Showing papers by "Kyushu University published in 1971"
TL;DR: The analgesic effect of morphine-6-glucuronide was 3 to 4 times as potent and approximately 2 times as long in duration as that of morphine when injected subcutaneously when injected intracerebrally in mice, but morphine-3-glUCuronide had no effect.
Abstract: Pharmacological properties of morphine-3-glucuronide and morphine-6-glucuronide were studied in mice and compared with those of morphine. 1) The analgesic effect of morphine-6-glucuronide was 3 to 4 times as potent and approximately 2 times as long in duration as that of morphine when injected subcutaneously. Morphine-3-glucuronide, however, showed no analgesic effect even in a dose of 27.6mg/kg. 2) The analgesic effect of morphine-6-glucuronide was about 45 times as potent as that of morphine, when injected intracerebrally in mice, but morphine-3-glucuronide had no effect. 3) After intraperitoneal injection of morphine-6-glucuronide in rats, only conjugated morphine was detected in the brain by chromatographic examination but not free morphine. 4) Morphine-6-glucuronide was also antagonized by nalorphine though to slightly lesser degree than morphine. 5) Development of tolerance to morphine-6-glucuronide in analgesic effect was almost the same in degree as that to morphine. Cross tolerance between morphine-6-glucuronide and morphine was observed as well.
370 citations
182 citations
TL;DR: The findings obtained may provide the background for the possible presence of gastric cancer in patients who have a carcinoid syndrome and the term “diffuse argentaffinoma” is suggested.
Abstract: Histochemical examination for argentaffin cells in 382 gastric and 81 intestinal carcinomas was carried out, and revealed that 3.1% of gastric and 2.5% of intestinal carcinomas contained argentaffin cells as an integral element of the tumor. Occurrence of these specific cells was predominantly encountered among diffuse carcinoma of the stomach. A hitherto undescribed case of diffuse carcinoma of the stomach containing numerous argentaffin cells is reported, and the term “diffuse argentaffinoma” is suggested. The findings obtained may provide the background for the possible presence of gastric cancer in patients who have a carcinoid syndrome.
116 citations
TL;DR: In this paper, the crystal orientation of the extrudate was examined by X-ray techniques, and it was found that there was a preferential a-axes orientation parallel to the radial direction of the rod-shaped extrude.
Abstract: Transparent and highly oriented samples of high dimensional stability were obtained by extruding crystallised linear polyethylene through a tapered die at temperatures higher than 80° C and below the melting point. The crystal orientation of the extrudate was examined by X-ray techniques, and it was found that there was a preferential a-axes orientation parallel to the radial direction of the rod-shaped extrudate. Electron micrographs of the fractured surface of the extrudate revealed closely packed thin fibrils of diameters of about 300 A. Small angle X-ray scattering showed a long period of 200 to 300 A along the longitudinal direction of fibrils, depending on the extruding conditions. This fact suggests the existence of the lamellar structure in the fibrils.
98 citations
TL;DR: The development of the separated flow past a flat plate which was started from rest either impulsively or with uniform acceleration was investigated experimentally by using flow-visualization techniques.
Abstract: The development of the separated flow past a flat plate which was started from rest either impulsively or with uniform acceleration was investigated experimentally by using flow-visualization techniques The flow is irrotational initially The onset of separation takes place at the two edges of the plate The symmetrical twin-vortices are always formed at small times no matter how large the Reynolds number may be The length of the wake bubble is nearly proportional to ( U t / d ) 2/3 or ( a t 2 / d ) 2/3 at small values of (ν t / d 2 ) (where U is the plate speed, t the time from the start, d the plate length, a the acceleration and ν the kinematic viscosity) The length of the symmetrical wake bubble exceeds 41 plate lengths at a d 3 /ν 2 =42×10 2
88 citations
TL;DR: A comparative study was made of 800 Japanese and 627 American cases of gastric carcinoma which had been surgically resected to show if there was a difference in histologic appearance associated with geographic distribution and incidence.
Abstract: A comparative study was made of 800 Japanese and 627 American cases of gastric carcinoma which had been surgically resected. The intention was to show if there was a difference in histologic appearance associated with geographic distribution and incidence. In both Japan and the United States adenocarcinoma was the predominant tumor type among the patients over 50 years of age. In patients under 50. years, the predominant tumor was diffuse carcinoma. The proportion of adenocarcinoma to diffuse carcinoma studied in age group from both populations showed no significant statistical difference in the proportionate number of each type. In the high incidence population of Japan, there was a predominance of younger patients, which contained a predominance of diffuse carcinoma.
