Frog Rectus Abdominis Research Articles

Some NSN-tris quaternary neuromuscular blocking agents.

Abstract The tris-quaternary compounds 7-ethyl-7-thioniatridecylenebis(triethylammonium) triiodide (Dihexasulphonium triethiodide; DHSE), 6-ethyl-6-thioniaundecylenebis(triethylammonium) triiodide (Dipentasulphonium triethiodide; DPSE), and 7-methyl-7-thioniatridecylenebis(trimethylammonium) triiodide (Dihexasulphonium trimethiodide; DHSM) have been synthesised. DPSE and DHSE have been shown to be neuromuscular blocking agents, which act by a mechanism resembling that of tubocurarine and gallamine rather than decamethonium. DPSE and DHSE are about equipotent with tubocurarine on the cat gastrocnemius muscle, but less potent on the frog rectus abdominis muscle and rat diaphragm, and the head drop doses are higher. Neuromuscular block can be reversed by neostigmine, eserine, and edrophonium. DHSE and DPSE do not cause ganglion blockade or histamine release, do not increase heart rate and are less potent than tubocurarine in causing respiratory paralysis.

PHARMACOLOGICAL ACTIONS OF PURE MUSCARINE CHLORIDE

The action of chromatographically pure crystalline muscarine chloride, prepared from Amanita muscaria, has been compared with acetylcholine chloride (ACh) on a number of different organs from a variety of species. Muscarine caused spasm in vivo and in vitro of muscles of the gut, uterus, urinary bladder, and bronchus. It also caused contraction of the horse ureter and carotid artery chain in vitro and slowed the isolated auricles of the guinea-pig and rabbit, and the frog heart.Muscarine caused a drop in blood pressure, although in vitro it produced either constriction or dilatation of the blood vessels of the rabbit ear.All these actions resembled those of acetylcholine, though muscarine was usually more potent. Muscarine effects were readily prevented by atropine sulphate. It had a slight action on the frog rectus abdominis muscle, causing a contracture at high concentrations. Muscarine was destroyed neither by pepsin nor by boiling at any pH. It was inactive by mouth in a monkey in a quantity many times that which would cause poisoning by ingestion of Amanita muscaria in the human being. Muscarine neither inhibited nor was hydrolysed by either true- or pseudo-cholinesterase. Muscarine chloride did not cause paralysis of the neuromuscular junctions of the rat diaphragm or of the cat gastrocnemius.

Chemicopharmacological studies on antispasmodic action. VII. Antagonism to acetylcholine tested with rectus abdominis of frog.

Chemicopharmacological studies on antispasmodic action. VII. Antagonism to acetylcholine tested with rectus abdominis of frog.

A modification of receptor theory.

A modification of receptor theory.

Biological reactions of fluoroacetylcholine

Fluoroacetylcholine chloride has been synthesized and crystallized. It is hydrolyzed by both brain and serum cholinesterase. It is much less active than acetylcholine in inhibiting the beat of the frog heart or stimulating the contraction of frog rectus abdominus muscle.

Action of neostigmine, DFP and CT 3318 on the sensitivity of the frog rectus abdominis muscle to the acetic, propionic and butyric esters of choline

The potentiating effects of Neostigmine, D.F.P. and 3318 CT (a selective “true” cholinesterase inhibitor) on acetylcholine (ACh), propionylcholine (PrCh), butyrylcholine (BuCh) and amyltrimethylammonium (AmT), have been studied using the frog's rectus abdominis. Neostigmine increases the actions of the three esters much more than that of AmT. Low concentrations of D.F.P. potentiate maximally BuCh but have practically no effect on ACh, PrCh, and AmT. 3318 CT potentiates AcCh and PrCh but inhibits BuCh and AmT. These results indicate the specificity of the hydrolysis of pharmacologically active doses of BuCh, on the one hand, of AcCh and PrCh, on the other hand, by different enzymes or the frog's rectus. Results obtained with high concentrations of D.F.P. and with association of the different anticholinesterases indicate that a maximal or nearly maximal potentiation of one of these esters is already obtained with the specific inhibitor concerned; the supplementary inhibition of the non-specific enzymes thus appears to have no or only a poor effect.

