Impact of parainfluenza-3 virus infection on endothelin receptor density and function in guinea pig airways

2002 ◽  
Vol 103 (s2002) ◽  
pp. 345S-348S ◽  
Author(s):  
Angela C. D'APRILE ◽  
Lynette B. FERNANDES ◽  
Paul J. RIGBY ◽  
Roy G. GOLDIE
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Binding Sites ◽  
Specific Binding ◽  
Tracheal Smooth Muscle ◽  
Receptor Subtypes ◽  
Post Inoculation ◽  
Receptor Density ◽  
And Function ◽  
The Impact

We examined the impact of parainfluenza-3 (P-3) respiratory tract viral infection on the density and function of endothelin (ET) receptor subtypes (ETA and ETB) in guinea pig tracheal smooth muscle. Total specific binding of [125I]ET-1 and the relative proportions of ETA and ETB binding sites for this ligand were assessed at day 0 (control) and at 2, 4, 8 and 16 days post-inoculation. At day 0, the proportions of ETA and ETB binding sites were 30% and 70% respectively. Total specific binding was significantly reduced at day 4 post-inoculation (32% reduction, n = 8–12, P<0.05) and was largely due to a corresponding fall in ETB receptor density at this time point (38% reduction, n = 8–12, P<0.05). The density of ETA receptors also fell significantly at day 8 post-inoculation (33% reduction, n = 6–12, P<0.05). By day 16 post-inoculation, the densities of ETA and ETB receptors had recovered to control values. The ratio of ETA:ETB receptor subtypes did not alter with P-3 infection. While P-3 infection reduced the density of tracheal smooth muscle ETA and ETB receptors, the contractile sensitivity and maximum response to carbachol and ET-1 was not altered in tissue from day 4 post-inoculation compared with the control. There seems to be a significant functional reserve for both receptor subtypes in this species that buffers the impact of P-3 infection on airway smooth muscle responsiveness to ET-1.

Receptors for substance P on isolated intestinal smooth muscle cells of the guinea pig

1987 ◽  
Vol 253 (5) ◽  
pp. G666-G672
Author(s):  
J. C. Souquet ◽  
K. N. Bitar ◽  
J. R. Grider ◽  
G. M. Makhlouf
Keyword(s):  
Smooth Muscle ◽  
Substance P ◽  
Guinea Pig ◽  
Smooth Muscle Cells ◽  
Binding Sites ◽  
Specific Binding ◽  
Muscle Cells ◽  
Receptor Subtype ◽  
Longitudinal Muscle Layer ◽  
Substance K

Two radioligands, 125I-labeled substance P (125I-SP) and 125I-labeled substance K (125I-SK), were used to characterize the kinetics and stoichiometry of binding of mammalian tachykinins [substance P (SP), substance K (SK), and neuromedin K (NK)] to smooth muscle cells isolated from the longitudinal muscle layer of guinea pig intestine. Specific binding of 125I-SP and 125I-SK was rapid, saturable, reversible, and temperature dependent. Binding attained 63-70% of steady-state binding within 1 min, coincidentally with the time of optimal contraction. The order of potency with which mammalian tachykinins and the SP antagonist, [D-Pro2, D-Trp7,9]SP, inhibited the binding of both radioligands was identical: SP greater than SK greater than NK greater than [D-Pro2, D-Trp7,9]SP, implying preferential interaction with a site that had highest affinity for SP. SK was 2-3 times, NK 3-4 times, and [D-Pro2, D-Trp7,9]SP 7-23 times less potent than SP (IC50 0.36 nM). Except for NK, the order of potency was similar to that for contraction of isolated muscle cells. The existence of binding sites with even higher affinity was suggested by the ability of muscle cells to contract in response to concentrations as low as 10(-13) M. These binding sites were not detectable at the concentration of radioligands used. It was concluded that a SP receptor is the only tachykinin receptor subtype present on intestinal muscle cells of the guinea pig.