57 citations
TL;DR: The development of the intrahepatic bile ducts of the human fetus was investigated by light and electron microscopy and the fine structure of the developing liver cells and biliaryduct cells is described.
Abstract: The development of the intrahepatic bile ducts of the human fetus was investigated by light and electron microscopy. Bile canaliculi with microvilli and junctional complexes are already found in the embryo of 7 mm. Some of them are of the intracellular type. At six to seven weeks, large bile canaliculi bounded by four to seven liver cells appear. Subsequently, bile canaliculi are formed predominantly between three to four adjoining liver cells and this arrangement persists throughout later fetal life. The early intrahepatic bile ducts develop around the portal vein as epithelial cell plates derived from the hepatic duct and the branches sprout from the epithelial cell plates in several different places. The epithelial cell plates are separated from each other by primitive connective tissue and they change into a complex network of bile ducts. Formation of the intrahepatic bile ducts is completed by three months. Biliary duct cells at the end of the developing bile ducts are thought to transform into liver cells. Therefore, at the ducts of Hering various transitional cells appear between biliary duct cells and liver cells. The fine structure of the developing liver cells and biliaryduct cells is also described.
55 citations
TL;DR: In this paper, the wave functions of the 1S (ground state), 3P and 1P states for the beryllium isoelectronic sequence have been obtained in various approximations.
Abstract: Wave functions of the 1S (ground state), 3P and 1P states for the beryllium isoelectronic sequence have been obtained in various approximations.
The HF2p orbitals for the 1P and 3P states are similar except for Be, where the 2p orbital is quite diffuse for the 1P state.
The difference between the experimental E(1P) – E(3P) and the HFE(1P) – E(3P) is 0.62 eV for Be and 1.17 ∼ 1.40 eV for B+ ∼ F5+. The disagreements are attributed to the correlation effects between the 2s and 2p electrons. This is confirmed by ci calculations.
It is shown that a limited basis SCF calculation reproduces the above feature of the HF results if we treat the orbital exponents as the variational parameters. The use of the Slater values for the orbital exponents is shown to be inadequate especially for the Be 1P state.
The conclusions of this paper will be useful for discussing the V–T separations of H2 and C2H4.
53 citations
TL;DR: Plasma levels of tryptophan were observed in the fasting state and after oral administration of l -tryptophan in normal subjects and in patients with chronic liver disease, and in cirrhosis patients under treatment by microsomal enzyme inducers.
51 citations
TL;DR: It was concluded that the smooth muscle of the bladder possesses cableproperties and the electrical activity is similar to other mammalian visceral smooth muscles.
Abstract: 1.
Smooth muscle cells of the guinea-pig urinary bladder, studied with micro-electrodes, had a mean resting potential of −37.3 mV.
2.
Spontaneous action potentials could be recorded in normal Krebs solution and in Krebs solution made hypertonic with sucrose. These occurred at regular intervals or in bursts. Slow waves were recorded only occassionally in normal Krebs solution.
3.
The amplitude of spikes was variable but spikes with overshoots of over 20 mV were often seen. The maximum rate of rise was 4.2 V/sec for spikes of 60 mV.
4.
The chronaxie was 90–120 msec and the mean conduction velocity of evoked spikes was 41.2 mm/sec.
5.
The amplitude of the electrotonic potential was linearly proportional to the current applied to one end of the tissue. The decay of the electrotonic potential along the tissue was exponential, with a mean length constant of 1.7 mm.
6.
The time constant of the membrane calculated from the electrotonic potential (127 msec) was approximately the same as that calculated from the conduction velocity, length constant and time course of the foot of the spike (122 msec).
7.
It was concluded that the smooth muscle of the bladder possesses cableproperties and the electrical activity is similar to other mammalian visceral smooth muscles.
49 citations
TL;DR: It is postulated that background inward currents, responsible for generating the low voltage oscillation, are carried by both Ca and Na ions which pass through a probable “slow channel, ” which is activated at a membrane potential of about-50mV in normal Tyrode solution.
