Exogenous calmodulin potentiates vasodilation elicited by phospholipid-associated VIP in vivo

1999 ◽  
Vol 276 (5) ◽  
pp. R1359-R1365 ◽  
Author(s):  
Hiroyuki Ikezaki ◽  
Manisha Patel ◽  
Hayat Önyüksel ◽  
Syed R. Akhter ◽  
Xiao-Pei Gao ◽  
...  
Keyword(s):  
Active Sites ◽  
Calcium Ionophore ◽  
Cheek Pouch ◽  
Induced Responses ◽  
Hamster Cheek Pouch ◽  
Sterically Stabilized Liposomes ◽  
Extracellular Calmodulin ◽  
Peripheral Microcirculation

The purpose of this study was to determine whether exogenous calmodulin potentiates vasoactive intestinal peptide (VIP)-induced vasodilation in vivo and, if so, whether this response is amplified by association of VIP with sterically stabilized liposomes. Using intravital microscopy, we found that calmodulin suffused together with aqueous and liposomal VIP did not potentiate vasodilation elicited by VIP in the in situ hamster cheek pouch. However, preincubation of calmodulin with liposomal, but not aqueous, VIP for 1 and 2 h and overnight at 4°C before suffusion significantly potentiated vasodilation ( P < 0.05). Calmodulin-induced responses were significantly attenuated by calmidazolium, trifluoperazine, and N G-nitro-l-arginine methyl ester (l-NAME) but notd-NAME. The effects ofl-NAME were reversed byl- but notd-arginine. Indomethacin had no significant effects on calmodulin-induced responses. Calmodulin had no significant effects on adenosine-, isoproterenol-, acetylcholine-, and calcium ionophore A-23187-induced vasodilation. Collectively, these data indicate that exogenous calmodulin amplifies vasodilation elicited by phospholipid-associated, but not aqueous, VIP in the in situ peripheral microcirculation in a specific, calmodulin active sites-, and nitric oxide-dependent fashion. We suggest that extracellular calmodulin, phospholipids, and VIP form a novel functionally coordinated class of endogenous vasodilators.

scholarly journals Liposomal VIP attenuates phenylephrine- and ANG II-induced vasoconstriction in vivo

1998 ◽  
Vol 275 (2) ◽  
pp. R588-R595
Author(s):  
Hiroyuki Ikezaki ◽  
Hayat Önyüksel ◽  
Israel Rubinstein
Keyword(s):  
Calcium Ionophore ◽  
Cheek Pouch ◽  
Maximal Effect ◽  
Ang Ii ◽  
Hamster Cheek Pouch ◽  
Sterically Stabilized Liposomes ◽  
A 23187 ◽  
Α Helix

The purpose of this study was to determine whether vasoactive intestinal peptide (VIP) modulates vasoconstriction elicited by phenylephrine and ANG II in vivo and, if so, to begin to elucidate the mechanisms underlying this phenomenon. Using intravital microscopy, we found that suffusion of phenylephrine and ANG II elicits significant vasoconstriction in the in situ hamster cheek pouch that is potentiated by VIP-(10—28), a VIP receptor antagonist, but not by VIP-(1—12) ( P< 0.05). Aqueous VIP has no significant effects on phenylephrine- and ANG II-induced vasoconstriction. However, VIP on sterically stabilized liposomes (SSL), a formulation where VIP assumes a predominantly α-helix conformation, significantly attenuates this response. Maximal effect is observed within 30 min and is no longer seen after 60 min. Empty SSL are inactive. Indomethacin has no significant effects on responses induced by VIP on SSL. The vasodilators ACh, nitroglycerin, calcium ionophore A-23187, 8-bromo-cAMP, and isoproterenol have no significant effects on phenylephrine- and ANG II-induced vasoconstriction. Collectively, these data suggest that vasoconstriction modulates VIP release in the in situ hamster cheek pouch and that α-helix VIP opposes α-adrenergic- and ANG II-induced vasoconstriction in this organ in a reversible, prostaglandin-, NO-, cGMP-, and cAMP-independent fashion.