Leptin induces a contracting effect on guinea pig tracheal smooth muscle via the Ob-R receptor mechanism: novel evidence

2020 ◽  
Vol 98 (11) ◽  
pp. 810-817
Author(s):  
Aamir Magzoub ◽  
Mohammed Al-Ayed ◽  
Ibrahim Ahmed Shaikh ◽  
Mohamed Shafiuddin Habeeb ◽  
Khalid Al-Shaibary ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Leptin Receptor ◽  
Smooth Muscles ◽  
Tracheal Smooth Muscle ◽  
Organ Bath ◽  
Data Acquisition Software ◽  
Passive Sensitization ◽  
The Impact

The purpose of this study was to explore the potential contracting effect of leptin on isolated guinea pig tracheal smooth muscle (TSM), the possible mechanism, and the impact of epithelium denudation or allergen sensitization, respectively. An in vitro experiment investigated the effect of leptin at a concentration of 250–1000 nmol/L on isolated guinea pig TSM with an intact or denuded epithelium. Ovalbumin and IgE were used to test the impact of active and passive sensitization. The isolated TSM strips were incubated in Krebs solution and aerated with carbogen (95% O2 and 5% CO2) via an automated tissue organ bath system (n = 4 for each group). Isometric contractions were recorded digitally using iox2 data acquisition software. The possible mechanism of leptin-induced TSM contraction was examined by preincubation with leptin receptor (Ob-R) antagonist. Leptin had significant concentration-dependent contraction effects on guinea pig TSM (p < 0.05). Epithelium denuding and active or passive sensitization significantly increased the potency of the leptin. Preincubation with a leptin receptor (Ob-R) antagonist significantly reduced the contraction effects, suggesting an Ob-R-mediated mechanism. Leptin had a contracting effect on airway smooth muscles potentiated by either epithelium denuding or sensitization, and the Ob-R mechanism was a possible effect mediator.

Characterization of kinin binding sites: identity of B2 receptors in the epithelium and the smooth muscle of the guinea pig ileum

1991 ◽  
Vol 69 (6) ◽  
pp. 818-825 ◽  
Author(s):  
C. Tousignant ◽  
G. Guillemette ◽  
J. Barabé ◽  
N.-E. Rhaleb ◽  
D. Regoli
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cell ◽  
Guinea Pig ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Binding Sites ◽  
Cell Membranes ◽  
Specific Binding ◽  
Scatchard Analysis ◽  
Guinea Pig Ileum

Binding of [125I-Tyr8]bradykinin (BK) was measured in homogenates of epithelial and smooth muscle layers of the guinea pig ileum. Binding assays were performed at 4 °C for 40 min (smooth muscle) or 90 min (epithelium) in 25 mM PIPES buffer at pH 6.8 in the presence of 1 mM 1,10-phenanthroline, 140 μg/mL bacitracin, 1 mM captopril, 1 mM dithiothreitol, and 0.1% bovine serum albumin. Specific binding of [125I-Tyr8]BK (0.32 nM) to epithelial and smooth muscle cell membranes was linearly related to protein concentration between 0.05 and 0.5 mg/mL. Equilibrium experiments showed that specific binding of [125I-Tyr8]BK was saturable and Scatchard analysis indicated the presence of a high affinity site with a Kd value of 1.6 nM and a Bmax. of 156 fmol/mg of protein in the epithelial cell membranes. In smooth muscle membranes, Kd was 1.8 nM and the maximum number of binding sites was 58 fmol/mg of protein. Unlabelled peptides, namely bradykinin, [Tyr8]BK, [Hyp3]BK, D-Arg[Hyp3]BK, [Hyp3,Tyr(Me8)]BK, and kallidin displaced [125I-Tyr8]BK binding while other peptides, angiotensin II and substance P, had no effect. A series of B2-receptor antagonists displaced [125I-Tyr8]BK from specific binding sites with IC50 values ranging from 16 to 152 nM on epithelial cell membranes; similar values were obtained from smooth muscle cell membranes. These findings suggest that the binding sites in both preparations are of the B2 type. B1-receptor agonists and antagonists were found to be inactive at concentrations up to 10−4 M. Results obtained in the two preparations were compared and a positive highly significant correlation was demonstrated between the two sets of data. It is therefore concluded that B2 receptors found in the epithelium and the smooth muscle membranes of the guinea pig ileum are identical. These sites are similar to the functional receptor mediating the myotropic effect of bradykinin in the ileum.Key words: kinins, epithelium, smooth muscle, guinea pig ileum, binding and biological assays.

