7mV in a Mg-free Locke solution, a prolongation of burst discharge and increase in the frequency of spontaneous activity. The effects were potentiated by 1-3mM Mg. Burst discharge was abol-ished by the application of 0.5mM Mn, and resumed when 0.1mU/ml oxytocin was applied. Depolarization up to about -30mV and a con-tracture were caused by 1mU oxytocin when applied with 1-2mM Mn. The excitatory effect of oxytocin was depressed by 5mM Mn. Marked depolarization and contracture were produced by 1 mU oxytocin when the application of Mn was discontinued (rebound phenomenon). The above observations indicate the superficial site of Mg and Mn at low concentration in cooperative action with oxytocin, and an additional site of Mn for the rebound potentiation of contraction and depolariza-tion. It is proposed that oxytocin accelerated Mn influx, and that intra-cellular Mn participates in electrical and contractile responses due to the application of oxytocin. In this respect, acetylcholine caused a similar effect.View full abstractDownload PDF (3207K) -
Masaji MOCHIZUKI, Kyuichi NIIZEKI, Masakazu TAMURA1981 Volume 31 Issue 3 Pages 331-344
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSWhen blood in the pulmonary capillary is oxygenated in hypercapnic air, PCO2 in the red cell has been thought to exceed alveolar PCO2 due to the Haldane effect, inducing outward CO2 diffusion.As long as the inward CO2 diffusion and, consequently, HCO3-formation are prevented in the red cell, the CO2 gain in plasma is reduced down to the level predicted from a CO2 dissociation curve of separated plasma. Therefore, if the direction of the CO2 diffusion is not reversed during the contact time, the virtual venous PCO2 (PEq), where the CO2 loss due to the Haldane effect is balanced with the gain due to the venoalveolar PCO2 gradient, becomes higher than the oxygenated venous PCO2 in proportion to the CO2 difference between the true and separated plasma. In order to verify the validity of the above assumption, the PEq value was measured in normo- and hypercapnia by using the Defares'extrapolation method in six normal subjects.The results obtained revealed that the PEq estimated in hypercapnia was obviously higher than that in normo-capnia. The above difference was significantly greater in normoxia than in hypoxia.Furthermore, it agreed fairly well with the theoretical difference presumed by taking the difference in CO2 content between separated and true plasma and the R.Q.effect on the alveolar gas volume into account, suggesting that the inward CO2 diffusion following the oxygenation reaction could be disregarded in normoxic hypercapnia.View full abstractDownload PDF (1489K) -
Masaji MOCHIZUKI, Hiroshi TAZAWA, Kyuichi NIIZEKI, Masakazu TAMURA1981 Volume 31 Issue 3 Pages 345-355
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSWhen mixed venous blood is oxygenated in alveolar air with higher PCO2, the PCO2 within the red cell is thought to exceed the alveolar PCO2 due to the Haldane effect and to block the inward CO2 diffusion. If the direction of the CO2 diffusion is not reversed during the contact time, the HCO3-gain in the plasma will not exceed the amount estimated from venoalveolar PCO2 difference by using a CO2 dissociation curve of separated plasma.In order to clarify the validity of the above thought, the venoarterial CO2 content difference was measured by using a van Slyke apparatus and a PCO2 electrode at various alveolar PCO2 levels in rebreathing dogs.The HCO3-rise in the whole blood was obviously reduced when acute hypercapnia was administered in both normoxia and hyperoxia.Quantitatively, the decrease of CO2 content under hypercapnia corresponded to the difference in CO2 content between the true and separated plasma.The reduction, however, was slightly stronger in normoxia than in hyperoxia with alveolar PCO2 of 300 to 420mmHg.These data seem to support the following explanation: When venous blood was oxygenated in normoxic air with PCO2 higher than true venous, the inward CO2 diffusion was inhibited by the Haldane effect and the reversed diffusion after the oxygenation could also be disregarded during the contact time.Because the oxygenation was accelerated in hyperoxia and the direction of the CO2 diffusion was reversed earlier than in normoxia, the plasma CO2 content became higher in hyperoxia than in normoxia.View full abstractDownload PDF (1092K) -
Yoshikazu KAWAKAMI, Takashi YOSHIKAWA, Akira SHIDA, Yoshihide ASANUMA1981 Volume 31 Issue 3 Pages 357-368
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSVentilatory responses to hypoxia (A) and hypercapnia (S) were measured in 127 healthy men (105 males and 22 females) by a dual control system for regulating Pa O2 and Pa CO2 simultaneously and independently of each other.The subjects were classified into groups according to sex, age, family history, and genetics (twins).Mean values for A were 138±SD 93 liters/min·mmHg in group I (subjects without family history of chronic lung diseases) and 80±56 liters/min·mmHg in group II (sons of patients with chronic obstructive pulmonary disease or silicosis).The difference was highly significant (P<0.001).
