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 adult American cockroach, Periplaneta americana, using collagenase. The yield 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 advantage 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 trophocytes retain the ability to respond to the synthetic hyperglycaemic hormones, CCI and CCII, as shown by the activation of phosphorylase and the stimulation of trehalose efflux. The trophocytes incorporated leucine into protein secreted by the cells in a time dependent manner.