THE PREPARATION OF TROPHOCYTES FROM DISAGGREGATED FAT-BODY OF THE COCKROACH (PERIPLANETA-AMERICANA)

A method has been developed for disaggregating the fat body of the adu lt American cockroach, Periplaneta americana, using collagenase. The y ield of cells is sensitive to the osmolarity of the dispersing medium and to the age of the cockroaches from which the fat bodies are taken, Trophocytes uncontaminated with other cells were obtained by taking a dvantage of the low density of these cells which causes them to float to the top of the dispersion medium. In contrast, the mycetocytes and urocytes being denser than the medium sink to the bottom. The trophocy tes retain the ability to respond to the synthetic hyperglycaemic horm ones, CCI and CCII, as shown by the activation of phosphorylase and th e stimulation of trehalose efflux. The trophocytes incorporated leucin e into protein secreted by the cells in a time dependent manner.