Mean S were 1.11±0.39 liters/min·mmHg-1 in group I and 1.16±0.48 liters/min·mmHg-1 in group II.The difference was not significant. Mean values for A and S in the aged males (mean age-71.3 years) did not differ from those in 15 adult males (mean age=29.5 years) and 60 young twins (mean age=16.4 years).
In every respect of age, sex, familial factors, and genetics, A and S were not interrelated.Mouth occlusion pressure (P0.1) was measured during air breathing and it correlated neither with A nor S.
These results indicate 1) hypoxic and hypercapnic responses are not strongly related to each other, and 2) the aging process does not alter ventilatory responses to hypoxia and hypercapnia.View full abstractDownload PDF (1311K) -
Tohru SAWANOBORI, Akihiko HIROTA, Shiroh FUJII, Kohtaro KAMINO1981 Volume 31 Issue 3 Pages 369-380
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe absorption signals of a merocyanine-rhodanine dye in response to action potential were measured on the bullfrog atrium. Simultaneous recording of optical signals and membrane potential showed the same time course within 15 to 30 min after exposure to Ca2+-free solution.The action spectrum of the dye exhibited a triphasic pattern with a decrease in absorption between 530 and 600nm, an increase between 640 and 720nm and a decrease at 750nm.Using five photodetectors we have been able to simultaneously monitor the action potential from five different regions of the preparation.The conduction velocity could be measured even in Ca2+-free solution;the velocity measured optically by the simultaneous multi-recording method was equal to that obtained with a microelectrode measurement.Thus, the optical method can validly be used to solve some problems on arrhythmia-related mechanism.View full abstractDownload PDF (1188K) -
Masaya FUNAKOSHI, Kenji KAWAKITA, Takayuki MARUI1981 Volume 31 Issue 3 Pages 381-390
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe stimulating effect of taste substances on the external chemoreceptors of the carp, Cyprinus carpio L., was studied by recording the electrical activity from the facial taste fibers innervating the facial skin surface.The integrated responses from each whole nerve bundle of the trigemino-facial complex nerve revealed that gustatory receptors on the snout of the carp were extremely sensitive to salts, acids and the extract of silk worm pupae.Quinine-HCl and sucrose elicited relatively small responses.Responses occurred to several amino acids, and especially to betaine.The threshold concentration for both mono-and di-valent salts was estimated to be about 5×10-3M and that for acids about 10-4M. Single fiber analysis was performed on 77 preparations.According to responsiveness to the 4 basic chemicals, the fibers were classified into 5 types: type I, activated by one stimulus (22 fibers out of 77); type II by two (29); type III by three (11); type IV by four (13); and type V showing inhibition by quinine-HCl (2) as their notable feature. Single fibers responsive to several amino acdis, and the worm extract were found, among which the last was the most effective stimulus as shown in the whole nerve experiments.View full abstractDownload PDF (1121K) -
Mitsuo ANRAKU, Saburo HASHIMURA1981 Volume 31 Issue 3 Pages 391-401
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn the 4-aminopyridine (4AP) Ringer in which the concentration of 4AP is above 0.005mM, the frog muscle contracted repetitively by rapid cooling.This contraction was named AP-RCC.It took more than 20min for 4AP to show the full effect on the AP-RCC.During the AP-RCC action potentials of the muscle membrane which synchronized with the repetitive contractions were observed.Tetrodotoxin abolished the AP-RCC.In muscle pretreated with 400mM glycerol, no AP-RCC was obtained.During the AP-RCC no action potential of the nerve was seen. d-Tubocurarine abolished both the AP-RCC and the accompanying action potential of the muscle.Mn2+ and, to a lesser extent, Mg2+, inhibited both the AP-RCC and the twitch by indirect stimulation.The repetitive nerve stimulation which lasted long enough to exhaust acetylcholine at the nerve terminal abolished the AP-RCC. 4AP restored the contraction suppressed by dantrolene sodium.The AP-RCC was masked by caffeine rapid cooling contracture when the concentration of caffeine was high.
