Reference

Effects of 4-aminopyridine on the non-adrenergic inhibitory neurotransmission in the guinea pig duodenum

Effects of 4-aminopyridine on the non-adrenergic inhibitory neurotransmission in the guinea pig duodenum. Ohkawa, Hiromichi (Sch. Med., Yamaguchi Univ., Ube 755, Japan). Jpn. J. Physiol., 34(5), 893-905 (English) 1984. CODEN: JJPHAM. ISSN: 0021-521X. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) The effects of 4-aminopyridine (4-AP) [504-24-5] on the nonadrenergic inhibitory potential in the longitudinal and circular smooth muscle cells of the guinea-pig duodenum were investigated using intracellular microelectrodes. The membrane potential of both smooth muscles was decreased by 4-AP and the amplitude of the evoked inhibitory potentials was increased. In a low-Ca soln. (0.25 mM), the amplitude of the inhibitory potentials was reduced but the addnl. application of 4-AP increased the amplitude. In the 4-AP contg. low-Ca soln., the inhibitory potential was inhibited by verapamil and EGTA. The inhibitory effect of verapamil on the i.p. evoked in a low-Ca soln. was less in the presence of 4-AP than that in its absence. In a high-Ca soln. (5 mM), the amplitude of the inhibitory potential increased and the addnl. application of 4-AP enhanced the inhibitory potential further. The amplitude of the inhibitory potential elicited in high-K solns. was not changed by 4-AP. The inhibitory potential was not potentiated by 2-aminopyridine [504-29-0] or 2,5-diaminopyridine [4318-76-7]. Tetraethylammonium ions enhanced the amplitude of the inhibitory potential at low concn. but decreased it in high concn. In a few longitudinal smooth muscle cells, the evoked excitatory potential was obsd. Potentiation of the excitatory potential by 4-AP was completely blocked by atropine. Apparently, the release of the nonadrenergic inhibitory neurotransmitter is increased by 4-AP due to increase Ca influx in the nerve terminals. The release of the cholinergic excitatory neurotransmitter seems to be increased by 4-AP.

Hair dyeing

Hair dyeing. Ebara, Tetsuo; Imabayashi, Shunichi (Koei Chemical Co., Ltd., Japan). Japan. Kokai JP 52034082 15 Mar 1977 Showa, 5 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: D06P001-32. APPLICATION: JP 75-111504 12 Sep 1975. DOCUMENT TYPE: Patent CA Section: 62 (Essential Oils and Cosmetics) Prepns. for hair dyeing contain (1) 2,5-diaminopyridine [4318-76-7] and toluene-2,5-diamine [95-70-5] or their salts, (2) 2,6-diaminopyridine [141-86-6], m-phenylenediamine [108-45-2] or toluene-2,4-diamine [95-80-7] or their salts and (3) m-aminophenol [591-27-5] (or its salts) or resorcein [33869-21-5]. The prepns. also can be used for coloring other keratin substances. Thus, a hair dye consists of 2,5-diaminopyridine 2.8, toluene-2,5-diamine 3.6, 2,6-diaminopyridine 0.4, resorcein 2.8, polyoxyethylene nonylphenyl ether 27.2, polyoxyethylene lauryl ether 13.2 and, coconut oil fatty acid diethanolamide 4.0 g with 40.4 mL distd. H2O and 8.0 mL 28% NH3. The prepn. (70 mL) was mixed with 6% H2O2 (70 mL) prior to dyeing.