Effects of injection of biogenic amines on expression of gill related ion transporter mRNA and alpha-subunit protein in Litopenaeus vannamei.

We used semi-quantitative reverse transcription and the polymerase chain reaction (RT-PCR) to identify and characterize the mRNA of Na(+)/K(+)-ATPase alpha-subunit and Vacuolar-type H/-ATPase (V-ATPase) beta-subunit prepared from gills of the white shrimp Litopenaeus vannamei. Western blot and immunocytochemistry analysis were employeed to investigate the effects of biogenic amines such as dopamine (DA) and 5-hydroxytryptamine (5-HT) injection on expression of protein abundance and immunostained sites. Our results show that the gill Na(+)/K(+)-ATPase of 5-HT treatments increased lag to those of DA treatments. However, the DA and 5-HT have no significant effects on the activity of V-ATPase. The biogenic amines could induce the synthesis of Na(+)/K(+)-ATPase alpha-subunit mRNA in the first 12 h. The degree of change in Na(+)/K(+)-ATPase alpha-subunit mRNA expression were different between DA and 5-HT treated groups which depend on the dose. The expression of V-ATPase beta-subunit mRNA was not markedly affected by the biogenic amines. Concomitant elevation of Na(+)/K(+)-ATPase activity, alpha-subunit mRNA as well as protein abundance in response to injected biogenic amines was also found in Na(+)/K(+)-ATPase immunostained sites within the gill epithelium.

The effect of different acclimation temperatures on the prophenoloxidase system and other defence parameters in Litopenaeus vannamei.

Water temperature changes (higher and lower than 24 degrees C) were shown to have a significant effect on dopamine (DA) concentration, haemocyte count and the proPO system in the white shrimp Litopenaeus vannamei. No significant difference in any of the parameters was observed in the control group. DA concentration in haemolymph in the experimental groups increased to a peak value at 0.5 days; meanwhile serine protease (SP) activity and proteinase inhibitor (PI) activity decreased. Total haemocyte count (THC), differential haemocyte count (DHC) and PO activity were lowest at 1 day. All defence parameters became stable after 1-3 days, while the total haemocyte and large granular cell count stabilized after 6 days. After these stabilized, there was no significant difference in DA concentration and PI activity between the control and experimental groups, as was the case for the THC, DHC, PO and SP activities of shrimp held at higher temperatures. However these latter four parameters in the lower temperature groups were distinctly lower than the control group. alpha(2)-Macroglobulin activity in the experimental groups increased to a peak value after 1 day compared with the control and then stabilized after 6 days when the activity levels in higher temperature groups were higher than the control, while the lower temperature groups had no significant difference from the control. It was therefore concluded that water temperature changes modulated the immune system of L. vannamei.