INCREASED WATER PERMEABILITY OF THE BULLFROG (RANA CATESBIANA) BLADDER IN VITRO IN RESPONSE TO SYNTHETIC OXYTOCIN AND ARGININE VASOTOCIN AND TO NEUROHYPOPHYSIAL EXTRACTS FROM NONMAMMALIAN VERTEBRATES1

Endocrinology ◽  
1960 ◽  
Vol 66 (1) ◽  
pp. 112-120 ◽  
Author(s):  
WILBUR H. SAWYER
Keyword(s):  
Water Permeability ◽  
Arginine Vasotocin ◽  
Synthetic Oxytocin

The effect of arginine vasotocin on the isolated amniotic membrane of the guinea pig

1974 ◽  
Vol 52 (3) ◽  
pp. 371-386 ◽  
Author(s):  
E. Vizsolyi ◽  
A. M. Perks
Keyword(s):  
Average Rate ◽  
Individual Variability ◽  
Arginine Vasotocin ◽  
Maternal Environment ◽  
Amniotic Cavity ◽  
Net Uptake ◽  
Fetal Urine ◽  
Amniotic Membranes ◽  
Synthetic Oxytocin

Amniotic membranes from fetal guinea pigs at 0.46 of term were maintained in vitro by means of salines which reproduced the electrolytes of the natural fluids, and. which maintained small osmotic and hydrostatic gradients from the fetal to the maternal solutions. Water passed slowly from the fetal to the maternal side (average rate = 3.93 mg/cm2 per minute). Synthetic arginine vasotocin (AVT) at 8–100 vasopressor mU/ml of amniotic saline slowed the fetal–maternal flow, or reversed it to give a net uptake of water into the amniotic saline (maximum reversed flow = 10.4 mg/cm2 per minute). Despite individual variability between membranes, there was a linear relationship between the change in the rate of flow, and the log of the dose of AVT (AVT threshold indicated = 6.4 mU/ml). Synthetic arginine vasopressin (AVP) and fetal pituitary extracts produced similar responses (AVP threshold = about 1.0 mU/ml). Synthetic oxytocin was without effect in doses up to 100 oxytocic mU/ml. Although the doses tested appeared to be pharmacological, evidence is reviewed for a possible physiological significance. It is suggested that amounts of AVT, or more probably AVP, are liberated from the fetal pituitary by osmotic or other stimuli, and pass in the fetal urine into the amniotic cavity; there they act on the amnion to stimulate it to conserve or augment amniotic fluid by transporting water inwards from the maternal environment.

scholarly journals Effects of natural point mutation of rat aquaporin 5 expressed in vitro on its capacity of water permeability and membrane trafficking

2009 ◽  
Vol 56 (Supplement) ◽  
pp. 398-400 ◽  
Author(s):  
Mileva R Karabasil ◽  
Kwartarini Murdiastuti ◽  
Nunuk Purwanti ◽  
Ahmad Azlina ◽  
Purevjav Javkhlan ◽  
...  
Keyword(s):  
Point Mutation ◽  
Water Permeability ◽  
Membrane Trafficking ◽  
Aquaporin 5

Developmental changes in rabbit juxtamedullary proximal convoluted tubule water permeability

1996 ◽  
Vol 271 (4) ◽  
pp. F871-F876 ◽  
Author(s):  
R. Quigley ◽  
M. Baum
Keyword(s):  
Proximal Tubule ◽  
Water Transport ◽  
Water Permeability ◽  
Water Movement ◽  
Adult Rabbit ◽  
Osmotic Water ◽  
Glomerular Filtrate ◽  
Convoluted Tubules ◽  
Insight Into

