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Volume 30 (1980)
- Issue 6 Pages 815-
- Issue 5 Pages 671-
- Issue 4 Pages 491-
- Issue 3 Pages 313-
- Issue 2 Pages 143-
- Issue 1 Pages 1-
Volume 30, Issue 4
Displaying 1-14 of 14 articles from this issue
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Mamoru FUJIMOTO, Yutaka MATSUMURA, Noriko SATAKE1980 Volume 30 Issue 4 Pages 491-508
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSTwo kinds of pH-sensitive microelectrodes were constructed:
1) glass microelectrode with a pH-sensitive tip of 50-100 μm in length, and 2) antimony (Sb) microelectrode with a tip of 1-5 μm in outside diameter. Comparisons of the two were made on the change in the electromotive force (EMF) in response to various pHs and biological applicability.
The pH sensitivity (slope constant) at 20°C of the glass and Sb-microelectrodes averaged 51.7 and 51.9 (-mV/pH), respectively. Over the pH range of 2 to 9, both electrodes responded linearly to the change of pH. The pH-dependent EMF of the Sb-microelectrode was influenced by phosphate buffers, but not by Tris-HCl buffers. Though the glass microelectrode showed a linear response to all the buffers tested, its slope constant tended to be limited by the surface area of the pH-sensitive tip.
The stability of the EMFs was well within 1mV for 12hr with the glass microelectrode but more than 10mV with the Sb-microelectrode. On the other hand, the 95% response time was about 1min with the glass microelectrode, whereas it was less than a few seconds with the Sbmicroelectrode.
Blood pH was measured with the two electrodes and reasonable values were obtained with both methods, although the values by use of the Sbmicroelectrode were slightly higher than those of the other.
In view of the practical ease of manufacturing, maintenance and durability, the use of the Sb-microelectrode in biological measurement should also be re-evaluated, but several restrictions must be imposed on it.View full abstractDownload PDF (1924K) -
Yutaka MATSUMURA, Noriko SATAKE, Mamoru FUJIMOTO1980 Volume 30 Issue 4 Pages 509-528
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1) Antimony (Sb) microelectrodes with tips of 2 to 5 μm in outside diameter were constructed, and their electromotive forces (EMF) were tested in response to the pH of several calibration buffers. The data were compared with those of glass pH electrodes.
2) Increasing ionic strength (I) caused a significant deviation in pH readings of the Sb-microelectrode (ΔpHSb-Glass). The above salt effect was empirically given by
ΔpHSb-Glass=0.017-0.125I (I=0.09-0.22)
3) Even with the correction for ionic strength, the values of ΔpHSb-Glass were still dependent on the nature of calibration buffers employed. Among various buffers, Tris buffer [Tris (hydroxymethyl)-aminomethane, (TRAM)] had the least disturbance on the Sb-microelectrode, and bicarbonate had also relatively minor effect.
4) The pH value according to the Sb-electrode was caused to deviate considerably by phosphate.The effect of phosphate within the range of 1 to 67 mM can be predicted by
1/ΔpHSb-Glass=1+ (0.174/[PO4])
5) Like phosphate, BES [N, N-Bis (2-hydroxyethyl)-2-aminoethane sulfonic acid] also had a significant effect on the EMF of the Sb-microelectrode.
6) Upon consideration of the above facts, measurements of several biological fluids, such as those of the in vivo pH of intratubular fluid of bullfrog kidney were carried out with the Sb-microelectrode calibrated by 90 mM Tris buffer.
