Limits...
Insulin induces the release of vasodilator compounds from platelets by a nitric oxide-G kinase-VAMP-3-dependent pathway.

Randriamboavonjy V, Schrader J, Busse R, Fleming I - J. Exp. Med. (2004)

Bottom Line: Insulin failed to relax endothelium-intact rings of porcine coronary artery.Insulin induced the release of adenosine trisphosphate (ATP), adenosine, and serotonin from platelet-dense granules in a NO-dependent manner.The mechanism of dense granule secretion involves the G kinase-dependent association of syntaxin 2 with vesicle-associated membrane protein 3.

View Article: PubMed Central - PubMed

Affiliation: Institut für Kardiovaskuläre Physiologie, Klinikum der J.W.Goethe-Universität, D-60590 Frankfurt am Main, Germany.

ABSTRACT
Insulin-induced vasodilatation is sensitive to nitric oxide (NO) synthase (NOS) inhibitors. However, insulin is unable to relax isolated arteries or to activate endothelial NOS in endothelial cells. Since insulin can enhance platelet endothelial NOS activity, we determined whether insulin-induced vasodilatation can be attributed to a NO-dependent, platelet-mediated process. Insulin failed to relax endothelium-intact rings of porcine coronary artery. The supernatant from insulin-stimulated human platelets induced complete relaxation, which was prevented by preincubation of platelets with a NOS inhibitor, the soluble guanylyl cyclase inhibitor, NS 2028, or the G kinase inhibitor, KT 5823, and was abolished by an adenosine A2A receptor antagonist. Insulin induced the release of adenosine trisphosphate (ATP), adenosine, and serotonin from platelet-dense granules in a NO-dependent manner. This response was not detected using insulin-stimulated platelets from endothelial NOS-/- mice, although a NO donor elicited ATP release. Insulin-induced ATP release from human platelets correlated with the association of syntaxin 2 with the vesicle-associated membrane protein 3 but was not associated with the activation of alphaIIbbeta3 integrin. Thus, insulin elicits the release of vasoactive concentrations of ATP and adenosine from human platelets via a NO-G kinase-dependent signaling cascade. The mechanism of dense granule secretion involves the G kinase-dependent association of syntaxin 2 with vesicle-associated membrane protein 3.

Show MeSH

Related in: MedlinePlus

Pharmacological characterization of the pathway involved in the insulin-induced release of a platelet-derived relaxing factor. (a) Effect of the guanylyl cyclase inhibitor, NS 2028 (NS, 10 μmol/L, 30 min), and the G kinase inhibitors, KT 5823 (KT, 1 μmol/L, 30 min) and Rp-8CPT-cGMPs (Rp, 10 μmol/L, 30 min), on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets, i.e., inhibitors applied to the platelet donor and the detector artery ring compared with the effects observed when the inhibitors were applied only to the detector ring. (b) Statistical summary showing the effect of L-NA (300 μmol/L, 30 min), diclofenac (Dl, 10 μmol/L, 30 min), the phospholipase A2 inhibitor AACOCF3 (AA, 3 μmol/L, 30 min), and the adenylyl cyclase inhibitor 2′,3′-dideoxyadenosine (DDA, 100 μmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. (c) Summary showing the effect of the AMPK inhibitor iodotubercidin (Iodo, 1 μmol/L, 30 min) and the phosphatidylinositol 3-kinase inhibitor wortmannin (Wort, 40 nmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. The results shown represent the mean ± SEM of data obtained in five to seven independent experiments. **P < 0.01 and ***P < 0.001 versus the response obtained using the supernatant from unstimulated platelets (Sol).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2211801&req=5

fig2: Pharmacological characterization of the pathway involved in the insulin-induced release of a platelet-derived relaxing factor. (a) Effect of the guanylyl cyclase inhibitor, NS 2028 (NS, 10 μmol/L, 30 min), and the G kinase inhibitors, KT 5823 (KT, 1 μmol/L, 30 min) and Rp-8CPT-cGMPs (Rp, 10 μmol/L, 30 min), on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets, i.e., inhibitors applied to the platelet donor and the detector artery ring compared with the effects observed when the inhibitors were applied only to the detector ring. (b) Statistical summary showing the effect of L-NA (300 μmol/L, 30 min), diclofenac (Dl, 10 μmol/L, 30 min), the phospholipase A2 inhibitor AACOCF3 (AA, 3 μmol/L, 30 min), and the adenylyl cyclase inhibitor 2′,3′-dideoxyadenosine (DDA, 100 μmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. (c) Summary showing the effect of the AMPK inhibitor iodotubercidin (Iodo, 1 μmol/L, 30 min) and the phosphatidylinositol 3-kinase inhibitor wortmannin (Wort, 40 nmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. The results shown represent the mean ± SEM of data obtained in five to seven independent experiments. **P < 0.01 and ***P < 0.001 versus the response obtained using the supernatant from unstimulated platelets (Sol).

Mentions: When the soluble guanylyl cyclase inhibitor, NS2028 (10 μmol/L), or the G kinase inhibitors, KT 5823 (1 μmol/L) or Rp-8CPT-cGMPs (10 μmol/L), were present throughout the platelet stimulation and the organ chamber experiments, the relaxation of porcine coronary artery rings was significantly attenuated. However, when these compounds were present in the organ chamber but not present throughout the preparation of the platelet supernatant, no effect on the insulin-induced release of a platelet-derived relaxing factor was observed (Fig. 2 a).


