Enzymatic and transport characteristics of isolated snake renal brush-border membranes

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · American Journal of Physiology; (USA)

OSTI ID:7007760

Benyajati, S; Dantzler, W H ^[1]

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1. Univ. of Arizona, Tucson (USA)

Brush-border membranes (BBM) or proximal tubules were isolated from the kidney of the garter snake (Thamnophis sirtalis) by a procedure involving hypotonic lysis, Ca precipitation, and differential centrifugation. The isolated membranes were enriched 15-fold in brush-border enzyme activities (alkaline phosphatase, {gamma}-glutamyl transpeptidase) compared with whole kidney homogenates and were substantially free of other contaminating membranes. The yield of the BBM preparation was 40%. The BBM vesicular transport of several organic solutes was characterized by a rapid filtration technique at 25{degree}C. D-glucose, p-aminohippurate (PAH), and urate entered the same osmotically active space and binding was minimal. An uptake overshoot for 3-O-methyl-D-glucose by reptilian BBM was observed only in the presence of an inwardly directed NaCl gradient and was abolished by 0.1 mM phlorizin. Reptilian BBM exhibited Na-gradient-stimulated uptake of PAH (90 {mu}M) with an overshoot that was inhibited by other organic acids and by 4-acetamido-4{prime}-isothiocyanostilbene-2,2{prime}-disulfonic acid (SITS). In contrast, urate uptake appeared to be Na independent and not appreciably affected by other organic anions or SITS. The presence of specific transport systems for organic solutes in the isolated membrane preparation distinctly characterizes the BBM of reptilian kidney.

• OSTI ID: 7007760
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:1; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ANIMALS
AROMATICS
AZAARENES
BIOCHEMICAL REACTION KINETICS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
CONTRAST MEDIA
ENZYME INHIBITORS
ESTERS
GLUCOSE
HETEROCYCLIC COMPOUNDS
HEXOSES
HIPPURAN
HYDROGEN COMPOUNDS
KIDNEYS
KINETICS
LABELLED COMPOUNDS
MEMBRANE TRANSPORT
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PHYSIOLOGY
PURINES
REACTION KINETICS
REPTILES
SACCHARIDES
SNAKES
SULFONIC ACID ESTERS
TRITIUM COMPOUNDS
TUBULES
UPTAKE
URIC ACID
VERTEBRATES
XANTHINES