From these results, the AP-RCC is considered to be generated by acetylcholine release from the nerve terminal by the combined action of 4AP and depolarization during cooling.View full abstractDownload PDF (1271K) -
Yoshikazu HAYATSU, Isao KOSAKA, Masaaki TSUTSUURA, Torao NAGAI1981 Volume 31 Issue 3 Pages 403-415
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe flexor carpi radialis muscle (FCRM) of the frog was divided into phasic and tonic bundles, and the properties of the potassium contracture in the tonic bundle were examined.The potassium contracture was tonic and the contracture induced by K higher than 75mM consisted of the initial phasic component and of the following sustained component. Both components were abolished by the transverse tubule disruption. The curve relating the peak tension to the log [K] o (activation curve) started at about 15mM K and reached maximum at about 75mM K. By reducing [Ca] o, the activation curve shifted downward at higher [K] o, being little affected near the mechanical threshold.The time course of inactivation induced by 20mM K was slow and monophasic, and was markedly accelerated by reducing [Ca] o.The spontaneous relaxation of the contracture induced by high K was little affected by reducing [Ca] o.View full abstractDownload PDF (1153K) -
Tadao KISHIKAWA, Hiroshi KURIYAMA1981 Volume 31 Issue 3 Pages 417-422
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe membrane activity recorded from the circular muscle layer of the human Fallopian tube showed a unique pattern (slow potential changes), yet the hormonal and adrenergic influences appeared to be much the same as observed in the myometrium.Differences in electrical and mechanical activities, and also the sensitivity to catecholamines during the secretory or proliferative period were elucidated.View full abstractDownload PDF (683K) -
Miharu MIYAMURA, Taizo TSUNODA, Noriaki FUJITSUKA, Yoshiyuki HONDA1981 Volume 31 Issue 3 Pages 423-426
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSVentilatory response to CO2 in the Ama (Kachido) was determined by the CO2 rebreathing method in the beginning (March) and during (September) harvest season.It was found that mean slopes of the ventilatory response curve in March and September were 0.76 and 0.73 liters/(min⋅m2⋅mmHg), respectively, this difference being insignificant.View full abstractDownload PDF (470K) -
Yoshifumi TANAKA, Taketoshi MORIMOTO, Kenju MIKI, Hiroshi NOSE, Masao ...1981 Volume 31 Issue 3 Pages 427-431
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSWe developed an experimental method which enabled continuous determination of the circulatory blood volume, when the blood volume was subjected to alterations.The blood volume was modified by a servo system to control transfer of the blood between an external reservoir and the cardiovascular system.Possible applications of our method to the analysis of circulatory responses to blood volume changes is discussed.View full abstractDownload PDF (2939K) -
Syôiti KOBAYASI, Ken'ichi YAMAGUCHI1981 Volume 31 Issue 3 Pages 433-437
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe temperature coefficients of the fundamental central respiratory frequency (f0), cycle duration (TC0), and inspiratory duration (TI0) were estimated, and their values were 5.3, -5.3 and-2.7, respectively. These results suggest that the fundamental respiratory pacemaker is under the influence of some thermosensitive mechanisms or is thermosensitive by itself, while the mechanism controlling the inspiratory duration is unaffected by thermosensitive mechanisms.View full abstractDownload PDF (479K) -
Soichi YOSHIDA1981 Volume 31 Issue 3 Pages 439-443
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn a preparation consisting of the reversed ureter of the guinea pig, by field stimulation action potentials originating from nerve fibers and smooth muscle cells were recorded.The smooth muscle action potential was assumed to be due to excitation of the nerve fibers.View full abstractDownload PDF (4819K)
- |<
- <
- 1
- >
- >|