Nucleotide receptors in hepatic stellate cells of the rat.
When hepatic stellate cells were stimulated by UTP, ATP, or ADP, cellular levels of inositol phosphates significantly increased (UTP > ATP > ADP > 5'-O-(3-thiotriphosphate). Thirty min after incubation with 100 microM of UTP, ATP, or ADP, levels of inositol monophosphate increased to 1318 +/- 116, 616 +/- 87 and 591 +/- 234% of control levels, respectively, with concomitant increase in the production of inositol trisphosphate and bisphosphate. These nucleotides transiently increased the [Ca2+]i of fura-2-loaded stellate cells. Moreover, UTP, ATP, ADP and adenosine 5'-O-(3-thiotriphosphate) were able to induce contraction of stellate cells as detected using the silicone-rubber membrane method. These results suggested that hepatic stellate cells have nucleotide receptors which react predominantly with extracellular UTP and ATP and trigger the receptor-mediated contraction of the cells.
Department of Surgery, Osaka City University Medical School, Japan.
S
S
Takemura
N
N
Kawada
K
K
Hirohashi
H
H
Kinoshita
M
M
Inoue
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D007295:Inositol Phosphates / Q000378:metabolism; D008099:Liver / Q000098:blood supply / Q000166:cytology / Q000502:physiology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000502:physiology*; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D012265:Ribonucleotides / Q000494:pharmacology*
D007295:Inositol Phosphates; D011956:Receptors, Cell Surface; D018048:Receptors, Purinergic P2; D012265:Ribonucleotides; C074644:uridine triphosphate receptors; D002118:Calcium