Ca-ATPase localization and inhibition in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea)

Ca-ATPase activity was localized at the ultrastructural level in the gorgonian Leptogorgia virgulata (Lamarck). Weak enzyme activity was detected on the inner plasma membranes of the microvilli and the basal plasma membranes of the outer epithelium. Stronger activity was found in the membranes of the microvilli and lateral plasma membranes of the polyp epithelium. The basal portion of the polyp epithelium showed heavy activity. Weak activity was detected in the membranes of scleroblast electron-dense bodies, and scleroblast plasma membranes, whereas moderate enzyme activity was demonstrated on the inner membranes of the microvilli of the desmocytes. Intense activity was found within the microvilli of the desmocytes which are deeply embedded in the cortex of the axis. A 45Ca-uptake study with and without the Ca-ATPase inhibitor quercetin substantiated the findings. These results indicate that the axis is actively involved in the calcification process.