Detail of "12778-32-4"

Reference

The effect of b-bungarotoxin on acetylcholine and choline content of vertebrate tissues

The effect of b-bungarotoxin on acetylcholine and choline content of vertebrate tissues. Newton, Michael W.; Gundersen, Cameron B.; Jenden, Donald J. (Sch. Med., Univ. California, Los Angeles, CA 90024, USA). Toxicon, 21(6), 825-32 (English) 1983. CODEN: TOXIA6. ISSN: 0041-0101. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) The effects of intraventricularly or i.p. administered b-bungarotoxin (I) [12778-32-4] on the tissue content of acetylcholine [51-84-3] and choline [62-49-7] in 3 vertebrate species were studied. Intraventricular administration of I (1 mg, 105 min) in rats raised the acetylcholine content of the hippocampus and striatum, but not of the cortex. Choline was increased in all 3 brain regions. Injection of I i.p. (5 mg, 90 min) in rats increased the acetylcholine content of the diaphragm, tongue, temporalis muscle, and adrenal gland, but no significant change was seen in the heart atrium, eye, ileum, or superior cervical ganglion. Choline increased in the heart and adrenals. I increased acetylcholine in the mouse diaphragm to the same degree as in the rat. No alteration of sartorius muscle or tongue acetylcholine was obsd. after i.p. injection of I (5 mg) in the frog. Results from distribution studies using 125I-labeled I suggest that the obsd. differences in response to I cannot be accounted for by the distribution of I alone. The variable effects of I on tissue acetylcholine and choline content and the mechanism of action of I are discussed.

Presynaptic, facilitatory effects of the corticosteroid dexamethasone in rat diaphragm: modulation by beta-bungarotoxin

Presynaptic, facilitatory effects of the corticosteroid dexamethasone in rat diaphragm: modulation by beta-bungarotoxin. Veldsema-Currie, R. D.; Van Wilgenburg, H.; Labruyere, W. Th.; Langemeijer, M. W. E. (Pharmacol. Lab., Univ. Amsterdam, Amsterdam 1039 KP, Neth.). Brain Res., 294(2), 315-25 (English) 1984. CODEN: BRREAP. ISSN: 0006-8993. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 14 Low concns. of dexamethasone (Dex) [50-02-2] (up to 200 nM) increased the accumulation of choline (Ch) [62-49-7] and its incorporation into acetylcholine (ACh) [51-84-3] in the endplate-rich area (EPA) of stimulated and unstimulated rat diaphragms in the presence of 10 mM Ch. Tissue ACh was not altered, even after 140 min incubation. Thus, the specific radioactivity of ACh in the EPA was increased by Dex. The corticosteroid had no effects on acetylcholinesterase or choline acetyltransferase in diaphragm exts.There are some commonly used reagents with their cas registry numbers 50-02-2 and 62-49-7 in this article. In the same medium, the amplitudes of the miniature endplate potential (MEPP), miniature endplate current (MEPC), and endplate current (EPC) were also increased by Dex. Neither the quantal content of the EPCs nor the MEPP frequency nor the half-decay time of the MEPCs were altered. Therefore Dex (200 nM) increased both the resting and evoked output and turnover of ACh in rat diaphragm. b-Bungarotoxin (b-BuTx) [12778-32-4] antagonized the Dex-induced increase in Ch accumulation and its incorporation into ACh and abolished the increases in MEPC- and EPC-amplitudes, providing further argument for a presynaptic effect of Dex. In continuously-stimulated diaphragms, b-BuTx caused an accumulation of ACh which was much greater than in unstimulated tissue. This accumulation of ACh was less in the presence of Dex, provided that Dex was added before b-BuTx. The interaction of Dex and b-BuTx was discussed in terms of their possible presynaptic sites of action. .