title: D1-like dopamine receptors downregulate Na+-K+-ATPase activity and increase cAMP production in the posterior gills of the blue crab Callinectes sapidus.
abstract: Dopamine-mediated regulation of Na(+)-K(+)-ATPase activity in the posterior gills of some crustaceans has been reported to be involved in osmoregulation. The dopamine receptors of invertebrates are classified into three groups based on their structure and pharmacology: D1- and D2-like receptors and a distinct invertebrate receptor subtype (INDR). We tested the hypothesis that a D1-like receptor is expressed in the blue crab Callinectes sapidus and regulates Na(+)-K(+)-ATPase activity. RT-PCR, using degenerate primers, showed the presence of D1βR mRNA in the posterior gill. The blue crab posterior gills showed positive immunostaining for a dopamine D5 receptor (D5R or D1βR) antibody in the basolateral membrane and cytoplasm. Confocal microscopy showed colocalization of Na(+)-K(+)-ATPase and D1βR in the basolateral membrane. To determine the effect of D1-like receptor stimulation on Na(+)-K(+)-ATPase activity, intact crabs acclimated to low salinity for 6 days were given an intracardiac infusion of the D1-like receptor agonist fenoldopam, with or without the D1-like receptor antagonist SCH23390. Fenoldopam increased cAMP production twofold and decreased Na(+)-K(+)-ATPase activity by 50% in the posterior gills. This effect was blocked by coinfusion with SCH23390, which had no effect on Na(+)-K(+)-ATPase activity by itself. Fenoldopam minimally decreased D1βR protein expression (10%) but did not affect Na(+)-K(+)-ATPase α-subunit protein expression. This study shows the presence of functional D1βR in the posterior gills of euryhaline crabs chronically exposed to low salinity and highlights the evolutionarily conserved function of the dopamine receptors on sodium homeostasis.
authors: The Marine Science Institute, University of the Philippines, Diliman, Quezon City, Philippines; Department of Pediatrics, Georgetown University School of Medicine, Washington, District of Columbia;
authors: Francis B
authors: FB
authors: Arnaldo
authors: Department of Pediatrics, Georgetown University School of Medicine, Washington, District of Columbia; Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
authors: Van Anthony M
authors: VA
authors: Villar
authors: Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
authors: Prasad R
authors: PR
authors: Konkalmatt
authors: Department of Pediatrics, Georgetown University School of Medicine, Washington, District of Columbia;
authors: Shaun A
authors: SA
authors: Owens
authors: Department of Pediatrics, Georgetown University School of Medicine, Washington, District of Columbia; Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
authors: Laureano D
authors: LD
authors: Asico
authors: Department of Pediatrics, Georgetown University School of Medicine, Washington, District of Columbia; Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
authors: John E
authors: JE
authors: Jones
authors: Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
authors: Jian
authors: J
authors: Yang
authors: Department of Biology, The College of New Jersey, Ewing, New Jersey; and.
authors: Donald L
authors: DL
authors: Lovett
authors: Department of Pediatrics, Georgetown University School of Medicine, Washington, District of Columbia; Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland;
authors: Ines
authors: I
authors: Armando
authors: Department of Pediatrics, Georgetown University School of Medicine, Washington, District of Columbia; Division of Nephrology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland; Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland pjose@medicine.umaryland.edu.
authors: Pedro A
authors: PA
authors: Jose
authors: The Marine Science Institute, University of the Philippines, Diliman, Quezon City, Philippines;
authors: Gisela P
authors: GP
authors: Concepcion
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D003386:Brachyura / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D000242:Cyclic AMP / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D015536:Down-Regulation; D005880:Gills / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D064587:Osmoregulation; D012333:RNA, Messenger / Q000378:metabolism; D050641:Receptors, Dopamine D5 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D054712:Salinity; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D012333:RNA, Messenger; D050641:Receptors, Dopamine D5; D000242:Cyclic AMP; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Na+-K+-ATPase; blue crab; cAMP; dopamine receptor; posterior gills