Renal tubular vasopressin receptors downregulated by dehydration

1988 ◽  
Vol 254 (3) ◽  
pp. C404-C410 ◽  
Author(s):  
M. Steiner ◽  
M. I. Phillips
Keyword(s):  
Binding Sites ◽  
Plasma Osmolality ◽  
Fold Increase ◽  
Scatchard Analysis ◽  
Sprague Dawley ◽  
Single Class ◽  
Physiological Regulation ◽  
Lysine Vasopressin ◽  
Vasopressin Receptors ◽  
Renal Tubular

Receptors for arginine vasopressin (AVP) were characterized in tubular epithelial basolateral membranes (BL membranes) prepared from the kidneys of male Sprague-Dawley rats. Association of [3H]AVP was rapid, reversible, and specific. Saturation studies revealed a single class of saturable binding sites with a maximal binding (Bmax) of 184 +/- 15 fmol/mg protein and a KD of 0.61 +/- 0.04 nM. IC50S for AVP, lysine vasopressin, and oxytocin were 0.74 nM, 9.7 nM, and greater than 1 microM, respectively. The V2 receptor antagonist was more than 3,700 times as effective in displacing [3H]AVP than was the V1 antagonist. To investigate the physiological regulation of vasopressin receptors, the effects of elevated levels of circulating AVP on receptor characteristics were studied. Seventy-two-hour water deprivation significantly elevated plasma osmolality and caused an 11.5-fold increase in plasma [AVP]. Scatchard analysis revealed a 38% decrease in the number of AVP receptors on the BL membranes from dehydrated animals. The high-affinity binding sites on the BL membranes fit the pharmacological profile for adenylate cyclase-linked vasopressin receptors (V2), which mediate the antidiuretic action of the hormone. We conclude that physiologically elevated levels of AVP can downregulate vasopressin receptors in the kidney.

Water retention after oral chlorpropamide is associated with an increase in renal papillary arginine vasopressin receptors

1995 ◽  
Vol 132 (4) ◽  
pp. 459-464 ◽  
Author(s):  
J Hensen ◽  
M Haenelt ◽  
P Gross
Keyword(s):  
Arginine Vasopressin ◽  
Water Retention ◽  
Specific Activity ◽  
High Specific Activity ◽  
Plasma Osmolality ◽  
Dependent Diabetes Mellitus ◽  
Scatchard Analysis ◽  
Sprague Dawley ◽  
Water Excretion ◽  
Vasopressin Receptors

Hensen J, Haenelt M, Gross P. Water retention after oral chlorpropamide is associated with an increase in renal papillary arginine vasopressin receptors. Eur J Endocrinol 1995;132:459–64. ISSN 0804–4643 Chlorpropamide (CP), a sulfonylurea used for treatment of non-insulin dependent diabetes mellitus, is known to potentiate the antidiuretic action of arginine vasopressin (AVP), predisposing to hyponatremia. It has been suggested that CP acts directly on the antidiuretic vasopressin receptor. Detailed studies on the influence of CP on the AVP receptor, however, have been hampered by lack of a suitable radioligand. Using a newly developed radioiodinated derivative of AVP with high specific activity and high affinity for the AVP V2-receptor (125I-[8-(p-(OH)-phenylpropionyl)]-LVP), we studied the role of AVP V2-receptors in CP-induced water retention. Male-Sprague-Dawley rats were treated orally with 40 mg CP/day or placebo for 7 days, after which Scatchard analysis was performed using membranes prepared from homogenized renal papilla. After oral water load, CP-treated rats but not control rats showed a significant decrease in plasma osmolality (289 ±2.2 to 284±0.8 mosmol/kg, p < 0.05). The Kd was 0.69 ± 0.16 nmol/l in controls and 0.70 ± 0.12 nmol/l after CP treatment (NS); Bmax was 129 ± 5.3 nmol/kg protein in controls (N = 8). Chlorpropamide significantly increased receptor density (Bmax) to 167±8.4 nmol/kg protein (N = 8) (p<0.05). Plasma AVP did not change significantly during CP treatment. These data show for the first time that CP in vivo increases the density of AVP V2 receptors without altering plasma AVP. This is associated with an impairment in water excretion. Our experiments and recent reports on CP-induced inhibition of AVP binding suggest that the AVP augmentation effect of CP is related to interference of CP with the AVP V2-receptor. Johannes Hensen, Department of Medicine I, Division of Endocrinology and Metabolism, Krankenhausstr. 12, 91054 Erlangen, Germany