Vasodilation elicited by liposomal VIP is unimpeded by anti-VIP antibody in hamster cheek pouch

1998 ◽  
Vol 275 (1) ◽  
pp. R56-R62 ◽  
Author(s):  
Hiroyuki Ikezaki ◽  
Sudhir Paul ◽  
Hayat Alkan-Önyüksel ◽  
Manisha Patel ◽  
Xiao-Pei Gao ◽  
...  
Keyword(s):  
Calcium Ionophore ◽  
Myeloma Cell ◽  
Cheek Pouch ◽  
Myeloma Cell Line ◽  
Hamster Cheek Pouch ◽  
High Affinity ◽  
Sterically Stabilized Liposomes

The purpose of this study was to determine whether a monoclonal anti-vasoactive intestinal peptide (VIP) antibody, which binds VIP with high affinity and specificity and catalyzes cleavage of the peptide in vitro, attenuates VIP vasorelaxation in vivo and, if so, whether insertion of VIP on the surface of sterically stabilized liposomes (SSL), which protects the peptide from trypsin- and plasma-catalyzed cleavage in vitro, curtails this response. Using intravital microscopy, we found that suffusion of monoclonal anti-VIP antibody (clone c23.5, IgG2ak), but not of nonimmune antibody (myeloma cell line UPC10, IgG2ak) or empty SSL, significantly attenuates VIP-induced vasodilation in the in situ hamster cheek pouch ( P < 0.05). By contrast, anti-VIP antibody has no significant effects on vasodilation elicited by isoproterenol, nitroglycerin, and calcium ionophore A-23187, agonists that activate intracellular effector systems in blood vessels that mediate, in part, VIP vasoreactivity. Suffusion of VIP on SSL, but not of empty SSL, restores the vasorelaxant effects of VIP in the presence of anti-VIP antibody. Collectively, these data suggest that VIP catalysis by high affinity and specific VIP autoantibodies displaying protease-like activity constitutes a novel mechanism whereby VIP vasoreactivity is regulated in vivo.

Mechanisms of vasodilation elicited by VIP in sterically stabilized liposomes in vivo

1997 ◽  
Vol 273 (1) ◽  
pp. R287-R292 ◽  
Author(s):  
F. Sejourne ◽  
H. Suzuki ◽  
H. Alkan-Onyuksel ◽  
X. P. Gao ◽  
H. Ikezaki ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Cheek Pouch ◽  
Similar Response ◽  
Hamster Cheek Pouch ◽  
Amino Terminal ◽  
Sterically Stabilized Liposomes ◽  
Peripheral Microcirculation ◽  
Synthase Inhibitor

The purpose of this study was to begin to determine the mechanisms underlying vasodilation elicited by vasoactive intestinal peptide (VIP) in sterically stabilized liposomes (SSL) in the in situ peripheral microcirculation. Using intravital microscopy, we found that suffusion of VIP in SSL (0.42 and 0.85 nmol) onto the hamster cheek pouch for 1 h elicited significant and prolonged concentration-dependent vasodilation (P < 0.05). Suffusion of VIP in SSL (0.1 nmol) for 7 min elicited a qualitatively similar response, although its magnitude was significantly smaller than that elicited by 1 h of suffusion of VIP in SSL (P < 0.05). The VIP-receptor antagonist VIP-(10-28), but not the amino-terminal fragment VIP-(1-12), significantly attenuated and delayed the onset of VIP in SSL-induced vasodilation (P < 0.05). The nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), but not NG-nitro-D-arginine methyl ester (D-NAME), abrogated VIP in SSL-induced responses. We conclude that VIP in SSL elicits significant and prolonged vasodilation in the in situ peripheral microcirculation, which is specific, partly receptor dependent, and partly transduced by the L-arginine/NO biosynthetic pathway.

scholarly journals Mechanisms Mediating Porphyromonas gingivalis Gingipain RgpA-Induced Oral Mucosa Inflammation In Vivo

2001 ◽  
Vol 69 (2) ◽  
pp. 1199-1201 ◽  
Author(s):  
Israel Rubinstein ◽  
Jan Potempa ◽  
James Travis ◽  
Xiao-Pei Gao
Keyword(s):  
Oral Mucosa ◽  
Porphyromonas Gingivalis ◽  
Proteinase Inhibitors ◽  
Cheek Pouch ◽  
Induced Responses ◽  
Hamster Cheek Pouch ◽  
Plasma Exudation ◽  
Significant Concentration