A STUDY OF THE AUTONOMIC MANIFESTATIONS SEEN IN ACUTE ALDRIN AND DIELDRIN POISONING

The peripheral parasympathomimetic action of aldrin was investigated in vagotomized and adrenalectomized cats under chloralose and urethane anesthesia. Under these experimental conditions aldrin caused slowing of the heart, potentiated the effects of electrical stimulation of the vagus nerve, and augmented the secretory effect of the chorda tympani on the decentralized submaxillary salivary gland. Blood withdrawn five minutes after intravenous injections of aldrin into cats showed a reduced rate of destruction of added acetylcholine when tested on the frog's rectus abdominis muscle. In spite of a marked central action, dieldrin exerted none of these peripheral effects.

第4級鹽基の蛙腹直筋に對するクラレ樣作用並にワゴスチグミンの拮抗に就て

The quaternary bases examined were magnocurarine, laurifoline chloride and dauricine dimethiodide, isolated from Magnolia obovata, Cocculus laurifolius DC. and Menisperumum dauricum DC. respectively, which were tested for the curare-like activities on the frog's rectus abdominis with referenes in evaluation to ACh-, C10- as well as KCl doseresponse curves. Vagostigmin (prostigmine methylsulfate) was used as the antagonistic agent to these alkaloids, and the relation between these alkaloids and the ChE-activity of rabbits was studied in vitro where ChE activity was determined by titration after Hall and Lucas's method. Result : Curare-like action was proved in magnocurarine and laurifoline which was about one-tenth to one-twentieth as active as tubocurarine and vagostigmin was found also a potent antagonist to both alkaloids. This mode of action of vagostigmin is mainly based on its inhibitory effect on the ChE-activity and partially on its competitive ability to the receptor of neuromuscular junction. Dauricine was almost the same as active as tubocurarine, while the mode of curarelike action was not the same, unlike the above-mentionedmagnocurarine and laurifoline ; thereby vagostigmin antagonized imperfectively the action of dauricine, probably because dauricine had itself the ChE inhibitory action and so depressed the same action of vagostigmin. C10 had the ACh-like action on the frog's rectus abdominis, -under the effect of which the stimulant effect of ACh on the neuromuscular junction of the same muscle was not abolished, even if after ACh had been washed out from the preparation. This result indicated that C10 might induce the cumulation of ACh effect on the striated muscle preparation.

A STUDY OF THE AUTONOMIC MANIFESTATIONS SEEN IN ACUTE ALDRIN AND DIELDRIN POISONING

The peripheral parasympathomimetic action of aldrin was investigated in vagotomized and adrenalectomized cats under chloralose and urethane anesthesia. Under these experimental conditions aldrin caused slowing of the heart, potentiated the effects of electrical stimulation of the vagus nerve, and augmented the secretory effect of the chorda tympani on the decentralized submaxillary salivary gland. Blood withdrawn five minutes after intravenous injections of aldrin into cats showed a reduced rate of destruction of added acetylcholine when tested on the frog's rectus abdominis muscle. In spite of a marked central action, dieldrin exerted none of these peripheral effects.

エチールアルコール習慣形成に關する實驗的研究

Cholinesterase was determined by the biological method, using isolated Rectus abdominis of frog, in acute alcohol intoxicated and alcohol habituated rabbits. The results were as follows : The cholinesterase activity of brain, liver and serum of the acute intoxicated rabbits, showed approximately the same levels, when compared with the normal. rabbits. On the other hand, cholinesterase activity of tissues were significantly depressed in the alcohol habituated. It is probable that there is a certain relation between the acquirement of alcohol habituation and the depression of cholinesterase activity.

Action of inhibitors at the myoneural junction.

1. A study is presented of the actions of certain inhibitors on the frog rectus abdominis muscle stimulated by acetylcholine. 2. A type of analysis has been developed which provides a reliable criterion for judging whether an inhibitor is competing with acetylcholine for receptors at the myoneural junction or whether acting by a different mechanism. 3. The "curares" are shown to act by competitive inhibition at the myoneural junction, confirming earlier work of others on the mode of action of curare. 4. Atropine acts as an inhibitor at the myoneural junction. The inhibition may be non-competitive or it may be complicated by an additional effect at some point other than the myoneural junction. 5. A possible mechanism for anomalous inhibitor effects is the action of a single compound at more than one locus in the Ach mechanism. Eserine exerts such a dual effect at the end-plate. 6. Some of the available electrical and chemical data have been correlated to make possible a partial explanation of the role of Ach in transmission at the myoneural junction.