Characterization of Thromboxane A2/Prostaglandin H2 Receptors in Porcine Coronary Artery -The Inhibitory Effect of a Novel Dibenzoxepin Derivative, KW-3635

1992 ◽  
Vol 67 (05) ◽  
pp. 582-584 ◽  
Author(s):  
Ichiro Miki ◽  
Akio Ishii
Keyword(s):  
Coronary Artery ◽  
Binding Sites ◽  
Thromboxane A2 ◽  
Inhibitory Effect ◽  
Scatchard Analysis ◽  
Single Class ◽  
Porcine Coronary Artery ◽  
Equilibrium Binding ◽  
H2 Receptors

SummaryWe characterized the thromboxane A2/prostaglandin H2 receptors in porcine coronary artery. The binding of [3H]SQ 29,548, a thromboxane A2 antagonist, to coronary arterial membranes was saturable and displaceable. Scatchard analysis of equilibrium binding showed a single class of high affinity binding sites with a dissociation constant of 18.5 ±1.0 nM and the maximum binding of 80.7 ± 5.2 fmol/mg protein. [3H]SQ 29,548 binding was concentration-dependently inhibited by thromboxane A2 antagonists such as SQ 29,548, BM13505 and BM13177 or the thromboxane A2 agonists such as U46619 and U44069. KW-3635, a novel dibenzoxepin derivative, concentration-dependently inhibited the [3H]SQ 29,548 binding to thromboxane A2/prosta-glandin H2 receptors in coronary artery with an inhibition constant of 6.0 ± 0.69 nM (mean ± S.E.M.).

Endothelium, vasopressin receptors, and resistance to DOCA-salt hypertension

1993 ◽  
Vol 265 (1) ◽  
pp. H15-H21 ◽  
Author(s):  
C. S. Bockman ◽  
W. B. Jeffries ◽  
W. A. Pettinger ◽  
P. W. Abel
Keyword(s):  
Mesenteric Artery ◽  
Wistar Rats ◽  
Fold Increase ◽  
Vasopressin Receptor ◽  
Receptor Function ◽  
Salt Treatment ◽  
Threefold Increase ◽  
Lysine Vasopressin ◽  
Salt Hypertension ◽  
Vasopressin Receptors

Mesenteric artery rings from Wistar and Wistar-Furth rats subcutaneously treated with deoxycorticosterone acetate (DOCA) and 1% NaCl drinking water were used to measure endothelial modulation of contractile sensitivity and vasopressin receptor function and affinity. DOCA-salt hypertension reduced contractile sensitivity to arginine vasopressin (AVP) and did not affect contractile sensitivity to norepinephrine in arteries from Wistar rats. Endothelial removal caused a threefold increase in contractile sensitivity to AVP and norepinephrine in DOCA-salt hypertensive Wistar rats. In Wistar-Furth rats, DOCA-salt treatment did not affect contractile sensitivity to AVP, lysine vasopressin, oxytocin, and norepinephrine or the affinity of the vasopressin receptor for agonists or antagonists. Removal of endothelium did not affect vasopressin contractile sensitivity but caused a 15-fold increase in contractile sensitivity to norepinephrine in untreated or DOCA-salt-treated Wistar-Furth rats. These data show that reduced vasopressin receptor function and increased endothelial function that compensate for increased contractile sensitivity in arteries from DOCA-salt hypertensive Wistar rats are not the cause of resistance of DOCA-salt-treated Wistar-Furth rats to the development of enhanced contractile sensitivity and hypertension.

Epidermal growth factor accelerates renal tissue repair in a model of gentamicin nephrotoxicity in rats

1992 ◽  
Vol 263 (5) ◽  
pp. F806-F811 ◽  
Author(s):  
N. J. Morin ◽  
G. Laurent ◽  
D. Nonclercq ◽  
G. Toubeau ◽  
J. A. Heuson-Stiennon ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Renal Tissue ◽  
Sprague Dawley ◽  
Renal Tubular Cells ◽  
Sprague Dawley Rats ◽  
Epidermal Growth ◽  
Renal Tubular ◽  
Cessation Of Treatment