ABSTRACT Suffusion of gingipain RgpA (GRgpA) elicited a significant concentration-dependent increase in the clearance of macromolecules from in situ hamster cheek pouch which was attenuated by NPC 17647, a selective bradykinin B2 receptor antagonist. Leupeptin and a mixture of proteinase inhibitors also attenuated GRgpA-induced responses. These data indicate that GRgpA elicits plasma exudation from in situ oral mucosa in a catalytic site-dependent fashion by elaborating bradykinin.

Peptidases modulate bradykinin-induced arteriolar dilation in the hamster cheek pouch

1994 ◽  
Vol 266 (1) ◽  
pp. H93-H98 ◽  
Author(s):  
X. P. Gao ◽  
P. Anding ◽  
R. A. Robbins ◽  
S. I. Rennard ◽  
I. Rubinstein
Keyword(s):  
Proteinase Inhibitors ◽  
Neutral Endopeptidase ◽  
Cheek Pouch ◽  
Induced Responses ◽  
Hamster Cheek Pouch ◽  
Before And After ◽  
Peripheral Microcirculation ◽  
Membrane Bound ◽  
Arteriolar Diameter

The purpose of this study was to investigate whether angiotensin-converting enzyme (ACE; EC 3.4.15.1) and neutral endopeptidase (NEP; EC 3.4.24.11), two membrane-bound metalloenzymes that are widely distributed in the peripheral microcirculation and degrade kinins very effectively, modulate bradykinin-induced arteriolar dilation in vivo. Using intravital microscopy, we measured diameter of second-order arterioles in the hamster cheek pouch during suffusion of bradykinin (0.1–10.0 microM) before and after topical application of captopril (10.0 microM) and phosphoramidon (10.0 nM). We found that each inhibitor significantly potentiated bradykinin-induced increase in arteriolar diameter (P < 0.05). Suffusion of other proteinase inhibitors (excluding ACE and NEP inhibitors) had no significant effect on bradykinin-induced responses. Captopril and phosphoramidon did not potentiate isoproterenol (0.1 microM)-induced arteriolar dilation in the cheek pouch. Collectively, these data indicate that ACE and NEP each plays an important role in regulating bradykinin-induced vasorelaxation in the peripheral microcirculation in vivo.

Tannic acid elicits neurogenic plasma exudation from the in situ hamster cheek pouch

1998 ◽  
Vol 274 (1) ◽  
pp. R237-R242
Author(s):  
Xiao-Pei Gao
Keyword(s):  
Tannic Acid ◽  
Biosynthetic Pathway ◽  
Fluorescein Isothiocyanate ◽  
Cheek Pouch ◽  
Site Formation ◽  
Hamster Cheek Pouch ◽  
Plasma Exudation ◽  
Synthase Inhibitor

The purpose of this study was to determine whether tannic acid elicits neurogenic plasma exudation from the oral mucosa in vivo and, if so, whether this response is transduced in part by thel-arginine-nitric oxide (NO) biosynthetic pathway. Using intravital microscopy, we found that suffusion of tannic acid elicits significant concentration-dependent leaky site formation and increase in clearance of fluorescein isothiocyanate-dextran (molecular mass 70 kDa) from the in situ hamster cheek pouch ( P < 0.05). These effects are significantly attenuated by two selective, but structurally distinct, nonpeptide neurokinin-1 (NK1) receptor antagonists, CP-96,345 and RP-67580, but not by CP-96,344, the 2R,3R enantiomer of CP-96,345. N G-nitrol-arginine methyl ester (l-NAME), an NO synthase inhibitor, but notd-NAME, significantly attenuates tannic acid-induced responses.l-Arginine, but notd-arginine, reverses the attenuating effects of l-NAME. We conclude that tannic acid elicitsl-arginine-NO biosynthetic pathway-dependent neurogenic plasma exudation from the in situ hamster cheek pouch.

