Effects of Different Calcium Concentration on the Retinular Cell in the Shrimp Macrobrachium nipponense

Abstract: In order to further study the effects of Crustacea抯 retinular cells under different calcium concentration， the dark adapted retinular cells of the photoreceptors in the shrimp (Macrobrachium nipponense)， that were incubated in physiological saline and in presence of different calcium concentrations， were studied with electron microscopy. The results showed that in presence of 50 mmol/L calcium， the fine structure of the retinular cells had the characters of the cells in light adaptation. The diameter of the rhabdoms reduced extremely. The microvillus that composed the rhabdoms arranged in disorder. Cells contained more multivesicular bodies and more lamellar bodies. The pigment granules were more and located in the whole cells. The retinular cells that were incubated in physiological saline (10 mmol/L) or in low calcium saline (50 mmol/L EGTA and 2 mmol/L) had same fine structures that showed the characters in dark adaptation. The calcium concentrations out of cells effected not only on the fine structures of the retinular cells but also on the calcium deposited in the organelles. In higher calcium solution that deposited more calcium in the organelles. The number of the deposits of calcium antimonate that were found in the organelles such as perirhabdomal vacuole， mitchondria， multivesicular body and pigment granule were more in higher calcium solution than in low calcium solution. Our studies concluded that the calcium out of retinular cells influenced the calcium in retinular cells， and those influence the function of the retinular cells by effects on the fine structure of the cells.
    

CSTR: 32200.14.cjcb.2006.02.0023