Epidermal growth factor (EGF) is a potent mitogen for renal tubular cells that possess specific high-affinity binding sites for this polypeptide. However, actual function of EGF within the kidney remains to be elucidated. We evaluated the effect of exogenous EGF administration on the rate of tubular regeneration in an experimental model of gentamicin (GT) nephrotoxicity. Female Sprague-Dawley rats were anesthetized, and a miniosmotic pump filled with mouse EGF or saline was implanted subcutaneously. Twenty-four hours later, GT (40 mg.kg-1 x 12 h-1 ip) was given for 4 and 8 days. Groups of treated animals and controls were killed either the day after cessation of treatment (days 5 and 9) or 4 and 8 days after the end of 8-day GT administration (days 12 and 16). Cortical GT levels of groups killed at days 5, 9, 12, and 16 were similar in animals infused with saline or EGF. Serum creatinine levels were significantly higher in GT-treated animals infused with EGF or saline and killed at days 9 and 12 compared with saline-treated animals infused with EGF or saline alone (P < 0.01). Blood urea nitrogen (BUN) also increased as a result of GT administration. However, in animals receiving GT and EGF and killed at day 16, mean BUN level was significantly lower (P < 0.01) compared with rats dosed with GT alone. In treated rats, the extent of tubular regeneration, evaluated by the rate of [3H]thymidine incorporation into renal cortical DNA or by the frequency of S-phase cells (histoautoradiography), was increased in a dose- and time-dependent fashion.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Identification and analysis of human erythropoietin receptors on a factor-dependent cell line, TF-1

Blood ◽  
1989 ◽  
Vol 73 (2) ◽  
pp. 375-380 ◽  
Author(s):  
T Kitamura ◽  
A Tojo ◽  
T Kuwaki ◽  
S Chiba ◽  
K Miyazono ◽  
...  
Keyword(s):  
Cell Line ◽  
Binding Sites ◽  
Bone Marrow Cells ◽  
Scatchard Analysis ◽  
Hematopoietic Growth Factors ◽  
Single Class ◽  
Gm Csf ◽  
Molecular Weights ◽  
Human Erythropoietin ◽  
Macrophage Colony

Abstract We have recently established a novel cell line, TF-1, from bone marrow cells of a patient with erythroleukemia, that showed an absolute growth dependency on each of three hematopoietic growth factors: erythropoietin (EPO) granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin 3 (IL-3). EPO stimulated the proliferation of TF-1 cells even at the physiologic concentration (0.03 U/mL). We performed binding experiments on TF-1 cells using radioiodinated EPO. The binding of radioiodinated EPO to TF-1 was specific, time- and temperature-dependent, and saturable. Scatchard analysis of the saturation binding data suggested the existence of a single class of binding sites (kd = 0.40 nmol/L; number of binding sites = 1,630 per cell). TF-1 cells were usually maintained in RPMI 1640 containing 10% fetal bovine serum and 5 ng/mL GM-CSF. The kd and the number of the EPO receptors were not changed by incubating the cells with IL-3, although culturing the cells in the presence of EPO resulted in down-modulation of EPO receptors. The chemical cross-linking study demonstrated that two molecules with apparent molecular weights of 105 kilodalton (Kd) and 90 Kd were the binding components of EPO. Present data suggest that human EPO receptors are very similar to the previously reported murine EPO receptors.

CORTICOSTERONE BINDING BY MOUSE SERA DURING FOETAL AND POST-NATAL DEVELOPMENT

1977 ◽  
Vol 84 (1) ◽  
pp. 177-190 ◽  
Author(s):  
Lia Savu ◽  
Emmanuel Nunez ◽  
Max-Fernand Jayle
Keyword(s):  
Amniotic Fluid ◽  
Binding Sites ◽  
Binding Proteins ◽  
Serum Proteins ◽  
Equilibrium Dialysis ◽  
Normal Adult ◽  
Scatchard Analysis ◽  
Mammalian Development ◽  
Single Class ◽  
Mean Values

ABSTRACT The binding properties of corticosterone binding globulin (CBG) of mouse sera have been studied by equilibrium dialysis and electrophoretic techniques, at different stages of foetal and post-natal development. Scatchard analysis has demonstrated in all cases a single class of high affinity saturable binding sites for corticosterone. Remarkable increases of the binding capacities were observed in the foetal and pregnant sera, as compared to normal adult and immature levels. The mean values of n1M1 × g−1 of serum proteins (concentration of binding sites, n1 × moles of binding proteins M1) were 21 10−8 in 14–19 day pregnant females, 17 10−8 in the amniotic fluid, 4.2 10−8 in 14–19 day embryos, and only 0.8 10−8 in the normal adult female. Neonatal mice, aged 0–6 days exhibited no CBG activities. The association constants showed values of 2.5–4.1 108 m−1 when measured with foetal sera, and of 1.2–2.1 108 m−1 with pregnant or control adult sera and with the amniotic fluid, at 25°C. Comparative electrophoretic, thermal denaturation and competition studies with foetal and pregnant plasma CBG's are also reported. The results are discussed in relation to the origin of CBG in the foetal serum, and also with respect to similar studies in the rat, guinea pig and man. The possible biological implications of serum steroid binding proteins in mammalian development are briefly outlined.

