Abstract
Several lines of evidence indicate that insulin-like growth factor-I (IGF- I) is a potent mediator of vasodilation. To elucidate the mechanism and site of action of IGF-I, we performed continuous monitoring of nitric oxide (NO) release from endothelial cells using a highly-sensitive amperometric NO- sensor. Two types of cultured cells were used: human umbilical vein endothelial cells and immortalized rat renal interlobar artery endothelial cells. In separate experiments, [Ca2+](i) changes in response to IGF-I were measured spectrofluorometrically in fura-2-loaded cells. Stimulation with IGF-I resulted in a rapid, dose-dependent increase in [NO] as detected by the NO-probe positioned 1 mm above the monolayers, followed by a sustained elevation lasting for at least five minutes. The effect of IGF-I was significantly suppressed by pretreatment with anti-IGF-I antibody, suggesting that it was specific for IGF-I. N(G)-nitro-L-arginine methyl ester, an inhibitor of NO synthesis, significantly blunted responses to IGF-I, but dexamethasone preincubation did not reduce the IGF-I-induced release of NO. These results indicate that the observed IGF-I-induced release of NO is a result of activation of the constitutive, rather than the inducible type of NO synthase in endothelial cells. Genistein, a tyrosine kinase inhibitor, resulted in a profound suppression of the IGF-I-induced release of NO. IGF-I did not affect [Ca2+](i) in either types of cells. Therefore, IGF-I- induced NO production by both types of endothelial cells is mediated via a tyrosine kinase-dependent mechanism. IGF-I may be an important regulator of vascular tone in vivo through NO release from the vascular endothelium, and may contribute to the regulation of renal blood flow under physiological and pathophysiological conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 598-604 |
| Number of pages | 7 |
| Journal | Kidney International |
| Volume | 45 |
| Issue number | 2 |
| Publication status | Published - Feb 1994 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Nephrology
Cite this
Direct demonstration of insulin-like growth factor-I-induced nitric oxide production by endothelial cells. / Tsukahara, Hirokazu; Gordienko, Dmitri V.; Tonshoff, Burkhard; Gelato, Marie C.; Goligorsky, Michael S.
In: Kidney International, Vol. 45, No. 2, 02.1994, p. 598-604.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct demonstration of insulin-like growth factor-I-induced nitric oxide production by endothelial cells
AU - Tsukahara, Hirokazu
AU - Gordienko, Dmitri V.
AU - Tonshoff, Burkhard
AU - Gelato, Marie C.
AU - Goligorsky, Michael S.
PY - 1994/2
Y1 - 1994/2
N2 - Several lines of evidence indicate that insulin-like growth factor-I (IGF- I) is a potent mediator of vasodilation. To elucidate the mechanism and site of action of IGF-I, we performed continuous monitoring of nitric oxide (NO) release from endothelial cells using a highly-sensitive amperometric NO- sensor. Two types of cultured cells were used: human umbilical vein endothelial cells and immortalized rat renal interlobar artery endothelial cells. In separate experiments, [Ca2+](i) changes in response to IGF-I were measured spectrofluorometrically in fura-2-loaded cells. Stimulation with IGF-I resulted in a rapid, dose-dependent increase in [NO] as detected by the NO-probe positioned 1 mm above the monolayers, followed by a sustained elevation lasting for at least five minutes. The effect of IGF-I was significantly suppressed by pretreatment with anti-IGF-I antibody, suggesting that it was specific for IGF-I. N(G)-nitro-L-arginine methyl ester, an inhibitor of NO synthesis, significantly blunted responses to IGF-I, but dexamethasone preincubation did not reduce the IGF-I-induced release of NO. These results indicate that the observed IGF-I-induced release of NO is a result of activation of the constitutive, rather than the inducible type of NO synthase in endothelial cells. Genistein, a tyrosine kinase inhibitor, resulted in a profound suppression of the IGF-I-induced release of NO. IGF-I did not affect [Ca2+](i) in either types of cells. Therefore, IGF-I- induced NO production by both types of endothelial cells is mediated via a tyrosine kinase-dependent mechanism. IGF-I may be an important regulator of vascular tone in vivo through NO release from the vascular endothelium, and may contribute to the regulation of renal blood flow under physiological and pathophysiological conditions.
AB - Several lines of evidence indicate that insulin-like growth factor-I (IGF- I) is a potent mediator of vasodilation. To elucidate the mechanism and site of action of IGF-I, we performed continuous monitoring of nitric oxide (NO) release from endothelial cells using a highly-sensitive amperometric NO- sensor. Two types of cultured cells were used: human umbilical vein endothelial cells and immortalized rat renal interlobar artery endothelial cells. In separate experiments, [Ca2+](i) changes in response to IGF-I were measured spectrofluorometrically in fura-2-loaded cells. Stimulation with IGF-I resulted in a rapid, dose-dependent increase in [NO] as detected by the NO-probe positioned 1 mm above the monolayers, followed by a sustained elevation lasting for at least five minutes. The effect of IGF-I was significantly suppressed by pretreatment with anti-IGF-I antibody, suggesting that it was specific for IGF-I. N(G)-nitro-L-arginine methyl ester, an inhibitor of NO synthesis, significantly blunted responses to IGF-I, but dexamethasone preincubation did not reduce the IGF-I-induced release of NO. These results indicate that the observed IGF-I-induced release of NO is a result of activation of the constitutive, rather than the inducible type of NO synthase in endothelial cells. Genistein, a tyrosine kinase inhibitor, resulted in a profound suppression of the IGF-I-induced release of NO. IGF-I did not affect [Ca2+](i) in either types of cells. Therefore, IGF-I- induced NO production by both types of endothelial cells is mediated via a tyrosine kinase-dependent mechanism. IGF-I may be an important regulator of vascular tone in vivo through NO release from the vascular endothelium, and may contribute to the regulation of renal blood flow under physiological and pathophysiological conditions.
UR - http://www.scopus.com/inward/record.url?scp=0027976585&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027976585&partnerID=8YFLogxK
M3 - Article
C2 - 7513035
AN - SCOPUS:0027976585
VL - 45
SP - 598
EP - 604
JO - Kidney International
JF - Kidney International
SN - 0085-2538
IS - 2
ER -