Induced inflammatory process in the sea urchin Lytechinus variegatus

In vitro and in vivo studies confirmed endocytic activity of free phagocytic amebocytes in Lytechinus variegatus. Amebocytes in the perivisceral coelom were labeled with injected ferritin, and ferritin-labeled amebocytes were found in the peristomial connective tissue only one hour after injection of India ink or yeast into this tissue. The presence of ferritin inside the amebocytes indicates that these cells migrated from the perivisceral coelom to the peristomial connective tissue. After 24 hours, particles of India ink or yeast were observed inside the ferritin-labeled amebocytes, indicating the amebocytes' ability to respond to an inflammatory stimulus. These were the only inflammatory cells found in L. variegatus, using the above mentioned stimuli and time spans.