Involvement of estrogen receptors α and β in the regulation of cervical permeability

2000 ◽  
Vol 278 (4) ◽  
pp. C689-C696 ◽  
Author(s):  
George I. Gorodeski ◽  
Dipika Pal
Keyword(s):  
Estrogen Receptor ◽  
Binding Sites ◽  
Estrogen Receptor Α ◽  
Binding Activity ◽  
Scatchard Analysis ◽  
Single Class ◽  
Estrogen Receptor Modulators ◽  
Transcription Inhibitor ◽  
Estrogen Binding ◽  
In Cells

Estrogen increases the permeability of cultured human cervical epithelia (Gorodeski, GI. Am J Physiol Cell Physiol 275: C888–C899, 1998), and the effect is blocked by the estrogen receptor modulators ICI-182780 and tamoxifen. The objective of the study was to determine involvement of estrogen receptor(s) in mediating the effects on permeability. In cultured human cervical epithelial cells estradiol binds to high-affinity, low-capacity sites, in a specific and saturable manner. Scatchard analysis revealed a single class of binding sites with a dissociation constant of 1.3 nM and binding activity of ∼0.5 pmol/mg DNA. Estradiol increased the density of estrogen-binding sites in a time- and dose-related manner (half time ≈ 4 h, and EC50≈ 1 nM). RT-PCR assays revealed the expression of mRNA for the estrogen receptor α (αER) and estrogen receptor β (βER). Removal of estrogen from the culture medium decreased and treatment with estrogen increased the expression of αER and βER mRNA. In cells not treated with estrogen, ICI-182780 and tamoxifen increased βER mRNA. In cells treated with estrogen, neither ICI-182780 nor tamoxifen had modulated significantly the increase in αER or βER mRNA. The transcription inhibitor actinomycin D blocked the estrogen-induced increase in permeability, and it abrogated the estradiol-induced increase in estrogen binding sites. These results suggest that the estrogen-dependent increase in cervical permeability is mediated by an αER-dependent increase in transcription.

Prolonged stimulation of intrarenal V1 vasopressin receptors results in sustained hypertension

1994 ◽  
Vol 267 (5) ◽  
pp. R1217-R1225 ◽  
Author(s):  
E. Szczepanska-Sadowska ◽  
K. Stepniakowski ◽  
M. M. Skelton ◽  
A. W. Cowley
Keyword(s):  
Arterial Pressure ◽  
Intravenous Administration ◽  
Plasma Osmolality ◽  
Sprague Dawley ◽  
Sustained Hypertension ◽  
Body Sodium ◽  
Chronic Infusion ◽  
Vasopressin Receptors ◽  
Stimulation Of ◽  
Interstitial Infusion

In an earlier study, we reported that chronic intravenous administration of the V1 agonist [Phe2,Ile3,Orn8]vasopressin (V1AG) results in sustained hypertension. The present study was designed to determine whether V1-induced hypertension may be related specifically to intrarenal actions of this peptide. Chronic infusion of the V1 agonist into the medullary interstitial space of a single remaining kidney of normal, conscious Sprague-Dawley rats at the rate of 2 ng.kg-1.min-1 for 14 days resulted in a sustained rise of 18 mmHg of mean arterial pressure (MAP). After withdrawal of V1AG, MAP returned to the baseline level. During the first day of V1AG infusion, there was a net loss of body sodium and no evidence of fluid retention throughout the period of hypertension. Plasma osmolality, sodium and potassium concentration, and water intake and body weight were not significantly affected by medullary interstitial infusion of V1AG. Renal medullary interstitial infusion of an equimolar amount of arginine vasopressin (AVP) did not affect MAP. Chronic medullary interstitial infusion of the selective V1 antagonist d(CH2)5[Tyr(Me)2,Ala-NH(2)9]AVP in equimolar amounts (2.5 ng.kg-1.min-1) prevented the MAP increase elicited by intravenous V1AG. However, intravenous administration of the V1 antagonist at the same rate together with V1AG (n = 7) failed to prevent hypertension. The results indicate that hypertension can be elicited by chronic stimulation of renal medullary V1 vasopressin receptors. They also suggest that some V2 agonistic properties of AVP may restrict the hypertensive action of this hormone. The mechanism for the rise of arterial pressure remains to be determined.

