CHANGES IN POLYAMINE LEVELS IN RESPONSE TO ACCLIMATION SALINITY IN GILLS OF THE BLUE-CRAB CALLINECTES-SAPIDUS RATHBUN

The concentration of putrescine in gills 3, 4, 6 and 7 was approximate ly two-fold higher in gills acclimated to 35 ppt salinity than in thos e acclimated to 10 ppt salinity for 28 days (c, 90 nmol/g wet weight v s 40 nmol/g wet weight, respectively). Spermine concentration was sign ificantly higher in gills 6 and 7 than in gills 3 and 4 at 10 ppt sali nity, and also was significantly higher than in gills 6 and 7 of crabs acclimated to 35 ppt salinity, Putrescine concentrations varied inver sely and spermine concentrations varied directly with specific activit y of Na+, K+-ATPase in all gills. On the basis of these data and other recent reports, we suggest that polyamines are involved in the regula tion of osmotic and ionic homeostasis by interacting directly with the Na+, K+-ATPase enzyme.