Differential expression of prostanoid receptors in hepatocytes, Kupffer cells, sinusoidal endothelial cells and stellate cells of rat liver

Induction by interleukin 6 of Gs-coupled prostaglandin E2 receptors in rat hepatocytes mediating a prostaglandin E2-dependent inhibition of the hepatocyte’s acute phase response

“…4). In line with the latter finding, the mRNA of none of the G s -coupled prostanoid receptors was detectable in freshly isolated hepatocytes 20 (Fig. 1 and Fig.…”

“…43,44 In line with this lack of evidence for a functional significance of PGD 2 in liver, the DP-R mRNA was not detected at all in hepatocytes and in only insignificant levels in the three major nonparenchymal liver cell types. 20 The induction by IL-6 of the DP-R mRNA in hepatocytes ( Fig. 1 and Fig.…”

“…Hepatocytes were cultured as described for the determination of the prostanoid receptor mRNA levels and in addition (c) for 36 hours before adding 100 ng/mL IL-6; culture was continued for 8 hours in the presence or absence of 100 ng/mL pertussis toxin (PTX) until 44 hours. Afterwards the medium was removed and cells were washed three times with HEPES-buffered saline (20 NOTE. Primer names are the name of the receptor subtype followed by ''f '' ϭ forward (sense) or ''r'' ϭ reverse (antisense).…”

EP1‐ and FP‐mediated cross‐desensitization of the alpha (α) and beta (β) isoforms of the human thromboxane A2 receptor

“…Hence, it is apparent that primary physiologic roles have been ascribed to many of the prostanoids and their receptors and those primary functions have been largely corroborated by observations from receptor knockout studies in mice Sugimoto et al, 2000). However, the existence of overlapping ligand specificities and the co-existence of more than one prostanoid receptor type, subtype or isoform (Kiriyama et al, 1997;van der Vuurst et al, 1997;Fennekohl et al, 1999) within a given cell/tissue adds greatly to the diversity of other actions of a given prostanoid within a particular cell or tissue type and greatly increases the complexity of downstream signalling resulting from prostanoid receptor activation . For example, the kidney is a major site of PG/TX synthesis (Breyer, 1998); while Northern blot analysis has confirmed the abundant coexpression of contractile EP 1 , FP and TP receptors within the kidney (Sugimoto et al, 2000) and each of these receptors can mediate contraction of renal mesangial cells (Breyer, 1998), the relative roles of these individual prostanoids in renal function and the possibility of intermolecular cross-talk/counter-regulation of their responses remain to be investigated.…”

Effects of Forskolin on Kupffer Cell Production of Interleukin-10 and Tumor Necrosis Factor Alpha Differ from Those of Endogenous Adenylyl Cyclase Activators: Possible Role for Adenylyl Cyclase 9

“…Several membrane receptors (G-coupled receptors) activate stimulating G proteins leading to cAMP production. Examples of two such wellknown receptor families present on Kupffer cells are the adrenergic receptor family and the prostanoid receptor family (7,11). Recently, mice deficient in the cAMP-inducing adenosine 2A receptors and pituitary adenylyl cyclase-activating polypeptide receptors were shown to be highly susceptible to developing sepsis, and the liver was identified as the organ mainly affected (5,34).…”