Neutral endopeptidase modulates substance P-induced vasodilation in vivo

1995 ◽  
Vol 78 (2) ◽  
pp. 562-568 ◽  
Author(s):  
X. P. Gao ◽  
I. Rubinstein
Keyword(s):  
Substance P ◽  
Oral Mucosa ◽  
Intravital Microscopy ◽  
Neutral Endopeptidase ◽  
Cheek Pouch ◽  
Induced Responses ◽  
Hamster Cheek Pouch ◽  
Arteriolar Diameter ◽  
Significant Concentration

The purpose of this study was to investigate whether neutral endopeptidase (NEP; EC 3.4.24.11) modulates substance P-induced vasodilation in the oral mucosa in vivo. Using intravital microscopy, we measured the diameter of second-order arterioles (44–70 microns) in the hamster cheek pouch during suffusion of capsaicin and substance P. We found that capsaicin (0.1 and 10.0 nM) induced significant concentration-dependent vasodilations (13 +/- 4 and 39 +/- 7% increase from baseline, respectively; P < 0.05) that were significantly potentiated by phosphoramidon (10.0 nM), a selective NEP inhibitor (35 +/- 15 and 61 +/- 12% increase from baseline, respectively; P < 0.05). Substance P (0.1 and 10.0 nM) also induced significant concentration-dependent vasodilations (7 +/- 3 and 25 +/- 8% increase from baseline, respectively; P < 0.05) that were mediated by the COOH-terminal of the molecule. Substance P-induced responses were significantly potentiated by phosphoramidon (34 +/- 9 and 53 +/- 10% increase from baseline, respectively; P < 0.05) and thiorphan (10.0 microM), a selective NEP inhibitor (44 +/- 11 and 53 +/- 10% increase from baseline, respectively; P < 0.05). Substance P-(1–9) had no significant effects on arteriolar diameter. Suffusion of captopril, leupeptin, Bestatin, and DL-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid together had no significant effects on substance P-induced vasodilation. Phosphoramidon did not potentiate nitroglycerin-induced vasodilation. These data indicate that NEP modulates substance P-induced vasodilation in the hamster cheek pouch in vivo. We suggest that any decrease in tissue NEP activity may amplify neurogenic vasodilation in the oral mucosa.

scholarly journals Dexamethasone attenuates acute macromolecular efflux increase evoked by smokeless tobacco extract

1999 ◽  
Vol 87 (2) ◽  
pp. 619-625 ◽  
Author(s):  
Xiao-Pei Gao ◽  
Syed R. Akhter ◽  
Hiroyuki Ikezaki ◽  
Dennis Hong ◽  
Israel Rubinstein
Keyword(s):  
Oral Mucosa ◽  
Smokeless Tobacco ◽  
Fluorescein Isothiocyanate ◽  
Cheek Pouch ◽  
Site Formation ◽  
Hamster Cheek Pouch ◽  
Acute Increase ◽  
Tobacco Extract

The purpose of this study was to determine whether dexamethasone attenuates the acute increase in macromolecular efflux from the oral mucosa elicited by an aqueous extract of smokeless tobacco (STE) in vivo, and, if so, whether this response is specific. Using intravital microscopy, we found that 20-min suffusion of STE elicited significant, concentration-related leaky site formation and an increase in clearance of fluorescein isothiocyanate-labeled dextran (FITC-dextran; mol mass 70 kDa) from the in situ hamster cheek pouch ( P < 0.05). This response was significantly attenuated by dexamethasone (10 mg/kg iv). Dexamethasone also attenuated the bradykinin-induced leaky site formation and the increase in clearance of FITC-dextran from the cheek pouch. However, it had no significant effects on adenosine-induced responses. Dexamethasone had no significant effects on baseline arteriolar diameter and on bradykinin-induced vasodilation in the cheek pouch. Collectively, these data indicate that dexamethasone attenuates, in a specific fashion, the acute increase in macromolecular efflux from the in situ oral mucosa evoked by short-term suffusion of STE. We suggest that corticosteroids mitigate acute oral mucosa inflammation elicited by smokeless tobacco.

