Vasopressin stimulates phosphoinositide hydrolysis in LLC-PK sub 1 cells

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

OSTI ID:6289942

Garg, L C; Kapturczak, E; Steiner, M; Phillips, M I ^[1]

---

1. Univ. of Florida College of Medicine, Gainesville (USA)

LLC-PK{sub 1} cells have been shown to possess vasopressin (VP) receptors (V{sub 2} type) that are coupled to adenyl cyclase to generate adenosine 3,5{prime}-cyclic monophosphate (cAMP). To determine whether VP also stimulates phosphoinositide (PI) hydrolysis to generate inositol phosphate (IP) and diacylglycerol (DAG) messenger system in LLC-PK{sub 1} cells, the authors measured the release of IP in LLC-PK{sub 1} cells in the absence and presence of various concentrations of VP. In addition, the authors also determined the effect of an increase in osmolality of the incubation medium on VP-stimulated PI hydrolysis in LLC-PK{sub 1} cells. The methods involved the incubation of LLC-PK{sub 1} cells with ({sup 3}H)inositol for its incorporation into membrane PI and the measurement of the release of ({sup 3}H)IP in the presence of LiCl which prevents dephosphorylation. The osmolality of the incubation media was increased from 300 to 600, 900, and 1,200 mosmol/kgH{sub 2}O by the addition of NaCl and urea. In an isosmotic incubation medium, VP (10{sup {minus}8} M) produced a 100% increase in PI hydrolysis in LLC-PK{sub 1} cells. The effect was much greater at higher concentrations of the hormone. The results suggest that in LLC-PK{sub 1} cells, VP stimulates PI hydrolysis probably through VP receptors that are coupled to phospholipase C. Furthermore, VP-stimulated PI messenger system in LLC-PK{sub 1} cells is influenced by osmolality of the extracellular fluid.

• OSTI ID: 6289942
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:4; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
BIOLOGICAL EFFECTS
CARBOHYDRATES
CELL CULTURES
CHEMICAL REACTIONS
DECOMPOSITION
HORMONES
HYDROGEN COMPOUNDS
HYDROLYSIS
INOSITOLS
LYSIS
MEMBRANE PROTEINS
MONOSACCHARIDES
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHOSPHORYLATION
PITUITARY HORMONES
PROTEINS
RECEPTORS
SACCHARIDES
SOLVOLYSIS
TRITIUM COMPOUNDS
VASOPRESSIN