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Volume 26 (1976)
- Issue 6 Pages 577-
- Issue 5 Pages 441-
- Issue 4 Pages 345-
- Issue 3 Pages 235-
- Issue 2 Pages 101-
- Issue 1 Pages 1-
Volume 26, Issue 5
Displaying 1-8 of 8 articles from this issue
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Tohru YOSHIOKA, Keiko KAWAI, Yasuji KATSUKI1976 Volume 26 Issue 5 Pages 441-453
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe stimulating effct on the receptor organ of various monoand divalent metallic ions on the lateral-line nerve of tadpoles was studied. The orders of the effectiveness were Ag+>Tl+>K+=Na+>Li for monovalent ions and Sr2+>Mg2+≥Ba2+>Cd2+≥Co2+>Mn2+>Zn2+ for divalent ions.Both agree well with the order of Pearson's softness parameter for monovalent ions and Edwards'modified parameter for divalent ones.
All sorts of divalent cations exhibited suppressive effects on the stimulating effect of the monovalent cations when they were applied together with the monovalent cations.
A simple selection rule was found for the suppressive effect. The stimulating effect of Na+ or K+ was suppressed by all sorts of divalent cations. But the effect of Ag+ was suppressed by Cd2+, but not by Mg2+ nor by Ca2+.
In order to remove the Ag+effect, a dilute solution of DTT was used, although the effect of K+ or Na+ was removed easily by rinsing with distilled water.
From these results the receptive mechanism of the endorgan was thought to be chemical adsorption of ions in the receptor cell membrane. Based on the principle of “hard and soft acid and base”, it is suggested that there are two types of binding sites for the ions on the membrane, a soft site and a hard one.View full abstractDownload PDF (1362K) -
Tomio SHINGAI, Kyuhachiro SHIMADA1976 Volume 26 Issue 5 Pages 455-469
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSWater and various chemical solutions were applied to the oral cavity, pharynx, and larynx of anesthetized rabbits to study their effects on the swallowing reflex. Laryngeal stimulation: Water was an effective stimulus in eliciting reflex swallowing;NaCl depressed this reflex. The effect of salt solutions on swallowing was dependent on anion species. Weakly hydrated anions had a depressing effect while greatly hydrated anions had a facilitating effect.The order of the depressing effect of the anions was Br-> SCN->Cl-=NO3- and the order of the facilitating effect of anions was citrate> SO42-> HCO3-.
Oral and pharyngeal stimulation: Water elicited swallowing;however, this effect was less marked than that in the larynx. NaCl in concentrations lower than 200mM had a depressing effect while at higher concentration it had a facilitating effect. Sucrose, acetic acid, and alcohol evoked successive swallowing movements. Quinine facilitated the initiation of swallowing in the first two or three trials.
It was found that water applied to the laryngeal region had the marked effect of eliciting redlex swallowing and that most gustatory substances infused into the oral and pharyngeal regions had a facilitating effect on the initiation of swallowing.View full abstractDownload PDF (1588K) -
Tadasi SATO, Makoto SATO, Masashi SAWADA1976 Volume 26 Issue 5 Pages 471-485
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThree kinds of the cholinoceptive neurons, nicotinic depolarizing (D)-, nicotinic hyperpolarizing (H)-, and muscarinic H-types, as well as two other kinds of neurons, GABA H-and dopamine H-types, were identified in Aplysia abdominal ganglion, and the effects of disulfide bond reduction and reoxidation on their postsynaptic responses were studied by measuring conductance change produced by each transmitter. The acetylcholine-induced responses of both nicotinic types (D-and H-) were depressed by reducing the disulfide bonds witn aitniotnreitol (DTT) and restored by reoxidizing with 5, 5'-dithiobis-(2-nitrobenzoic acid):(DTNB), whereas the responses of the muscarinic H-, GABA H-, and dopamine H-cells were not affected at all by either DTT or DTNB.
In contrast to the results obtained from the electroplax, the cholinergic receptors in our preparation showed neither the activation by hexamethonium nor the augmentation of decamethonium-induced responses after reduction of disulfide bonds.In addition, our preparation did not demonstrate the long-lasting responses to bromoacetylcholine, which was often observed in the electroplax after reduction of S-S bonds.
DTT-induced depression of the nicotinic responses was studied on the dose-response curves; the mode of receptor inhibition was rather comnlexed. being neither tvae of competitive nor non-competitive.
We concluded that the disulfide bond is a crucial element in both types of nicotinic receptors (D and H), and that this bond is related to the activation process of the receptors regardless of their ionic specificities.View full abstractDownload PDF (1489K) -
Satoshi KURIHARA, Toshio SAKAI1976 Volume 26 Issue 5 Pages 487-501
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe relationships between the effects of procaine and those of Ca on the spontaneous electrical and mechanical activities of smooth muscle cells of the guinea pig urinary bladder were studied using both microelectrode and sucrose gap methods. Procaine (1, 7, and 15 mM) depolarized the membrane and increased spontaneous spike frequency. The maximum rates of rise and fall and the after-hyperpolarization of the spike decreased. Enhanced spontaneous rhythmic contractions accompanied these membrane activities (1 mM). The tone of the preparation (resting tension) increased transiently and decreased gradually (7-15 mM). These procaine effects were suppressed by the application of excess Ca (7.5 mM). The increased electrotonic potential induced by 7 mM procaine was reduced by the addition of 7.5 mM Ca. Reduction of Ca concentration (0.8 and 0 mM) in Krebs solution containing procaine further depolarized the membrane and decreased the spike amplitude. In Ca-deficient solution, the enhanced rhythmic contractions induced by procaine were slightly reduced.