Effects of choline, acetate and citrate on the activity of the choline acetylating system of mammalian brain.

Nachmansohn, Hestrin and Voripaieff1 have reported that a highly active preparation, capable of synthesizing acetylcholine from acetate and choline (with certain other additions), can be obtained from extracts of acetone-dried brain (rabbit) by fractional precipitation with ammonium sulphate. The active material is contained in the 16–36 per cent fraction (16–36 gm. to 100 c.c. volume ammonium sulphate) and requires calcium ions to be fully effective. Two means of identifying acetylcholine are used: (1) assay on the frog rectus abdominis muscle and (2) chemical determination by the method of Hestrin2. The aforementioned authors find, however, that bioassay may give values more than twice those obtained chemically, and that incubation without choline yields bio-active material (equivalent to 80–100 µgm. acetylcholine/ml. of incubate) which is not chemically identifiable as acetylcholine. The nature of the substance responsible is unknown. It is formed largely by the 25–36 per cent ammonium sulphate fraction ; and acetylcholine by the 16–25 per cent fraction.

體外培養組織に於けるAcetylcholinの分解に就て

Y. Nakazawa has previously reported that acetylcholine was decomposed by the tissues of the chick embryo cultured, in vitro. In order to study more precisely, the tissue-slices of heart and liver of the chick embryo were cultivated, in a medium in Carrel's battles. Acetylcholine (ACh) was added to and the amount of undecomposed ACh after 18, 24 or 48 hours from the beginning was estimated biologically using frog's rectus abdominis. Results : ACh was decomposed not only by the heart-and liver tissues but also by the culture me dium itself which was made from the extract of the chick-embryo. So these tissue-slices wese cultured in vitro only with Ringer's solution as their nutrient source. No decomposition of ACh was observed in the cultured tissues, the growth of which have been checked by addition of As2O3. The decomposition of ACh by the cultured tissues was suppressed by the simultaneous presence of caffeine, vagostigmine, procaine, and physostigmine. The degree of suppression of ACh decomposition by caffeine was a little stronger in the heart tissue culture than in the liver culture, but it was just the opposite in the case of vagostigmine as well as of procaine. ACh when added in large amount together with physostigmine to the medium was decomposed more by the heart tissue than by the liver, but in the case of a small amount of ACh the condition was reversed. From the results it is concluded that ACh is decomposed by cholinesterase (ChE) inherently contained in these tissue-slices, and that the liver of the chick-embryo contains more true ChE than the heart, but the latter is more rich in the pseudo-ChE contents than the former.

Active relaxation of unstriated muscle.

Ramsey and Street1, working on single muscle fibres, concluded that relaxation in skeletal muscle was active. Prof. A. V. Hill2 has conclusively shown that relaxation in skeletal muscle is passive. We stimulated the frog's rectus abdominis with potassium salts and acetylcholine and did not find any active relaxation. In unstriated muscle relaxation is active under some conditions and passive under others3–5. In unstriated muscle there would appear to be two cycles: in one, the energy for contraction is derived from chemical stores; in the other, the energy for contraction is derived from energy previously stored in the structure. Striated muscle appears to possess the former cycle only. This, we think, is the fundamental difference between the two kinds of muscle.

The effect of certain analgesic drugs on synaptic transmission as observed in the perfused superior cervical ganglion of the cat.

1. In the perfused superior cervical ganglion of the cat the administration of morphine does not affect the size of the contraction of the nictitating membrane produced by pre‐ganglionic stimulation, injection of acetylcholine or of KCI when the pre‐ganglionic fibres are normally functional, but after degenerative section of the cervical sympathetic nerve, morphine in large doses potentiates the contraction elicited by injections of acetylcholine and of KCI.2. Pethidine and amidone strongly depress the responses of the membrane to pre‐ganglionic stimulation and to injections of acetylcholine or KCI. Both drugs have a similar depressant action on responses to acetylcholine and KCI after denervation of the ganglia. In these actions, 1‐amidone is the most powerful and pethidine the least powerful, while dl‐amidone is intermediate between the other two substances.3. Of the three analgesics tested, none have the power to excite a response of the nictitating membrane when injected into the ganglion.4. The effects of morphine, amidone and pethidine on the responses of the frog rectus abdominis muscle to acetylcholine are analogous to their effects on the responses of the denervated superior cervical ganglion to acetylcholine.

