摘要：Dental plaque extracts and culture supernatants from ten strains of dental plaque bacteria were assayed for smooth muscle contracting activity which is indicative of inflammatory capability. Three types of smooth muscle contracting substances were detected. Firstly, a substance active on guinea-pig ileum, antagonised by mepyramine, and produced in higher levels when cultures were grown with histidine. Secondly, a substance active on the rat fundic strip preparation, antagonised by N,N-dimethyltryptamine, and produced in higher levels when cultures were grown with tryptophan. These spasmogens were probably histamine and tryptamine respectively. The histamine-like and tryptamine-like activity measured in a dental plaque extract gave levels equivalent to 100 and 84 nmole of respective amine per g wet weight of plaque. A third group of spasmogens active on the rat fundic strip preparation were detected in culture supernatants. This activity was probably caused by acetate, propionate, butyrate and other short chain fatty-acid salts which at sub-threshold concentrations would interact synergistically with histamine or tryptamine. The findings taken together suggest that in vivo, dental plaque microorganisms may be capable of producing both vasoactive amines and carboxylic acids which by acting singly or synergistically may cause or contribute to periodontal inflammation in the host.Keywords: Dental plaque; Histamine; Inflammatory compounds; Periodontal disease; Tryptamine; Short chain fatty acids.