Abstract: 1. The membrane potential of Purkinje fibers excised from the left ventricle of the dog heart was changed to various potential levels using the partition chamber method.2. The existence of pacemaker activity of two kinds which are due to different mechanisms was suggested in Purkinje fibers: one is a natural pacemaker activity at high membrane potentials and the other, oscillations at membrane potential below about-60mV.3. The natural pacemaker activity is strongly dependent on extracellular Na ions but little affected by changes in extracellular Ca ions except for an indirect action resulting from a change in the threshold potential.4. On the other hand, the spontaneous repetitive discharges (oscillations) at low membrane potential depend markedly on extracellular Ca concentration but only slightly on Na ions.5. It is postulated that background inward currents, responsible for generating the low voltage oscillation, are carried by both Ca and Na ions which pass through a probable “slow channel, ” which is activated at a membrane potential of about-50mV in normal Tyrode solution.
TL;DR: Evidence is presented suggesting that an endonuclease activity against methylmethane sulfonate-treated DNA found in a crude extract of this organism may be attributable to another class of enzyme different from the endonuklease active on ultraviolet-irradiated DNA.
TL;DR: Results indicate that lipopolysaccharide is affected by polymyxin functionally and morphologically, but lipoprotein is not, while phage T2 adsorbed irreversibly to the normal smooth surface between the projections on the outer layer caused by the drug treatment.
Abstract: Treatment of gram-negative bacteria with lethal doses of polymyxin B and colistin resulted in the formation of projections of the outer layer of the cell wall. Phages T3, T4, and T7, which use wall lipopolysaccharide as receptors, were specifically prevented from adsorbing to Escherichia coli B cells treated with polymyxin, whereas phages T1, T2, T5, and T6 were not. In the systems of phage P22C-Salmonella typhimurium LT2 and phage C21-S. typhimurium variant SL1069, the phage were prevented from adsorbing to the host cell treated with the antibiotics. Electron microscopic observations show that phage T2 adsorbed irreversibly to the normal smooth surface between the projections on the outer layer caused by the drug treatment. These results indicate that lipopolysaccharide is affected by polymyxin functionally and morphologically, but lipoprotein is not. The purified lipopolysaccharide showed a ribbon-like structure when viewed face on and showed trilamellar structure when viewed edge on. The lipopolysaccharide from E. coli B was irreversibly adsorbed by phages T3, T4, and T7, but not phage T2. Often, phage T4 adsorbed to both sides of the lipopolysaccharide strand at comparable distances. Phage P22C adsorbed through the spikes of the tail-plates to the lipopolysaccharide from S. typhimurium LT2. Lipopolysaccharide which was treated with low doses of the drug (2.5 to 6.25 mug of polymyxin B per ml to 100 mug of lipopolysaccharide per ml) turned into the coiled form and was partially broken down into short segments with coiled form. The loosely coiled lipopolysaccharide retains both its function as the receptor and its trilamellar structure. Treatment with high doses of the drug (12.5 to 25 mug of polymyxin B per ml to 100 mug of lipopolysaccharide per ml) caused the collapse of the trilamellar structure of the strand. These collapsed lipopolysaccharides became flat and fused with each other, making an amorphous mass, and finally they were broken into small collapsed fragments.
TL;DR: Three nutritively significant enediol compounds can inhibit sarcoma-180 growth and are briefly discussed in relation to metabolic carcinostasis and to the formulation of Yamafuji effect causing cellular differentiation and anomalization.
Abstract: Three nutritively significant enediol compounds mentioned in above title can inhibit sarcoma-180 growth. The inhibition by ascorbic acid is enhanced by cupric ions. These enediols depolymerize DNA, particularly in co-operation with copper. Dehydroascorbic acid is able to break denatured DNA and to bring about single strand scission for native one. A mixture of dehydroascorbate and Cu decomposes apurinic acid and liberates deoxy-cytidylic acid from it. Only the oligo-form pf pyrimidine tetra- and penta-nucleotides is disintegrated by this reagent. The results were briefly discussed in relation to metabolic carcinostasis and to the formulation of Yamafuji effect causing cellular differentiation and anomalization.
TL;DR: In this article, the anomalous part of the attenuation at the resonance field position, Δ α, obeys the law Δ α= A (T / T c -1) -(0.49±0.06) in a limited region of reduced temperature (T/T c - 1).
