Expression and coupling of somatostatin receptors in rat adrenal (PC12) and pituitary (GC) cell lines

Traina, Giovanna; Lanneau, Christophe; Porokhov, B; Bagnoli, Paola; Epelbaum, Jacques

doi:10.1016/s0304-3940(98)00565-5

Cited by 5 publications

(14 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous findings have also demonstrated that SRIF inhibitory effects on [Ca 2+ ] i are mediated by the activation of sst 2 receptors that, together with sst 1 receptors, are expressed by GC cell membranes (Mounier et al 1995;Traina et al 1998;Petrucci et al 2000). This conclusion has been supported by experiments using a novel sst 2 receptor antagonist, CYN-154806, that abolishes the SRIF-or the octreotideinduced inhibition of [Ca 2+ ] i (Petrucci et al 2000).…”

Section: Antagonistic Properties Of Cyn-154806mentioning

confidence: 72%

“…Of the SRIF receptors expressed by GC cell membranes, evidence obtained with specific SRIF receptor agonists and CYN-154806 has shown that sst 2 but not sst 1 receptors are coupled to an inhibition of the cAMP-dependent pathway (Traina et al 1998;Petrucci et al 2000). This finding has been corroborated by the present results showing that SRIF or octreotide decrease cAMP levels in a concentration-dependent manner with EC 50 values that are in the range of the affinity values reported for sst 2 receptors (Raynor et al 1993).…”

Section: Involvement Of Camp-dependent Pathwaysmentioning

confidence: 99%

“…Coupling of SRIF receptors to the cAMP-dependent pathway has been extensively demonstrated in different experimental models (for reference see Patel 1999). In GC cells, sst 2 but not sst 1 receptors are coupled to an inhibition of the adenylyl cyclase and their activation partially reduces FRSK-stimulated cAMP levels (Traina et al 1998;Petrucci et al 2000). cAMP-dependent pathways only in part mediate the sst 2 receptor-induced inhibition of [Ca 2+ ] i since blockade of the cAMP-dependent protein kinase (PKA) does not abolish the SRIF-induced decrease of [Ca 2+ ] i (Petrucci et al 2000).…”

Section: Introductionmentioning

confidence: 98%

“…This process is inhibited by the application of octreotide, a long-lasting SRIF agonist (Mounier et al 1995) that displays high affinity for sst 2 receptors, although it also binds to sst 5 receptors (Raynor et al 1993;Siehler et al 1998;Siehler and Hoyer 1999). Previous results have demonstrated that the membranes of GC cells express distinct SRIF receptors and, in particular, sst 1 and sst 2 receptors (Mounier et al 1995;Traina et al 1998;Petrucci et al 2000).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Somatostatin (SRIF) modulates distinct signaling pathways in rat pituitary tumor cells; negative coupling of SRIF receptor subtypes 1 and 2 to arachidonic acid release

Cervia

Fiorini

Pavan

et al. 2002

Naunyn-Schmiedeberg's Archives of Pharmacology

Self Cite

View full text Add to dashboard Cite

The somatotropin release-inhibiting factor somatostatin-14 (SRIF) is known to activate distinct receptor subtypes (sst1-5). In rat pituitary tumor cells (GC cells), sst2 but not sst1 receptors mediate the SRIF-induced inhibition of intracellular concentration of Ca2+ ([Ca2+]i) and are negatively coupled to cAMP-dependent pathways. In the present study, transduction mechanisms coupling distinct SRIF receptors to their specific functional role were investigated with the use of both SRIF agonists with well-known affinity at individual SRIF receptors and the sst2 receptor antagonist L-Tyr(8) isomer of Cyanamid 154806 (CYN-154806). Our results demonstrate that sst1 and sst2 receptors are coupled to distinct signaling pathways in GC cells. In particular, sst2 receptors are negatively coupled to the cAMP-dependent pathway and this pathway is partially responsible for the sst2 receptor-mediated inhibition of [Ca2+]i. In addition, sst1 and sst2 receptors are both coupled to a decrease of arachidonic acid (AA) release with an efficacy similar to that of SRIF, suggesting that SRIF reduces AA release through either a partial activation of both receptors or the activation of one at a time. This finding is important given the well-accepted role for phospholipase A2 (PLA2) as a positive signaling component in transduction pathways of SRIF receptors. sst1 and sst2 receptor negative coupling to PLA2/AA pathways does not seem to be implicated in the SRIF-induced inhibition of [Ca2+]i. The possible role for the SRIF-mediated inhibition of AA release in GC cell function remains to be elucidated.

show abstract

Section: Antagonistic Properties Of Cyn-154806mentioning

confidence: 72%

Section: Involvement Of Camp-dependent Pathwaysmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Somatostatin (SRIF) modulates distinct signaling pathways in rat pituitary tumor cells; negative coupling of SRIF receptor subtypes 1 and 2 to arachidonic acid release

Cervia

Fiorini

Pavan

et al. 2002

Naunyn-Schmiedeberg's Archives of Pharmacology

Self Cite

View full text Add to dashboard Cite

show abstract

“…In addition, confocal immunofluorecence experiments have shown that sst 5 receptor is the predominant SRIF receptor subtype expressed in virtually all GH‐producing cells while sst 1 receptor is the least expressed subtype (Kumar et al ., 1997). In contrast, the membranes of tumour somatotrophs express mostly sst 1 and sst 2 receptor mRNAs (Mounier et al ., 1995; Traina et al ., 1998) and little is known on the effects of their functional activation.…”

Section: Introductionmentioning

confidence: 99%