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Ratios of Ions Required to Maintain the Heart Beat of the American Cockroach, Periplaneta Americana Linnaeus

1957; Oxford University Press; Volume: 50; Issue: 3 Linguagem: Inglês

10.1093/aesa/50.3.244

1938-2901

Daniel Ludwig, Sister Kathleen Marie Tracey, Mary-Louise Burns,

Insects and Parasite Interactions

A variety of saline solutions, having wide ranges of ionic concentrations and osmotic pressures, have been used for insect tissues. A review of this work is given by Barsa (1954). Several investigators have attempted to formulate satisfactory saline solutions for the American cockroach, Periplaneta americana. Pringle (1938) used a solution hypotonic to cockroach blood, with a Na/K ratio of 34, and a K/Ca ratio of 1.4. Yeager's (1939) solution is isotonic and the corresponding ion ratios are 5.2 and 2.7, respectively. The best solutions developed by Griffiths and Tauber (1943) are hypertonic with Na/K ratios which ranged from 26 to 53, and K/Ca ratios from 0.7 to 1.4. The fact that satisfactory results were obtained by each investigator shows a great tolerance of isolated tissues to the composition of the surrounding medium.