Insulin induces the release of vasodilator compounds from platelets by a nitric oxide-G kinase-VAMP-3-dependent pathway.

Randriamboavonjy V, Schrader J, Busse R, Fleming I - J. Exp. Med. (2004)

Pharmacological characterization of the pathway involved in the insulin-induced release of a platelet-derived relaxing factor. (a) Effect of the guanylyl cyclase inhibitor, NS 2028 (NS, 10 μmol/L, 30 min), and the G kinase inhibitors, KT 5823 (KT, 1 μmol/L, 30 min) and Rp-8CPT-cGMPs (Rp, 10 μmol/L, 30 min), on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets, i.e., inhibitors applied to the platelet donor and the detector artery ring compared with the effects observed when the inhibitors were applied only to the detector ring. (b) Statistical summary showing the effect of L-NA (300 μmol/L, 30 min), diclofenac (Dl, 10 μmol/L, 30 min), the phospholipase A2 inhibitor AACOCF3 (AA, 3 μmol/L, 30 min), and the adenylyl cyclase inhibitor 2′,3′-dideoxyadenosine (DDA, 100 μmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. (c) Summary showing the effect of the AMPK inhibitor iodotubercidin (Iodo, 1 μmol/L, 30 min) and the phosphatidylinositol 3-kinase inhibitor wortmannin (Wort, 40 nmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. The results shown represent the mean ± SEM of data obtained in five to seven independent experiments. **P < 0.01 and ***P < 0.001 versus the response obtained using the supernatant from unstimulated platelets (Sol).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211801&req=5

fig2: Pharmacological characterization of the pathway involved in the insulin-induced release of a platelet-derived relaxing factor. (a) Effect of the guanylyl cyclase inhibitor, NS 2028 (NS, 10 μmol/L, 30 min), and the G kinase inhibitors, KT 5823 (KT, 1 μmol/L, 30 min) and Rp-8CPT-cGMPs (Rp, 10 μmol/L, 30 min), on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets, i.e., inhibitors applied to the platelet donor and the detector artery ring compared with the effects observed when the inhibitors were applied only to the detector ring. (b) Statistical summary showing the effect of L-NA (300 μmol/L, 30 min), diclofenac (Dl, 10 μmol/L, 30 min), the phospholipase A2 inhibitor AACOCF3 (AA, 3 μmol/L, 30 min), and the adenylyl cyclase inhibitor 2′,3′-dideoxyadenosine (DDA, 100 μmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. (c) Summary showing the effect of the AMPK inhibitor iodotubercidin (Iodo, 1 μmol/L, 30 min) and the phosphatidylinositol 3-kinase inhibitor wortmannin (Wort, 40 nmol/L, 30 min) on the insulin (1 μmol/L, 10 min)-induced release of a relaxing factor from washed human platelets. The results shown represent the mean ± SEM of data obtained in five to seven independent experiments. **P < 0.01 and ***P < 0.001 versus the response obtained using the supernatant from unstimulated platelets (Sol).
Mentions: When the soluble guanylyl cyclase inhibitor, NS2028 (10 μmol/L), or the G kinase inhibitors, KT 5823 (1 μmol/L) or Rp-8CPT-cGMPs (10 μmol/L), were present throughout the platelet stimulation and the organ chamber experiments, the relaxation of porcine coronary artery rings was significantly attenuated. However, when these compounds were present in the organ chamber but not present throughout the preparation of the platelet supernatant, no effect on the insulin-induced release of a platelet-derived relaxing factor was observed (Fig. 2 a).

Bottom Line: Insulin failed to relax endothelium-intact rings of porcine coronary artery.Insulin induced the release of adenosine trisphosphate (ATP), adenosine, and serotonin from platelet-dense granules in a NO-dependent manner.The mechanism of dense granule secretion involves the G kinase-dependent association of syntaxin 2 with vesicle-associated membrane protein 3.

View Article: PubMed Central - PubMed

Affiliation: Institut für Kardiovaskuläre Physiologie, Klinikum der J.W.Goethe-Universität, D-60590 Frankfurt am Main, Germany.

ABSTRACT
Insulin-induced vasodilatation is sensitive to nitric oxide (NO) synthase (NOS) inhibitors. However, insulin is unable to relax isolated arteries or to activate endothelial NOS in endothelial cells. Since insulin can enhance platelet endothelial NOS activity, we determined whether insulin-induced vasodilatation can be attributed to a NO-dependent, platelet-mediated process. Insulin failed to relax endothelium-intact rings of porcine coronary artery. The supernatant from insulin-stimulated human platelets induced complete relaxation, which was prevented by preincubation of platelets with a NOS inhibitor, the soluble guanylyl cyclase inhibitor, NS 2028, or the G kinase inhibitor, KT 5823, and was abolished by an adenosine A2A receptor antagonist. Insulin induced the release of adenosine trisphosphate (ATP), adenosine, and serotonin from platelet-dense granules in a NO-dependent manner. This response was not detected using insulin-stimulated platelets from endothelial NOS-/- mice, although a NO donor elicited ATP release. Insulin-induced ATP release from human platelets correlated with the association of syntaxin 2 with the vesicle-associated membrane protein 3 but was not associated with the activation of alphaIIbbeta3 integrin. Thus, insulin elicits the release of vasoactive concentrations of ATP and adenosine from human platelets via a NO-G kinase-dependent signaling cascade. The mechanism of dense granule secretion involves the G kinase-dependent association of syntaxin 2 with vesicle-associated membrane protein 3.

Show MeSH
Related in: MedlinePlus