7) Thus, it was concluded that the Sb-microelectrode when properly calibrated could be used for the pH measurement of ultraminute amounts of biological samples.View full abstractDownload PDF (1927K) -
Shinichiro KOKUBUN, Masao NISHIMURA, Akinori NOMA, Hiroshi IRISAWA1980 Volume 30 Issue 4 Pages 529-540
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe rabbit atrioventricular (A-V) node, with dimensions of approximately 5×3 mm was dissected into 15 small specimens (0.5×0. 5mm). A majority of the specimens continued to discharge spontaneous action potentials, the action potential configuration being almost identical in different specimens. The amplitude (98 mV) and the maximum rate of rise of the action potential (11 V/sec) were similar to those recorded from the intact A-V node (amplitude 98 mV, maximum rate of rise of action potential 12 V/sec). In these small specimens, the “resting membrane potential (-44 mV)” was approximately 20 mV less negative than that in the intact A-V node preparation (-62 mV) before the dissecting procedure. The spontaneous discharge in these small A-V node specimens was attributed to the low resting membrane potential. The small specimen became inexcitable under the effects of blockers of is, though TTX had no significant effect on the action potential. The afterhyperpolarization was observed after cessation of the depolarizing current pulse. It is concluded that the slow inward current and the slow kinetics of the outward current contribute to the generation of the spontaneous A-V node action potentials as in the sinoatrial node.View full abstractDownload PDF (2927K) -
Keiichi YOSHIMURA, Eriko NEZU, Akiko CHIBA1980 Volume 30 Issue 4 Pages 541-560
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSParotid slices respond to norepinephrine with a rapid but transient accumulation of cyclic AMP. Continued exposure of the slices to norepinephrine results in a loss of responsiveness to subsequent application of norepinephrine (refractoriness or desensitization).Refractoriness could not be overcome by exposing the slices to a supramaximum concentration of norepinephrine. The suppressed response was clearly seen at 15 min after the first exposure to norepinephrine, but about 60 min were required for reaching complete suppression. The refractoriness also depended on the concentration of agonists, and their order of potency correlated well with their agonistic activity. The induction of desensitization was β-agonist specific, and was blocked by β-adrenergic blocking agents such as atenolol and alprenolol. The recovery from desensitization was observed by removing norepinephrine from the medium. The recovery was not evident until 15 min after washing the slices, but was nearly complete after 1 hr. Although parallel changes were observed between the initial increase in cyclic AMP level and the degree of desensitization by norepinephrine, the induction of desensitization does not seem to be mediated by cyclic AMP. The mechanism underlying this phenomenon does not appear to involve the activation of phosphodiesterase, the formation of an inhibitory substance in the medium or an increase in the rate of excretion of cyclic AMP. Changes in the ATP level by norepinephrine did not always correlate with the degree of refractoriness.No significant changes in the amount of [3H]-dihydroalprenolol binding were found in the membrane fraction prepared from the slices incubated with norepinephrine.These results suggest that the induction of desensitization may be mediated by modulating the coupling process between the receptor and adenylate cyclase.View full abstractDownload PDF (2190K) -
Yoshiaki HABARA1980 Volume 30 Issue 4 Pages 561-574
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe influence of extracellular Ca2+concentration, [Ca2+] o, on the secretory response to acetylcholine (ACh) was analyzed in isolated perfused rat pancreas.The decrease of [Ca2+] o strongly diminished the amylase output and pancreatic juice flow in response to continuous stimulation with 5×10-8M ACh. A quantitative relation was found between the amount of amylase released by 5×10-8m ACh and the [Ca2+] oover a range of 0.1-2.5 mM.The partial replacement of NaCl with LiCl produced a diminution in both amylase output and pancreatic juice flow. A quantitative relation existed between the amount of ACh-induced amylase release and the [Na+] o over a range of 86-157 mM.The partial replacement of KC1 with NaCl produced falls in both amylase output and pancreatic juice flow.Again, a quantitative relation existed between ACh-induced amylase release and [K+] o over a range of 1.0-5.6 mM. These results are compatible with the view that both the amylase output and the juice flow induced by 5×10-8 M ACh are proportional to the amount of carrier-Ca complex and that the inward movement of the complex may be linked closely to the activation of Na pumps on the pancreatic acinar cell.
A dose-response relation was found between the concentration of ACh and the amylase output.The relation was shifted to the left when 1 mU/ml cholecystokinin-pancreozymin (CCK-PZ) was added.A similar shift was observed when 1mU/ml secretin was added. These results support the view that ACh, CCK-PZ, and secretin may activate the common cellular process in stimulus-secretion coupling, although these secretagogues may severally act on the different receptor sites.View full abstractDownload PDF (1394K) -
Ryoji KAWASAKI1980 Volume 30 Issue 4 Pages 575-589
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1) Vascular perfusion of the isolated head of the carp wascarried out with physiological saline.Respiratory movement of the gillcovers and respiratory discharges of cranial motor nerves were recordedin the preparation.