Compound D600 (1-3mg/1), manganese ion (Mn)(1-3 mM), and cobalt ion (Co)(1-3 mM) inhibited the effects of procaine on spike discharges and mechanical responses.
From these results it is concluded that procaine action is related to that of Ca which controls the membrane permeability, since procaine depolarizes the membrane by reducing K conductance. Furthermore, action potentials observed in the Krebs solution containing procaine are considered to be Ca spikes, which seem to play an important role in excitation-contraction coupling in the guinea pig urinary bladder smooth muscle.View full abstractDownload PDF (1553K) -
Satoshi KURIHARA, Toshio SAKAI1976 Volume 26 Issue 5 Pages 503-516
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSModification of the effects of K, Ca, acetylcholine and rapid cooling by procaine were examined in the smooth muscle of the guinea pig urinary bladder. Contraction enhancement by procaine was observed in 5.9mM K-and 23.6mM K-Krebs solutions but was not confirmed in 59mM K solution. Procaine enhanced contraction in relation to membrane activities. Relationships between membrane potential and K concentration showed that procaine reduced K conductance. This effect decreased as K concentration increased. K-induced contracture was inhibited by procaine at 37°C and 10°C. Procaine inhibited Ca-and acetylcholine-induced contractions in isotonic K2SO4-Locke solution. Rapid cooling contracture, initiated by lowering the temperature of the solution from 36±1°C to 12±2°C within 30 sec, was inhibited by procaine.
From these results, it is concluded that procaine has an inhibitory effect on Ca permeation through the cell membrane and on Ca release from sequestered sites, and it is confirmed that procaine enhancement of spontaneous contractions is related to the spike activity resulting from depolarization which is caused by reduction of K conductance (KURIHARA, 1975). The mechanism of the procaine effect is discussed in relation to excitation-contraction coupling in the guinea pig urinary bladder.View full abstractDownload PDF (1333K) -
Tokuo OGAWA1976 Volume 26 Issue 5 Pages 517-528
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe effects of a small dose (3-6μg/kg) of subcutaneously administered adrenaline on thermal sweating were studied while subjects were at rest and during or after exercise by means of continuous monitoring by resistance hygrometry of the sweat rate in the forearm area.In most cases, the sweat rate either decreased or did not change significantly following the adrenaline injection, however, among athletic subjects it showed a mild increase in a few cases, mostly during or after exercise. In the area receiving the intradermal injection of an α-adrenergic blocking agent, tolazoline, phentolamine or dihydroergotoxine, subcutaneous adrenaline consistently caused an increase in sweat rate. Adrenaline (15 μg) was injected intravenously with similar results. Noradrenaline was used in place of adrenaline in some cases, and the results were essentially the same as, but less distinct than, those with adrenaline. The results indicate that a small dose of subcutaneous adrenaline has dual effects, with the sweat-inhibitory effect generally predominating over the sweat-facilitatory one, with occasional exceptions in association with exercise and/or physical training. The former effect is largely secondary to its vasoconstrictive effect, whereas the latter appears to be secondary to its systemic effects, such as central and calorigenic ones. It is concluded that adrenaline within a physiological range exerts no direct action on human eccrine sweat glands.View full abstractDownload PDF (1446K) -
Pawan K. SINGAL, Kailash PRASAD1976 Volume 26 Issue 5 Pages 529-535
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe role of extracellular calcium in the positive inotropic effbct of X537-A in dog's cardiac muscle was investigated.Ionophore (20 μg/ml) in the presence of external calcium increased the contractility by 67±12 percent within 2 min. In the absence of external calcium ionophore was ineffective in producing a positive inotropic effect in the muscle. Lanthanum, an inhibitor of calcium influx, in the concentrations of 2, 4, 6, and 8 mM produced a concentration dependent decrease in the contractility. Ionophore-induced increase in the contractility was inversely related to the concentration of lanthanum used. It is suggested that the release of calcium from intracellular stores under the effect of ionophore is not enough to maintain contractility. Also positive inotropic effect of ionophore appears to be mediated through the transportation of calcium across the sarcolemma. Such ionophore mediated transportation of calcium appears to be dependent upon surface binding of calcium.View full abstractDownload PDF (631K) -
Kazuo MISHIMA, Hirosi KURIYAMA1976 Volume 26 Issue 5 Pages 537-548
Published: 1976
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSEffects of prostaglandin E1, E2, and F2α (PGE1, PGE2, and PGF2α) on the electrical and mechanical properties of the smooth muscle of various areas of the guinea pig stomach were investigated.
PGE1 and PGE2 (10-9-10-6g/ml) suppressed the spontaneously generated mechanical activity in circular muscle of the pylorus, but increased the activity of muscles in other areas of the stomach, while PGF2α (10-9-10-6g/ml) showed excitatory action on muscles in all the areas of the stomach. These PG actions on the stomach muscle were mainly myogenic responses, and were not affected in the presence of tetrodotoxin (10-7g/ml). PGE1 and PGE2 (10-8-10-6g/ml) hyperpolarized the membrane and suppressed the generation of slow potential change in the circular muscle of the pylorus, thus causing the cessation of spikes which were superimposed on the slow potential change. On the other hand, these agents depolarized the membrane and increased membrane activity in the longitudinal muscle of the pylorus and both layers of the corpus. When voltage-current relationships were observed before and during application of PGs in the circular muscle of the pylorus, PGE1 and PGE2 consistently reduced membrane resistance at any given membrane potential level when compared with that in Krebs solution. In other regions of the stomach, PGE1 and PGE2 depolarized the membrane, and reduced the membrane resistance at any given membrane potential level. The differences of PG action on the various regions of stomach were compared with those observed in the other visceral smooth muscles.View full abstractDownload PDF (1230K)
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