Sodium transport in the freshwater mussel, Carunculina texasensis (Lea).
Freshwater bivalves maintain a Na steady state in artificial pondwater: JiNa = 1.2 +/- 0.1 mumol/g dry tissue per h. Na uptake is Cl independent. The affinity (KS) of the Na transport system is 0.15-0.23 mmol Na/1. Sodium influx is coupled to H and/or NH4 exchange. Salt depletion stimulates JiNa 300% relative to nondepleted animals with no change in Ks. Injected ammonium ion stimulates JiNa. Sodium transport is inhibited 84% by 0.5 mM amiloride but is not affected by 4 mM NH4 or 1 mM furosemide in the bathing solution or injection of acetazolamide (0.26 mumol/ml blood).
D000086:Acetazolamide / Q000494:pharmacology; D000584:Amiloride / Q000494:pharmacology; D000641:Ammonia / Q000378:metabolism; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D049872:Bivalvia / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*
D002712:Chlorides; D000641:Ammonia; D000584:Amiloride; D006859:Hydrogen; D012964:Sodium; D000086:Acetazolamide; D011188:Potassium