Abstract: A new phenomenon in sound attenuation in bismuth has been observed at liquid helium temperatures and under very strong magnetic-field conditions such that the electrons and holes in the states with the Landau quantum number n =1 almost simultaneously satisfy resonance when varing the field strength in some suitable field directions. The anomalous part of the attenuation at the resonance field position, Δ α, obeys the law Δ α= A ( T / T c -1) -(0.49±0.06) in a limited region of reduced temperature ( T / T c -1). The values of the parameters T c (\({\lesssim}1.6\) K) and A depend characteristically on the difference between the resonance field strengths for the electrons and holes. The experimental facts suggest that this phenomenon may be related to the fluctuation of electron-hole pairs produced above the excitonic phase transition temperature.
TL;DR: The effects of caffeine (0.2–10 mM) on the electrical and mechanical activities of guinea pig taenia coli were investigated with the double sucrose-gap method and NO3 - and Br- showed a similar response to caffeine on the potentiation of the twitch tension at low temperature.
Abstract: The effects of caffeine (0.2–10 mM) on the electrical and mechanical activities of guinea pig taenia coli were investigated with the double sucrose-gap method. Caffeine evoked a small tension with a latency of 20–30 sec, then phasic contraction developed and finally relaxation. The initial tension development also appeared in the Na-free solution without any marked changes in the membrane potential and membrane resistance. The phasic contraction disappeared in the Na-free solution. The relaxation in the presence of caffeine was accompanied by depolarization block of the spike generation. The minimum concentration of Ca ion needed to evoke the tension development by the caffeine was 10-7 M. Caffeine also potentiated the twitch tension below a concentration of 5 mM either in the Na-free solution or at low temperature (5°C). NO3- and Br- showed a similar response to caffeine on the potentiation of the twitch tension at low temperature.
TL;DR: In a systematic screening survey for abnormal haemoglobins, a new variant named Hb Miyada is discovered which may possess a fused non-α-chain, and is likely to be of anti-Lepore type.
Abstract: SEVERAL slow-moving abnormal haemoglobins associated with thalassaemia-like stigmata have been encountered during the past 13 yr1–6 The non-α-chains of these haemoglobins are the fusion products7 of δ and β-chains; the N-terminal end containing a part of the β-chain joined to a fragment of the β -chain ending in the C-terminal But no structural variants of anti-Lepore type (fused in reverse β-δ) have yet been demonstrated In a systematic screening survey for abnormal haemoglobins8, we discovered a new variant named Hb Miyada which may possess a fused non-α-chain
TL;DR: In this article, the role of the metal ion in the oxidation of olefins was explored by an ordinary flow reactor in order to explore the role the ion in olefin.
TL;DR: Increase in [Ca++] abolished spontaneous action potentials in the guinea-pig urinary bladder and increased the amplitude and rate of rise of evoked spikes and decreased the amplitude without affecting the resting membrane potential.
Abstract: 1.
Increase in [Ca++] abolished spontaneous action potentials in the guinea-pig urinary bladder and increased the amplitude and rate of rise of evoked spikes.
2.
In Ca-deficient solutions, the membrane was depolarized and action potentials occurred in bursts, often terminating in a sustained depolarization.
3.
Substitution of NaCl with sucrose (1/10 Na+ remaining as NaHCO3) produced transient hyperpolarization followed by return to the original level. The amplitude and rate of rise of spikes were progressively reduced.
4.
Substitution with tris chloride produced depolarization and increase in membrane resistance. The rise time of the spike was prolonged but the amplitude was only slightly reduced. On addition of Ca++ to 4 x the resting potential was restored and rise time reduced.
5.
Addition of Mn++ to normal Krebs or 1/2 Na+ (tris) Krebs prolonged the action potential and decreased the amplitude without affecting the resting membrane potential.
6.
The electrical activity was unchanged in the presence of tetrodotoxin (2×10−7 g/ml).
7.
The frequency of spontaneous spikes was decreased by adrenaline or noradrenaline (5×10−5 g/ml) and increased by acetylcholine (1×10−7 g/ml). Nicotine (1×10−4 g/ml) produced a slight increase in frequency. Atropine completely blocked the action of acetylcholine.
TL;DR: The results reported below indicate that in this species also the B's accumulate in the germ line.
