Effect of dopamine on glucose levels in hemolymph of Cyrtograpsus angulatus.

LOPEZ MAÑANES, A.A.

Rosario, Argentina

Congreso; XXIII Annual Meeting Rosario Biology Society; 2004

Sociedad de Biología de Rosario

Nota: El año de la reunión fue 2003. El sistema no me permitió poner la fecha correcta. In decapod crustaceans, biogenic amines (i.e dopamine) appeared to be involved in the regulation of several physiological processes (i.e osmoionoregulation and carbohydrates metabolism). Our previous work has shown a differential effect of dopamine (Dopa) and Na+,K+-ATPase and alkaline phosphatase activities in muscle of C. angulatus suggesting a role for Dopa in the regulation of mechanisms of adjustments upon hypo-osmotic stress. The aim of this work was to study the effect of Dopa on glucose levels in hemolymph and on release of glucose from hepatopancreas of C. angulatus upon hypo-osmotic stress. Adult male crabs were acclimated for at least for 30 days at 10 ‰ salinity. "In vivo" experiments: Crabs were injected with saline (control) or saline + 10-4 M Dopa. "In vitro" experiments: Sections of hepatopancreas (100 mg) were incubated with 10-4 M Dopa (control: saline solution). Glucose release was determined at different times (t min).Three independent experiments were carried out. T-test and ANOVA RM were used as statistical analysis (p<0.05). 10-4 M Dopa increased "in vivo" glucose level in hemolymph at 30 min (mg/100 ml hemolymph) (control:5.5±.78; Dopa:15.7±1.9) (p<0.01) and induced at 60 min the release of glucose from hepatopancreas(mg/gtissue)(Control:to=0.86±0.17;t15=1.3±0.34; t30=1.69±0.21;t60=1.73±0.27;Dopa;t15=1.67±0.13;t30=1.41± 0.14; t605.5±0.68). The results show that dopamine exhibited an hyperglicemic effect in C. angulatus upon hypo-osmotic stress and that part of this effect would involve its direct action on hepatopancreas, suggesting the role of dopamine in glucose homeostasis in hyperegulating conditions.