scholarly journals Are there subtypes of the inositol 1,4,5-trisphosphate receptor?

1990 ◽  
Vol 269 (1) ◽  
pp. 211-216 ◽  
Author(s):  
M A Varney ◽  
J Rivera ◽  
A Lopez Bernal ◽  
S P Watson
Keyword(s):  
Smooth Muscle ◽  
Adrenal Cortex ◽  
Binding Sites ◽  
Inositol Phosphates ◽  
Specific Binding ◽  
Species Difference ◽  
Circular Muscle ◽  
Receptor Subtypes ◽  
Uterine Smooth Muscle ◽  
Similar Affinity

We have compared the properties of the [3H]Ins(1,4,5)P3-binding sites from a number of tissues in an attempt to determine if heterogeneity exists within the Ins(1,4,5)P3-receptor family. The binding of Ins(1,4,5)P3 was characterized in detail by using membranes prepared from human uterine smooth muscle and bovine adrenal cortex. Ins(1,4,5)P3 exhibited an approx. 5 times greater affinity for the binding site in adrenal cortex (KD = 9.81 +/- 1.92 nM) compared with uterine smooth muscle (KD = 37.1 +/- 1.8 nM). The binding was dependent on pH in both tissues, with a maximum at pH 8.3; at this pH various inositol phosphates and nucleotides competed for the binding sites with similar potencies on both tissues. However, the binding of Ins(1,4,5)P3 to the uterine smooth-muscle membranes was Ca2(+)-sensitive, whereas that to the bovine adrenal cortex was not; furthermore, heparin displaced the binding of Ins(1,4,5)P3 in the uterus with an IC50 value (concn. of displacer giving 50% inhibition of specific binding) of 3.9 micrograms/ml (2.5, 6.4; lower, upper range), compared with a value of 22 (13, 30) micrograms/ml in adrenal cortex. In view of the ability of Ins(1,4,5)P3 and heparin to distinguish between these binding sites, their effect on other tissues was examined. Ins(1,4,5)P3 showed a similar affinity for receptors located in the bovine cerebellum to those in the bovine adrenal cortex, but heparin displaced Ins(1,4,5)P3 binding with a 5-fold greater affinity from the cerebellum. Ins(1,4,5)P3 had a 2-fold greater affinity for its receptor with human platelets, as compared with human uterus, but heparin was unable to distinguish between these sites. In guinea-pig ileum, Ins(1,4,5)P3 displayed a similar affinity for the receptors in the longitudinal muscle compared with the circular muscle, but heparin could distinguish between these sites. These data show that small differences exist between tissues, but no clear picture is apparent. It is possible that these results reflect tissue-dependent factors such as phosphorylation, the presence of calmedin etc., rather than the presence of receptor subtypes or species difference.

Relationship between potency of L-isoprenaline and β-adrenoceptor density estimated in single cells from tracheal smooth muscles of guinea pigs of different ages

1992 ◽  
Vol 70 (4) ◽  
pp. 458-461 ◽  
Author(s):  
Issei Takayanagi ◽  
Mitsutoshi Satoh ◽  
Noriko Kokubu ◽  
Teruko Kato
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Dissociation Constants ◽  
Specific Binding ◽  
Single Cells ◽  
Regression Line ◽  
Smooth Muscles ◽  
Receptor Density ◽  
Age Related ◽  
Β Receptor