Abstract: morpha bedeli (Sannomiya and Kayano, 1969), Calliptamus palaestinensis (Nur, 1963), Cainnula pellucida (Carrol, 1920; Nur, 1969), Gonista bicolor (Sannomiya, unpublished), Locusta migratoria (Itoh, 1934; Rees and Jamieson, 1954; Nur, 1969), J'Teopodismopsis abdominalis (Rothfels, 1950), and Patanga japonica (Sannomiya, 1962). Nur (1963) suggested that mitotically unstable B's were maintained in association with an accumulation mechanism. This suggestion has been verified in Camnula pellucida, in which a higher mean number of B's is found in meiocytes than in cells of the gastric caeca (Nur, 1969). In the case of C. pellucida, however, the meiocytes and the cells of the gastric caeca were studied in different individuals. Of course, the best procedure is to establish the number of B's in the meiocytes and the cells of the gastric caeca using the same individual. This procedure has been utilised in Locusta migratoria, and the results reported below indicate that in this species also the B's accumulate in the germ line.
TL;DR: The effect on pregnant mouse of removing external Na was investigated by substituting sucrose, Tris, choline, and Li for Na and the relationship between the amplitude of the action potential and the membrane potential, which was displaced by external current application, was investigated.
Abstract: 1. The effect on pregnant mouse of removing external Na was investigated by substituting sucrose, Tris, choline, and Li for Na. The membrane potential as well as the spike potential were not noticeably changed by a reduction of external Na to half (69mM Na) in Krebs solution. Although a reduction of Na to 15.5mM produced a slight depolarization, the amplitude of the action potentials was little affected. Reducing external Na to less than 5mM or to zero produced a prompt and sustained depolarization to-25mV, with cessation of spike activity and contracture. These observations are contrary to those expected from the Goldman equation.2. Spike potentials were evoked by conditioning hyperpolarization for about 20 min in a Na-free solution. These then gradually diminished and eventually disappeared in 40min. Spontaneous spikes, which were abolished in Na- and Ca-free solution, reappeared upon subsequent addition of Ca (2.5mM).3. The relationship between the amplitude of the action potential and the membrane potential, which was displaced by external current application, was investigated in normal and in low Na solutions. The relationship was S-shaped, with the amplitude of evoked action potentials decreasing at high membrane potentials. Its implication was discussed.4. It was speculated that reduction of external Na inhibited the extrusion of Ca from the cell, hence producing a contracture in Na-free solution. Removal of external Na would therefore depolarize the membrane by changing the distribution of Ca across it. Alternatively, reduction of intracellular Na in Na-free solution may depress the electrogenic Na pump.
TL;DR: Differences in characteristics of the bullfrog ventricle from those of mammalian myocardium were discussed, and a role of sarcotubular systems in the relation between the action potential and tension development was suggested.
Abstract: 1. The membrane potentials, currents and contractile responses were measured in the bullfrog ventricular trabeculae under voltage clamp conditions by means of double glycerol-gap technique.2. The threshold potential for sodium inward current was -62mV and that for tetrodotoxin insensitive current, -58mV. At stronger depolarization up to +20mV, the contractile tension increased, showing a sigmoid curve in the presence of tetrodotoxin.3. The tension development depended strongly on the duration of depolarization. Below a critical duration, neither active current nor tension was elicited (Phase I). Slightly longer depolarization, up to about 100msec, produced an all-or-none inward current and small tension in normal conditions (Phase II). This changed into graded responses after tetrodotoxin.4. Further increase in duration of depolarization augmented the peak tension, first by increasing the rate of rise of tension (Phase III) and later by prolonging the time to peak tension (Phase IV). After reaching the peak the tensionde creased gradually when the depolarization was continued further (Phase V). No second rise of tension was observed for long and strong depolarizations.5. Differences in characteristics of the bullfrog ventricle from those of mammalian myocardium were discussed, and a role of sarcotubular systems in the relation between the action potential and tension development was suggested.
TL;DR: In this paper, the metal chelates of o-phenanthroline, a, a′-dipyridyl or bathophenanthroine were used as the ion exchanger in the liquid membrane of the perchlorate ion-selective electrode.
Abstract: The metal chelates of o-phenanthroline, a, a′-dipyridyl or bathophenanthroline were used as the ion exchanger in the liquid membrane of the perchlorate ion-selective electrode. The electrode with a nitrobenzene membrane containing tris(bathophenanthroline)ferrous perchlorate is the highest sensitive one and gives a linear Nernstian response up to about 1 × 10 −5 M perchlorate. The membrane electrode having the ferrous ion-chelate of o-phenanthroline as an ion exchanger shows an excellent selectivity for perchlorate ion over nitrate or iodide Ion. The effects of the chelate concentration in the membrane and the central metal species of the chelate are examined on the electrode performance.