2) Blood vascular vessels supplying the brain were anatomically investigated.Concentrations (electrolytes, O2, CO2, and glucose) andperfusing pressure of the saline were determined by reference to the usefulinformation already available in fish physiology.
3) The movement of the operculum could be maintained in regular respiratory rhythm for more than 34 hr.Efferent discharges of cranialmotor nerves also indicated that the respiratory rhythm generatorfunctioned normally.Interruption of perfusate flow always immediatelydisturbed the opercular rhythm and resulted in respiratory arrest.
4) In conclusion, vascular perfusion is indispensable for the main-tenance of breathing rhythm-generation in the isolated head of the carp;as the perfusate, the colloid-free physiological saline was found tenablefor the long-term preservation of brain function in the carp.View full abstractDownload PDF (1580K) -
Hiroshi KITASATO, Shuichiro SATO, Yoshinori MARUNAKA, Koichi MURAYAMA, ...1980 Volume 30 Issue 4 Pages 591-602
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSTo gain an insight into the mechanism of stimulation by insulinof Na efflux, the effect of high concentrations of internal Na on the inhibition by ouabain of Na efflux was compared to the inhibition by ouabainof insulin-stimulated Na efflux.The rate coefficient of 22Na efflux from “high-Na” muscle exposed to ouabain was lower than that from “lowNa” uscle exposed to ouabain.Similarly, the rate of net Na loss from the “high-Na” e which had been exposed to ouabain was lower thanthat from the “low-Na”muscle.findings indicate that Na transport units whose internal Na-binding sites have been occupied by Na issusceptible to ouabain.The insulin-stimulated Na efflux was inhibitedby ouabain to a larger extent than was the Na efflux from the controlmuscle, although the final level of the rate coefficient of 22 Na efflux fromthe muscle exposed to both insulin and ouabain was not always lower thanthat from the muscle exposed only to ouabain.The similarity betweenthe effects of ouabain in “high-Na” muscle and in insulin-preincubatedmuscle suggests that insulin increases the fraction of Na transport unitswhose internal Na-binding sites have been occupied by Na.View full abstractDownload PDF (1250K) -
Hiroshi KITASATO, Shuichiro SATO, Yoshinori MARUNAKA, Koichi MURAYAMA, ...1980 Volume 30 Issue 4 Pages 603-616
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe dependency of Na efflux on intracellular Na concentrationwas examined on sartorius muscles of Rana catesbeiana.In normalRinger, the rate coefficient of 22Na efflux is nearly proportional to theinternal Na concentration, i.e., Hill's coefficient in the dependency of Naefflux on internal Na concentration was around two.As long as insulin is present in the bathing solution, the rate coefficient of 22Na efflux retainsthe stimulated level.Insulin caused a leftward shift of the relationship between Na efflux and the logarithm of internal Na concentration, andconcomitantly decreased Hill's coefficient.A model of the coupling of Na transport and hydrolysis of ATP was proposed.The theoretical relation derived from this model accounted for these findings quitesatisfactorily.According to this model, insulin shifts as a cofactorthe equilibrium between dephosphorylated and phosphorylated states of carriers, whose Na binding sites are not occupied by Na, toward the phosphorylated state.View full abstractDownload PDF (1329K) -
Takakazu KOBAYASHI, Haruo SUGI1980 Volume 30 Issue 4 Pages 617-629
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe heat production of frog skeletal muscle during isometriccontraction was measured with an infrared radiometer at room temperature (23-26°C), attention being focused on the heat produced duringthe summation of twitches by two successive stimuli.When the amountof heat produced by the second stimulus was plotted against the cor-responding tension increment, the data points fell on two regressionlines of approximately the same slope except for the intermediate stimulusintervals.One regression line started from the origin, while the otherintersected the ordinate at about 1mcal/g.If a twitch was produced atvarious times after a 0.5 sec tetanus, all the data points on the heat versustension increment plot distributed around a single regression line startingfrom the origin.These results are explained by assuming that therelation between the tension-dependent heat and the tension incrementin a twitch produced after a preceding mechanical response remainsnearly constant irrespective of the stimulus interval, while the amountof tension-independent heat production varies depending on the timeafter the preceding stimulation.View full abstractDownload PDF (1231K) -