The pituitary and responses of the frog's heart and rectus abdominis to acetylcholine

The pituitary and responses of the frog's heart and rectus abdominis to acetylcholine

Acetylcholin及ビ抗Cholinesterase劑ノ作用機轉補遺(其ノ2)

The writer cxperimented the relation between the concentration and the action of A. Ch. on the eserinised rectus abdominis of frog, and the action of A. Ch. and atropine on the same, when both are present. The results are as follows.1) The relation between the concentration of A. Ch. and the action produced can be expressed 'by the formula where x concentration of A. Ch., y action produced, expressed as percent to the maximal possible action, and K constant. This relation suggests that a reversible monomolecular reaction occurs between A. Ch. and receptors either in the cell or on its surface.2) This relation is not influenced by atropine.3) The relation between the molar concentration of A. Ch. and Atropine on the eserinised abdominal rectus muscle of the frog is as follows.This formula shows that 1.5 molecules of atropine combine each receptor.After all the writer's results are similary as Clark's results. That is to say, cholinesterase has no effect upon the shape of the concentration-action curve.

PHARMACOLOGICAL ACTIONS OF QUATERNARY AMMONIUM SALTS

1. The author measured the actions of various quaternary ammonium salts on a series of isolated tissues, namely: leech muscle, frog's rectus abdominis, frog's auricle, and rat's gut.2. The following series of compounds were tested:—(1) Me3N.Me, Me3N.Et . . . Me3N.Oct, Me3N.Cet.(2) Me4N to Bu4N.(3) Me4N, Me3.EtN, Me2.Et2N, Me.Et3N, Et4N.(4) Me3N.Phen, Me3N.Benz, Me3N(CH2)2Phen.3. The tissues studied fell into three groups as regards their responses to the Me3N.R series:Group A. Leech muscle, which resembled in its response the motor‐nerve endings.Group B. The rectus abdominis.Group C. The frog's auricle and the rat's gut.In Group A all the compounds produced actions similar in kind but of varying intensity.In Group C a reversal of action occurred. An increase of R in the Me3N.R series caused increased activity up to Me3N.Am, but further increase abolished the action, and the higher compounds then inhibited the action of the lower members of the series.The responses of the rectus abdominis were intermediate in character between Groups A and C, but more nearly resembled those of Group C.4. The responses to the series Me4N, Et4N, Br4N, and But4N showed a similar grouping, but the similarity between the leech response and the curariform action was less complete.5. The series Me4N, Me3EtN, Me2Et2N, etc., showed more complex responses.6. The compound Me3N.CHPhen resembled in its actions Me3BuN and not Me3OctN. Hence the effect of introducing a phenyl group resembled that of the addition of 3 carbon atoms in a straight chain rather than that of the addition of 6 carbon atoms.It is with pleasure that I put in record my indebtedness to Prof. A. J. Clark for his kind hospitality, and for his constant help and advice. The expenses of this research were in part defrayed by the Moray Fund, for which help I express my thanks.

STUDIES ON PHOSPHORYLCHOLINE

1. Phosphorylcholine has been synthesised from choline chloride and phosphorus pentoxide and isolated as the double salt OCH2.CH2.N(CH3)3+ 2AgNO3.AgO—P—O‐O2. Phosphorylcholine, unlike most of the choline esters, is very stable towards alkaline and acid hydrolytic agents; this stability is attributed to the betaine structure of the compound.3. Phosphorylcholine is hydrolysed by kidney, bone, and serum phosphatase.4. The physiological properties of phosphorylcholine have been tested in the following ways: On the frog's heart, leech muscle, virgin guinea‐pig's uterus, cat's blood‐pressure and superior cervical ganglion, intestinal muscle of the rabbit, frog's rectus abdominus. In all cases its physiological activity was very slight, many thousand times less than the acetylcholine effect and sometimes qualitatively different from it. The physiological inertness of phosphorylcholine is again in accordance with its betaine structure.We wish to express our gratitude to Professor Sir F. G. Hopkins and Professor H. W. Florey for hospitality and interest.