Sulfate-chloride exchange by lobster hepatopancreas is regulated by pH-sensitive modifier sites

Conference · Fri Mar 15 00:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5173717

Cattey, M A; Ahearn, G A; Gerencser, G A ^[1]

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1. Univ. of Hawaii, Honolulu (United States) Univ. of Florida, Gainesville (United States)

{sup 35}SO{sub 4}{sup 2{minus}} uptake by Atlantic lobster (Homarus americanus) hepatopancreatic epithelial brush border membrane vesicles (BBMV) was stimulated by internal Cl{sup {minus}}, but not internal HCO{sub 3}{sup {minus}}, or external Na{sup +}. Sulfate-chloride exchange was stimulated by inside positive, and inhibited by inside negative, trans-membrane K diffusion potentials. {sup 35}SO{sub 4}{sup 2{minus}}-Cl{sup {minus}} exchange was strongly inhibited by 4,4{prime} diisothiocyanostilbene-2,2{prime}-disulfonic acid (DIDS), 4-acetamido-4{prime}-isotheocynaostilbene-2,2{prime}-disulfonic acid, (SITS), and thiosulfate. Chloride, bicarbonate, furosamide, and bumetanide slightly, yet significantly, cis-inhibited {sup 35}SO{sub 4}{sup 2{minus}}-Cl{sup {minus}} exchange. Altering bilateral pH from 8.0 to 5.4 stimulated {sup 35}SO{sub 4}{sup 2{minus}}-Cl{sup {minus}} exchange when vesicles were loaded with Cl{sup {minus}}, but reduced bilateral pH alone or the presence of pH gradients did not affect {sup 35}SO{sub 4}{sup 2{minus}} transport in the absence of internal Cl{sup {minus}}. {sup 36}Cl uptake into SO{sub 4}{sup 2{minus}}-loaded BBMV was stimulated by an internal negative membrane potential and inhibited when the interior was electrically positive. A model is proposed which suggests that SO{sub 4}{sup 2{minus}}-Cl{sup {minus}} exchange is regulated by internal and external pH-sensitive modifier sites on the anion antiporter and by coupling to the electrogenic 2 Na{sup +}/1 H{sup +} antiporter and by coupling to the electrogenic 2 Na{sup +}/1 H{sup +} antiporter on the same membrane.

• OSTI ID: 5173717
• Report Number(s): CONF-9104107-; CODEN: FAJOE
• Journal Information: FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 5:5; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991; ISSN 0892-6638
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CHLORIDES
METABOLISM
SULFATES
EPITHELIUM
ION EXCHANGE
LIVER
LOBSTERS
MATHEMATICAL MODELS
MEMBRANE TRANSPORT
PANCREAS
PH VALUE
SULFUR 35
TRACER TECHNIQUES
ANIMAL TISSUES
ANIMALS
AQUATIC ORGANISMS
ARTHROPODS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CHLORINE COMPOUNDS
CRUSTACEANS
DAYS LIVING RADIOISOTOPES
DECAPODS
DIGESTIVE SYSTEM
ENDOCRINE GLANDS
EVEN-ODD NUCLEI
GLANDS
HALIDES
HALOGEN COMPOUNDS
INVERTEBRATES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
NUCLEI
ORGANS
OXYGEN COMPOUNDS
RADIOISOTOPES
SULFUR COMPOUNDS
SULFUR ISOTOPES
TISSUES
560300* - Chemicals Metabolism & Toxicology