Characteristics and developmental changes of corticotrophin-releasing hormone-binding sites in the fetal sheep anterior pituitary gland

1991 ◽  
Vol 130 (2) ◽  
pp. 223-229 ◽  
Author(s):  
F. Lü ◽  
K. Yang ◽  
J. R. G. Challis
Keyword(s):  
Binding Sites ◽  
Anterior Pituitary ◽  
Time Course ◽  
Scatchard Analysis ◽  
Maximum Output ◽  
Similar Time ◽  
Single Class ◽  
Fetal Sheep ◽  
Releasing Hormone ◽  
Receptor Number

ABSTRACT The responses of the fetal sheep pituitary to corticotrophin-releasing hormone (CRH) change during gestation with maximum output of ACTH around days 120–130, and decreased ACTH output near term. However, there is no information available concerning the extent to which these responses may be modulated by alterations in the number of CRH receptors. Therefore we measured specific CRH-binding sites, and changes in binding characteristics in membrane preparations from fetal sheep anterior pituitaries collected at days 65–70, 85–88, 100–110, 125–130 and at term (approximately 145 days). Binding assays were carried out using 125I-labelled Tyr-ovine CRH (125I-Tyr-oCRH), incubated with crude membrane fractions for 90 min at 22 °C. Binding was time- and temperature-dependent, linear with protein concentration, saturable and specific for oCRH. Scatchard analysis of binding data for individual tissues revealed a single class of CRH-binding sites with high affinity (Kd ≃1 nmol/l) that did not change significantly with gestational age. However, the number of CRH-binding sites increased progressively from days 65–70 to a maximum at days 125–130, then decreased at term. These results demonstrate the presence of specific CRH-binding sites in the fetal sheep anterior pituitary. Furthermore, the change in CRH receptor number with advancing pregnancy follows a similar time-course to the changes reported previously in responsiveness of the fetal sheep anterior pituitary to exogenous CRH stimulation in vivo. These results suggest that alterations in CRH receptor number may contribute to changes in responsiveness of the fetal sheep anterior pituitary to CRH during gestation. Journal of Endocrinology (1991) 130, 223–229

Characterization of vasopressin receptors of rat urinary bladder and spleen

1986 ◽  
Vol 251 (1) ◽  
pp. H115-H120 ◽  
Author(s):  
M. Thibonnier ◽  
R. M. Snajdar ◽  
J. P. Rapp
Keyword(s):  
Urinary Bladder ◽  
Cyclic Amp ◽  
Binding Sites ◽  
Binding Capacity ◽  
Specific Binding ◽  
Experimental Hypertension ◽  
Sprague Dawley ◽  
Rat Urinary Bladder ◽  
Vascular Type ◽  
Vasopressin Receptors

By use of tritiated arginine-8-vasopressin (AVP), vasopressin specific binding sites were detected on Sprague-Dawley rat urinary bladder and spleen. In both tissues, one class of high-affinity binding sites was characterized with an equilibrium dissociation constant of 1.61 +/- 0.22 and 1.91 +/- 0.16 nM and a maximal binding capacity of 155 +/- 5 and 110 +/- 11 fmol/mg of protein, for bladder and spleen, respectively. In both tissues, several experimental arguments suggest that these receptors belong to the V1-vascular type: Highly significant correlations were found between the relative agonistic vasopressor activities of eight AVP agonists and their relative abilities to inhibit [3H]AVP binding to the receptors, whereas no such relationship existed when antidiuretic activities were considered. The same profile was also observed with the antagonistic activities of five AVP antagonists. Moreover, AVP (10(-12)-10(-5) M) did not modify the basal cyclic AMP production in either tissue. As cyclic AMP is known to respond to V2 stimulation, the data suggest that the receptors measured are the V1 type. In Dahl rats the receptor characteristics were modulated by salt diet. More interestingly, the number of spleen vasopressin binding sites was always lower in Dahl salt-resistant animals than in the Dahl salt-sensitive animals receiving either a sodium deficient or a 1% NaCl or an 8% NaCl-containing diet. The exploration of vasopressin receptors regulation should facilitate the comprehension of the role played by AVP in different models of experimental hypertension.

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