Loop diuretics attenuate bradykinin-induced increase in clearance of macromolecules in the oral mucosa

1996 ◽  
Vol 80 (3) ◽  
pp. 818-823 ◽  
Author(s):  
X. P. Gao ◽  
J. M. Conlon ◽  
J. K. Vishwanatha ◽  
R. A. Robbins ◽  
I. Rubinstein
Keyword(s):  
Oral Mucosa ◽  
Fluorescein Isothiocyanate ◽  
Loop Diuretics ◽  
Cheek Pouch ◽  
Site Formation ◽  
Induced Responses ◽  
Vasomotor Tone ◽  
Hamster Cheek Pouch ◽  
Significant Concentration

The purpose of this study was to determine whether loop diuretics attenuate bradykinin-induced increase in clearance of macromolecules in the oral mucosa in situ and, if so, to start to determine the mechanisms that mediated these responses. By using intravital microscopy, we found that bradykinin induced a significant concentration-dependent increase in fluorescein isothiocyanate-labeled dextran (mol mass 70 kDa) leaky site formation in the hamster cheek pouch. These responses were significantly attenuated by topical application of two structurally distinct loop diuretics, furosemide and ethacrynic acid, onto the cheek pouch (P < 0.05). Hydrochlorothiazide, a nonloop diuretic, had no significant effects on bradykinin-induced responses. Furosemide had no significant effects on adenosine-induced leaky site formation. Application of bradykinin after furosemide, but not after hydrochlorothiazide, was associated with a significant concentration-dependent decrease in bradykinin-like immunoreactivity in the cheek pouch suffusate (P < 0.05). Prostaglandins and changes in vasomotor tone did not modulate the effects of furosemide on bradykinin-induced responses. These data indicate that loop diuretics attenuate bradykinin-induced increase in clearance of macromolecules in the oral mucosa in a specific fashion, probably by amplifying local bradykinin catabolism. We suggest that topical loop diuretics could be useful in the treatment of oral mucosa inflammation elicited by bradykinin.

Stable VIP analogue Ro-24-9981 potentiates substance P-induced plasma exudation in hamster cheek pouch

1995 ◽  
Vol 79 (3) ◽  
pp. 968-974 ◽  
Author(s):  
X. P. Gao ◽  
H. A. Jaffe ◽  
C. O. Olopade ◽  
I. Rubinstein
Keyword(s):  
Methyl Ester ◽  
Substance P ◽  
Calcium Ionophore ◽  
Fluorescein Isothiocyanate ◽  
No Synthase ◽  
Cheek Pouch ◽  
Site Formation ◽  
Induced Responses ◽  
Hamster Cheek Pouch ◽  
Plasma Exudation

The purpose of this study was to determine whether vasoactive intestinal peptide (VIP; 300 nM) and a stable cyclic analogue of VIP, Ro-24–9981 (226 nM), modulated neurogenic plasma exudation in the oral cavity in situ and, if so, to determine the mechanisms that mediated these responses. With the use of intravital microscopy, we found that suffusion of substance P induced a significant concentration-dependent formation of fluorescein-isothiocyanate-dextran (mol wt 70 kDa) leaky sites in the hamster cheek pouch (P < 0.05). These effects were significantly and stereospecifically attenuated by NG-nitro-L-arginine methyl ester, an inhibitor of NO synthase, and restored by L-arginine, the substrate for NO synthase (P < 0.05). Topical application of human VIP and Ro-24–9981 had no significant effects of leaky site formation. In addition, human VIP had no significant effects on substance P-induced responses. By contrast, Ro-24–9981 significantly potentiated substance P- and capsaicin-induced leaky site formation (P < 0.05). The effects of Ro-24–9981 on substance P-induced responses were significantly attenuated by NG-nitro-L-arginine methyl ester and restored by L-arginine (P < 0.05). Indomethacin had no significant effects on Ro-24–9981-induced responses. Ro-24–9981 had no significant effects on adenosine- and calcium ionophore A-23187-induced leaky site formation. Collectively, these data suggest that VIP plays no significant role in modulating neurogenic plasma exudation in the oral mucosa. By contrast, Ro-24–9981 amplified this response in a specific receptor-mediated fashion.

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