TL;DR: Intercellular junctions in arterial smooth muscle have been examined and Junctions between areas of the surface membrane from the same cell are described and some implications of this finding are discussed.
Abstract: Specialized areas of close apposition (nexuses) are found between the smooth muscle cells of various organs (Dewey and Barr, 1962, 1964), including blood vessels (Cliff, 1967 ; Verity and Bevan, 1968; Devine and Simpson, 1968) . The nexus may appear as either a tight junction, with apparent membrane fusion, or a gap junction, possibly depending on the method of fixation (Brightman and Reese, 1969 ; and compare Cobb and Bennett, 1969 a with Uehara and Burnstock, 1970). These structures may be important in the conduction of electrical events which is known to occur between smooth muscle cells of various organs (Bozler, 1938 ; Tomita, 1967 ; Barr et al ., 1968; Abe and Tomita, 1968) . In addition, conduction between arterial smooth muscle cells is suggested by the successful use of the sucrose-gap method to record from this tissue (Keatinge and Richardson, 1963 ; Keatinge, 1964) . In the present work, intercellular junctions in arterial smooth muscle have been examined . Junctions between areas of the surface membrane from the same cell are also described and some implications of this finding are discussed .
TL;DR: The sensitized tanned red cell haemagglutination, passive cutaneous anaphylaxis and gel diffusion techniques showed that formalin-treated rabbit dental pulp maintained a strong cross-reactivity with untreated (native) tissue.
TL;DR: In this paper, the anomalous growth of the peak value of the lower field side attenuation coefficient due to electrons and holes lie close as a function of magnetic field was attributed to the fluctuation of the order parameter of excitons above the critical point T c, which is around 1 K.
Abstract: Anomalous behaviors of the ultrasonic attenuations in Bi under strong magnetic fields found by Mase et al. are analyzed by taking account of the excitonic instability. Characteristic features of anomalous growth of the peak value of the lower field side, in the case where the two peaks of the attenuation coefficient due to electrons and holes lie close as a function of magnetic field, can be attributed to the fluctuation of the order parameter of excitons above the critical point T c , which is around 1 K. Critical exponent of the excess contributions from the fluctuation to the attenuation coefficient is one half, which is in accordance with the experiments.
TL;DR: Effects of externally applied noradrenaline and isoprenaline on the electrical and mechanical activities of the guinea-pig was deferens and the relationships between the membrane potential and tension development were observed using the microelectrode and double sucrose gap methods.
Abstract: Effects of externally applied noradrenaline and isoprenaline on the electrical and mechanical activities of the guinea-pig was deferens were observed using the double sucrose gap method. 1. Noradrenaline (10-8-10-5g/ml) depolarized the membrane, reduced the membrane resistance, produced spike generation and brought about contraction (a-response). These effects were suppressed by treatment with phentolamine (10-6-10-5g/ml). 2. The a-response is caused by increased Na and K conductances, and probably by increased Ca conductance also. The Cl ion reduced the a-response due to high conductance of the membrane. 3. Isoprenaline (10-7-10-8g/ml) neither depolarized the membrane nor changed the membrane resistance but reduced the amplitude of the phasic contraction (8-response) evoked by an outward current pulse. The suppression of the contraction was blocked by treatment with propranolol (10-6g/ml). 4. Ouabain (10-6g/ml) depolarized the membrane, reduced the membrane resistance and increased the spike frequency. Under the above conditions, effects of catecholamines were not suppressed. 5. The relationships between the membrane potential and tension development were observed using the microelectrode and double sucrose gap methods. The amplitudes of the phasic response of the contracture were closely related to membrane potential levels displaced by excess K ion, but the amplitudes of the tonic response were not related. 6. In excess K-Krebs solution (below 59mM), noradrenaline (10-710-6g/ml) and isoprenaline (10-7-10-6g/ml) were similar to those observed in 5.9mM K-Krebs. When external Na ion was removed, however, the effects of noradrenaline and isoprenaline were absent. 7. If K-Krebs solution was in excess (above 59mM), the amplitude of the tonic response of the contracture was less than 20% of the amplitude