Phrenic nerve - diaphragm

Varagic, V. M. and Zugic, M., Interactions of xanthine derivatives, catecholamines, and glucose-6-phosphate on the isolated phrenic nerve diaphragm preparation of the rat, Pharmacology, 5, 275, 1971. 

Skeletal muscle Phrenic nerve/diaphragm Neuromuscular blockade... 

Brodin P, Rped A. (1984). Effects of eugenol on rat phrenic nerve and phrenic nerve-diaphragm preparations. Arch Oral Biol. 29(8) 611-15. 

Gallagher, J. and Shinnick, G.P., Effect of Gymnodium breve toxin in the rat phrenic nerve diaphragm preparation, Br. J. Pharmac., 69, 367, 1980. 

Holmes and Robins reported that 2-PAM I overcame neuromuscular blockade induced by DFP, TEPP, or sarin, but this could be demonstrated with the Isolated phrenic nerve-diaphragm preparation from the rat only after washing away excess OP compound. Intravenous injection of 2-PAM I overcame slowly neuromuscular blockade induced by OP compounds. The oxime, they found, also had a direct toxic action on muscle, reducing the ability of muscle to shorten and decreasing the ability of muscle fibers to conduct impulses. The same investigators reported that V (intraperltoneally at 150 mg/kg) had little, if any, effect on a sarin-induced blockade of neuromuscular transmission. 

Table 5.7. EFFECT OF VITAMIN E ON RESPONSES OF RAT PHRENIC NERVE-DIAPHRAGM PREPARATION IN HYPOXIA...

Neuromuscular Phrenic nerve-diaphragm Ginsborg and Hirst 1972... 

Phrenic nerve-diaphragm preparation (frog xanthine-sensitive receptor) ... 

Pumiliotoxin B has both cardiotonic and myotonic activity in isolated atrial or rat phrenic nerve diaphragm preparations (97). The cardiotonic activity is markedly dependent on the structure of the pumiliotoxin (95). Subsequent studies on the activity of pumiliotoxin B in neuromuscular preparations were interpreted as due to an apparent facilitation of calcium translocation from internal storage sites (99 see review in Ref. 5). Inhibitory effects on the calcium-dependent ATPase of sarcoplasmic reticulum were shown to be due not to pumiliotoxin B, but to phenolic impurities, namely, fcis(2-hydroxy-3-terf-butyl-5-methylphenyl)methane, 3,5-di-/ert-butyl-4-hydroxytoluene (BHT), and nonylphenols (100). 

Lin, R.H., Fu, W.M., Lin-Shiau, S.Y. (1988). Presynaptic action of uranyl nitrate on the phrenic nerve-diaphragm preparation of the mouse. Neuropharmacology 27 857-63. 

The effects of anti-ganglioside antibody-mediated injury on motor nerve terminals have been extensively examined by in vitro phrenic nerve-diaphragm preparations. Current... 

Heffron, P. F., Hobbinger, F. (1979). Relationship between inhibition of acetylcholinesterase and response of the rat phrenic nerve-diaphragm preparation to indirect stimulation at higher frequencies. British Journal of Pharmacology, 66, 323—329. 

This MLA fraction was also tested for insecticidal activity against Spodoptera eridania and Musea domeStica, and was toxic to both. A previous study by Aiyar et al. had shown that MLA was the alkaloid responsible for causing the death of cattle feeding on Delphinium brownii in Western Canada (10) They also demonstrated that MLA had a neuromuscular blocking action in a rat phrenic nerve-diaphragm preparation, which was probably due to an effect on the nicotinic cholinergic receptor. The EC50 for this effect was 2.3 pM. 

The toxicity of starfishes may be derived from the saponins. The biological activities of these compounds were reported, including haemolytic properties, and antitumour [104] and antibacterial activities [105]. Inhibition activities for influenza virus multiplication, and anti-inflammatory activity towards contraction of the rat phrenic nerve diaphragm preparation, were also reported [106]. Saponins are chemical defence agents in starfishes, and they also induce escape reactions in bivalve molluscs [107]. It is of interest to note that the sperm agglutination substance in the egg jelly of starfish is similar to asterosaponin A [108]. 

During stimulation of cholinergic nerves (e.g., phrenic nerve diaphragm preparation) there is a 2-5 fold increase in released ACh (Krnjevic and Mitchell, 1961 Mitchell and Silver, 1963 Schmidt, Szilagyi, Alkon and Green, 1970, Szerb, 1971). 

Schmidt, D. E., Szilagyi, P. I. A., Alkon, D. L. and Green, J. P. (1970) A method for measuring nanogram quantities of acetylcholine by pyrolysis-gas chromatography The demonstration of acetylcholine in effluents from the rat phrenic nerve-diaphragm preparation. J. Pharmacol, exp. Ther., 174, 337-345. 

Barstad, J.A.B., Cholinesterase inhibition and the effect of anticholinesterases on indirectly evoked single and tetanic muscle contractions in the phrenic nerve-diaphragm preparation from the rat, Arch. Int. Pharmacodyn., 128, 143, 1960. 

In 1969 Landau and Kwanbunbumpen carried out the electron-microscopic study as indicated by Eccles. Polarizing currents were passed through the rat phrenic nerve-diaphragm preparation for 3 min after which a 3 %... 

Lis Balchin et al. [69] studied the action of S. sclarea oil on the rat isolated phrenic nerve diaphragm preparations and compared with activity on field- stimulated guinea-pig ileum preparations. The oil produced a contracture and inhibition on the skeletal muscle of the bi-phasic response to nerve stimulation, whilst only a contracture, with or without a decrease in response to field stimulation, was produced in smooth muscle. 

Tetanic contractions (Wedensky inhibition) induced by repetitive nerve stimulation in phrenic nerve-diaphragm preparations of mice was faded by 0.5-2 ijlM neostigmine (Chang ei al., 1986). The fade was brought about by failure to elicit muscle action potentials, which was due to end-plate depolarization and a decrease in transmitter release. Both effects were attributed to ACh accumulation as a result of ChE inhibition. 

Mecr, C.. and Van der Meter, E. (1956). The mechanism of action of anticholine.stcrase. II. The effect of diisopropylfluorophos-phonate (DFP) on the isolated rat phrenic nerve diaphragm preparation. A. Irreversible effects. Acta Physiol Pharmacol 4, 454-471. 

Table 3. Potentiating En ects of P-EudesmoI-related Cyclohexylidene Derivatives (KTE-13, -32 and -33) on Suxamethonium (SuCh)-Induced Neuromuscular Block on Phrenic Nerve-diaphragm Muscle Preparations of Normal and Alloxan-diabetic mice...

Fig. (6 a). Influence of the position of the side-chains on the phenylene ring of bis(4-trimethylammoniobutyl)benzene (upper) and of the side-chain length of bis-trimethylammonium derivatives (lower) on neuromuscular blocking activity. The percentage inhibition of nerve-stimulated twitch response in mouse phrenic nerve-diaphragm muscle is plotted against the log concentration. The values represent means S.E.M. (n = 4-7). 

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