Taurine release associated to volume regulation in rabbit lymphocytes.
Rabbit lymphocytes exposed to hyposmotic media first swell and then recover their initial volume within 6 min. During volume recovery, free amino acids (FAA) decrease from 451.1 to 208 nmoles/mg protein. Taurine was the dominating FAA, accounting for 70% of the FAA pool. The time course of 3H-taurine release induced by hyposmolarity followed that of volume recovery. Efflux of 3H-taurine in an 8 min period was 17.8% (of total labeled taurine accumulated during loading) in an isosmotic medium. Reducing osmolarity to 0.87, 0.75, 0.62, and 0.5 increased this release to 24.8%, 38.1%, 56.4% and 70.9%, respectively. The volume-sensitive release of 3H-taurine was unaffected by omission of external Na+ or Ca++ and was reduced by 23% in the absence of Cl-. It was unaffected by agents disrupting the cytoskeleton or by tetraethylammonium, barium, quinidine, and gadolinium, but was 26% reduced by DIDS. Taurine release was inhibited at 4 degrees C, but was unchanged at 15 degrees C or 25 degrees C. An involvement of FAA, particularly taurine, in lymphocyte volume regulation is suggested.
Jesuś García
J
J
Institute of Cell Physiology, National A. University of Mexico, México D.F.
Sánchez Olea
R
R
Pasantes-Morales
H
H
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D003078:Colchicine / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D005665:Furosemide / Q000494:pharmacology; D007038:Hypotonic Solutions / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D011802:Quinidine / Q000494:pharmacology; D011817:Rabbits; D013654:Taurine / Q000378:metabolism*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
D000596:Amino Acids; D007038:Hypotonic Solutions; D007473:Ion Channels; D013757:Tetraethylammonium Compounds; D013654:Taurine; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D000001:Calcimycin; D003571:Cytochalasin B; D019789:Tetraethylammonium; D005665:Furosemide; D011802:Quinidine; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D003078:Colchicine