Taeko YAMADA1980 Volume 30 Issue 4 Pages 631-643
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe developmental change in rat taste sensitivity during theperiod from the 2nd to the 12th postnatal week was studied by recordingthe responses of the chorda tympani nerve to lingual stimulation by NaCl, LiCl, KCl, NH4Cl, HCl, quinine hydrochloride (Q-HCl), and sucrose.The threshold for all stimulants except sucrose was lower in the 3-week-old rats than in the 12-week-old ones.The order of the magnitudes ofthe normalized neural responses to the 0.1 M monochloride salts of thegustatory nerves was NH4Cl>NaCl=LiCl>KCl in the 3-week-old rats, and NaCl=LiCl>NH4Cl>KCl in the 12-week-old rats.The magnitude of the normalized responses to NH4Cl, HC1, and Q-HCl at nearly allconcentrations was greater at 3 weeks than at 12 weeks, while the magni-tude of the responses to NaCl and LiCl at high concentrations was lesserat 3 weeks than at 12 weeks.Changes in the gustatory sensitivity tovarious taste stimuli during development can be classified into the following two types:(1) sensitivity-decreasing type the magnitude of theresponse to NH4Cl, Q-HCl, and HCl was greatest during the first fewweeks and decreased thereafter, and (2) sensitivity-increasing typethe magnitude of the response to NaCl, LiCl, and sucrose showed anincrease accompanying the growth of rats from around the 2nd weekafter birth.View full abstractDownload PDF (1288K) -
Akira NISHIO, Seizaburo KANOH1980 Volume 30 Issue 4 Pages 645-653
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe pyrogenicity of E.coli endotoxin (lipopolysaccharide, LPS) was measured at both 25°C and neutral temperatures (Tn) in day -1 to adult rabbits. Intravenous inlection of endotoxin (0.5μg/kg) produced febrile response at Tn in day-1 rabbits, but not at 25°C. A similar response was observed when endotoxin was injected s.c.(1.0μg/kg) or intracisternally (0.0001μg/kg).The mean magnitude of the rise of rectal temperature increased with the advance of age.Propranolol abolished the endotoxin-fever in day 3 rabbits.The inhibitory effect of propranolol was incomplete in day 14 rabbits and was not seen in day 28 rabbits.The inhibitory effect of phentolamine was not observed in day 3 and day 28 rabbits, but the blocker reduced the febrile response in day 14 rabbits.No shivering activity was evident in day 3 rabbits after injection of endotoxin.In the day 7 and 14 rabbits, shivering was less significant and of shorter duration than in the case of day 28 rabbits. The endotoxin caused no significant decrease in ear skin temperature in day 3 rabbits.A decrease in ear skin temperature was observed in rabbits older than 14 days.Thus, pyrogenic sensitivity is apparent even in day-1 rabbits.The mechanism of the heat production underlying endotoxin-fever gradually shifted from the nonshivering thermogenesis mediated by catecholamines to shivering thermogenesis during the first month of life.View full abstractDownload PDF (804K) -
Toshihide SATO, Mitsutaka OHKUSA, Kumiko SUGIMOTO1980 Volume 30 Issue 4 Pages 655-658
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe mean diameter of myelinated afferent fibers from the taste disk located on the frog tongue was 5.5μm within the fungiform papillae and increased at a rate of 0.8μm/cm length of fibers.A gradual increase in conduction velocity of single afferent fibers from the taste disk was confirmed electrophysiologically.View full abstractDownload PDF (359K) -
Hisashi OGAWA, Jun KAISAKU1980 Volume 30 Issue 4 Pages 659-663
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSEighty-eight solitary tract nucleus neurons of anesthetized rats were recorded extracellularly, and investigated by the spike responses to stimulation of the three tongue afferents and the ipsilateral parabrachial nucleus.Among them, 21 neurons were found to receive antidromic invasions from the parabrachial nucleus.Moreover, they were mostly excited by stimulation of the nerves innervating the anterior tongue.View full abstractDownload PDF (470K) -
Hikaru SUZUKI, Hirosi KURIYAMA1980 Volume 30 Issue 4 Pages 665-670
Published: 1980
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn the electrophysiological studies of the smooth muscle cell of the mesenteric artery, we observed a massive release of noradrenaline from nerve terminals in K-free solution.The nature of K-free induced contraction is discussed in relation to the generation of miniature excita-tory junction potentials and drug actions.View full abstractDownload PDF (583K)
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