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Vasopressin potentiates corticotropin-releasing hormone-induced insulin release from mouse pancreatic β-cells

By Anne-Marie O'Carroll, Gillian M Howell, Emma M Roberts and Stephen J Lolait

Abstract

Arginine vasopressin (AVP) and corticotropin-releasing hormone (CRH) have both been implicated in modulating insulin secretion from pancreatic β-cells. In the present study, we investigated the insulin-secreting activities of AVP and CRH in wild-type and AVP VIb receptor knockout mice. Both neuropeptides stimulated insulin secretion from isolated mouse pancreatic islets. The response of islets to CRH was increased fourfold by concomitant incubation with a subthreshold dose of AVP that alone did not stimulate insulin secretion. Activation of the endogenously expressed M3 receptor by the cholinergic agonist carbachol also potentiated CRH-induced insulin secretion, indicating that the phenomenon may be pathway specific (i.e. Ca2+-phospholipase C) rather than agonist specific. The protein kinase C (PKC) inhibitors Ro-31-8425 and bisindolylmaleimide I attenuated the potentiating effect of AVP on CRH-stimulated insulin secretion and blocked AVP-stimulated insulin secretion. A possible interaction between the PKC and protein kinase A pathways was also investigated. The phorbol ester phorbol myristate acetate (PMA) stimulated insulin secretion, while the addition of both PMA and CRH enhanced insulin secretion over that measured with either PMA or CRH alone. Additionally, no AVP potentiation of CRH-stimulated insulin secretion was observed upon incubation in Ca2+-free Krebs–Ringer buffer. Taken together, the present study suggests a possible synergism between AVP and CRH to release insulin from pancreatic β-cells that relies at least in part on activation of the PKC signaling pathway and is dependent on extracellular Ca2+. This is the first example of a possible interplay between the AVP and CRH systems outside of the hypothalamic–pituitary–adrenal axis

Topics: Regular papers
Publisher: BioScientifica
OAI identifier: oai:pubmedcentral.nih.gov:2386661
Provided by: PubMed Central
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    1. (1997). Arginine vasopressin stimulates CRH and ACTH release by rat adrenal medulla, acting via the V1 receptor subtype and a protein kinase C dependent pathway.
    2. (2008). AVP potentiates CRH-induced insulin release 238
    3. (1984). Corticotropin releasing factor (CRF)-like immunoreactivity in the adrenal medulla.
    4. (1982). Corticotropin releasingactivityof the new CRF is potentiated several times by vasopressin.
    5. (2003). Crosstalk between camp and Ca 2C signalling in non-excitable cells.
    6. (2006). Direct regulation of insulin secretion by angiotensin II in human islets of Langerhans.
    7. (1987). Distinct mechanisms for two amplification systems of insulin release.
    8. (2005). Dopamine D2-like receptors are expressed in pancreatic beta cells and mediate insulin secretion.
    9. (1995). Effect of AVP and oxytocin on insulin release: involvement of V1b receptors.
    10. (2004). Effects of muscarinic receptor type 3 knockout on mouse islet secretory responses.
    11. (1983). Effects of synthetic ovine corticotropin-releasing factor, glucocorticoids, catecholamines, neurohypophysial peptides, and other substances on cultured corticotropic cells.
    12. (1983). Interaction of corticotropin-releasing factor and arginine vasopressin on adrenocorticotropin secretion in vivo.
    13. (1986). Involvement of protein kinase C in the regulation of adrenocortictropin release from rat anterior pituitary cells.
    14. (2004). Mechanisms of arginine-vasopressin-induced Ca 2C oscillations in b-cells (HIT-T15): a role for oscillating protein kinase C.
    15. (1990). Mechanisms of the stimulation of insulin release by arginine–vasopressin in normal mouse islets.
    16. (1995). Molecular cloning and characterization of the rat V1b vasopressin receptor: evidence for its expression in extra-pituitary tissues.
    17. (1999). Molecular mechanisms and regulation of insulin exocytosis as a paradigm of endocrine secretion.
    18. (2006). Neuropeptides and the regulation of islet function.
    19. (1988). Oxyocin and vasopressin are present in human and rat pancreas.American
    20. (2003). Pancreatic vasopressin V1b receptors: characterization in In-R1-G9 cells and localization in human pancreas.
    21. (1971). Potentiation by vasopressin of corticotropin release induced by corticotropin-releasing factor.
    22. (2008). Received in final form 15
    23. (2002). Recent advances in the Okamoto Model. The CD38-cyclic ADP-ribose signal system and the regenerating gene protein (Reg)-reg receptor system in b-cells.
    24. (2004). Reproductive functions of corticotropin-releasing hormone. Research and potential clinical utility of antalarmins (CRH receptor type 1 antagonists).
    25. (2005). The apj receptor is expressed in pancreatic islets and its ligand, apelin, inhibits insulin secretion in mice.
    26. (2006). The molecular mechanisms underlying the regulation of the biological activity of corticotropinreleasing hormone receptors: implications for physiology and pathophysiology.
    27. (1994). The role of protein kinase-C in signal transduction through vasopressin and acetylcholine in pancreatic B-cells from normal mouse.
    28. (2000). Triggering and amplifying pathways of regulation of insulin secretion by glucose.
    29. (2003). Urocortin III is expressed in pancreatic beta-cells and stimulates insulin and glucagon secretion. Endocrinology 144 3216–3224. LiC,ChenP,VaughanJ,LeeK-F&ValeW2006Urocortin3regulatesglucosestimulated insulin secretion and energy homeostasis.
    30. (2004). Vasopressin stimulates insulin release from islet cells through V1b receptors: a combined pharmacological/knockout approach.
    31. (2002). Vasopressin V1b receptor knockout reduces aggressive behaviour in male mice.

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