An age-related change in potency of L-isoprenaline in the presence of ascorbic acid, desmethylimipramine, corticosterone, pargyline, and phentolamine was obtained in tracheal strips from guinea pigs of differing ages between 6 and 40 weeks. The potency in the strips from 100-week-old guinea pigs did not significantly differ from that in strips from 40-week-old animals. Single cells were prepared from the tracheal muscles of 6-, 10-, 40-, and 100-week-old guinea pigs. The specific binding of [3H]dihydroalprenolol to the single cells was saturable. The dissociation constants of [3H]dihydroalprenolol were in good agreement with those of the membrane fractions from the guinea-pig tracheal muscles, and did not change with age. An excellent relationship between the potency of L-isoprenaline and the maximum binding of [3H]dihydroalprenolol estimated in the preparations from 6- to 40-week-old guinea pigs was found, suggesting that the increase in the potency of L-isoprenaline is due to the increase in the maximum binding or receptor density. The value in the preparations from 100-week-old guinea pigs deviated significantly from the regression line. This suggests the possibility that the decrease in potency in the strips from 100-week-old animals is due to a change in post β-receptor processes in responsiveness.Key words: guinea-pig trachea, single cells, β-receptor density, ageing, dissociation constant.

scholarly journals l-NG-nitro arginine inhibits non-adrenergic, non-cholinergic relaxations of guinea-pig isolated tracheal smooth muscle

1990 ◽  
Vol 100 (4) ◽  
pp. 663-664 ◽  
Author(s):  
John F. Tucker ◽  
Sandra R. Brave ◽  
Litsa Charalambous ◽  
Adrian J. Hobbs ◽  
Alan Gibson
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Tracheal Smooth Muscle

Effect of SR-49059, a vasopressin V1a antagonist, on human vascular smooth muscle cells

1995 ◽  
Vol 268 (1) ◽  
pp. H404-H410 ◽  
Author(s):  
C. Serradeil-Le Gal ◽  
J. M. Herbert ◽  
C. Delisee ◽  
P. Schaeffer ◽  
D. Raufaste ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Specific Binding ◽  
Muscle Cells ◽  
Maximal Response ◽  
Receptor Subtypes ◽  
Functional Studies ◽  
Antagonist Binding

The effects of SR-49059, a new nonpeptide and selective arginine vasopressin (AVP) V1a antagonist, were investigated in binding and functional studies on cultured human aortic vascular smooth muscle cells (VSMC). Characterization of human vascular V1a receptors, using a specific V1a radioiodinated ligand, showed that [125I]-linear AVP antagonist binding to human VSMC membranes was time dependent, reversible, and saturable. A single population of high-affinity binding sites (apparent equilibrium dissociation constant = 15 +/- 6 pM; maximum binding density = 36 +/- 5 fmol/mg protein, i.e., approximately 3,000 sites/cell) with the expected V1a profile was identified. Exposure of these cells to AVP dose-dependently produced cytosolic free [Ca2+] increase [AVP concentration required to obtain a half-maximal response (EC50) = 23 +/- 9 nM] and proliferation (EC50 = 3.2 +/- 0.5 nM). SR-49059 strongly and stereospecifically inhibited [125I]-linear AVP antagonist binding to VSMC V1a receptors [inhibition constant (Ki) = 1.4 +/- 0.3 nM], AVP-evoked Ca2+ increase [concentration of inhibitor required to obtain 50% inhibition of specific binding (IC50) = 0.41 +/- 0.06 nM], and the mitogenic effects induced by 100 nM AVP (IC50 = 0.83 +/- 0.04 nM). OPC-21268, another nonpeptide V1a antagonist, was more than two orders of magnitude less potent than SR-49059 in these models. However, the consistent affinity (Ki = 138 +/- 21 nM) and activity found with OPC-21268 on human VSMC in comparison with the inactivity already observed for other human V1a receptors (liver, platelets, adrenals, and uterus) strongly suggested the existence of human AVP V1a-receptor subtypes.(ABSTRACT TRUNCATED AT 250 WORDS)

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