The mammalian proximal tubule reabsorbs the bulk of the glomerular filtrate in a nearly isosmotic fashion due to the high osmotic water permeability (Pf) of this segment. Although the characteristics of proximal tubule water transport have been studied in the adult proximal tubule, little is known about the neonatal segment. The present study directly measured the Pf and diffusional water permeability (PDW) of neonatal (10 +/- 2 day old) and adult rabbit juxtamedullary proximal convoluted tubules (PCT) using in vitro microperfusion. The Pf of neonatal juxtamedullary PCT was greater than the Pf of adult juxtamedullary PCT. In contrast, the PDW was not different between the two groups. The Pf and PDW values of both neonatal and adult tubules were inhibited to the same degree by p-chloromercuribenzene sulfonate and had identical activation energies. The transepithelial reflection coefficients of NaCl and NaHCO3 were also found to be similar in both the neonatal and adult proximal tubules. Thus neonatal and adult juxtamedullary PCT have many characteristics of water transport that are identical; however, neonatal Pf is three to five times that of the adult value. This difference in Pf with identical PDW values may give an insight into the transepithelial pathway for water movement in the neonatal tubule.

scholarly journals The Vasopressin Receptor 2 Mutant R137L Linked to the Nephrogenic Syndrome of Inappropriate Antidiuresis (NSIAD) Signals through an Alternative Pathway that Increases AQP2 Membrane Targeting Independently of S256 Phosphorylation

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1354
Author(s):  
Marianna Ranieri ◽  
Maria Venneri ◽  
Tommaso Pellegrino ◽  
Mariangela Centrone ◽  
Annarita Di Mise ◽  
...  
Keyword(s):  
Water Permeability ◽  
Collecting Duct ◽  
Alternative Pathway ◽  
Water Channel ◽  
Rho Kinase ◽  
Membrane Targeting ◽  
Rock Inhibitor ◽  
Activating Mutations ◽  
Osmotic Water

NSIAD is a rare X-linked condition, caused by activating mutations in the AVPR2 gene coding for the vasopressin V2 receptor (V2R) associated with hyponatremia, despite undetectable plasma vasopressin levels. We have recently provided in vitro evidence that, compared to V2R-wt, expression of activating V2R mutations R137L, R137C and F229V cause a constitutive redistribution of the AQP2 water channel to the plasma membrane, higher basal water permeability and significantly higher basal levels of p256-AQP2 in the F229V mutant but not in R137L or R137C. In this study, V2R mutations were expressed in collecting duct principal cells and the associated signalling was dissected. V2R-R137L and R137C mutants had significantly higher basal pT269-AQP2 levels -independently of S256 and PKA-which were reduced to control by treatment with Rho kinase (ROCK) inhibitor. Interestingly, ROCK activity was found significantly higher in V2R-R137L along with activation of the Gα12/13–Rho–ROCK pathway. Of note, inhibition of ROCK reduced the basal elevated osmotic water permeability to control. To conclude, our data demonstrate for the first time that the gain-of-function mutation of the V2R, R137L causing NSIAD, signals through an alternative PKA-independent pathway that increases AQP2 membrane targeting through ROCK-induced phosphorylation at S/T269 independently of S256 of AQP2.

Release of cyclic AMP by toad urinary bladder

1975 ◽  
Vol 228 (3) ◽  
pp. 954-958 ◽  
Author(s):  
S Urakabe ◽  
JS Handler ◽  
J Orloff
Keyword(s):  
Epithelial Cells ◽  
Urinary Bladder ◽  
Cyclic Amp ◽  
Cell Membrane ◽  
Water Permeability ◽  
Ringer Solution ◽  
Mucosal Surface ◽  
Toad Urinary Bladder ◽  
Solution Bathing

Cyclic AMP accumulates in the Ringer solution bathing the toad urinary bladder in vitro. At least 4 times more cyclic AMP is released into the solution bathing the serosal surface than into the solution bathing the mucosal surface. Most of the cyclic AMP originates in the epithelial cells rather than the stroma. Vasopressin increased the content of cyclic AMP in the epithelial cells and increases the amount of cyclic AMP in the Ringer solution. Since there is not an increase in medium cyclic AMP when cell cyclic AMP levels are increased by theophylline, it is suggested that theophylline may reduce the permeability of the cell membrane to cyclic AMP. Finally, it is demonstrated that 10 mM NaF increase the amount of cyclic AMP in the epithelial cells and in the solution bathing the bladder, but block the effect of vasopressin on water permeability, presumably at a step subsequent to the formation of cyclic AMP.

Responses of nerve-free vessels to vasoactive amines and polypeptides

1965 ◽  
Vol 208 (4) ◽  
pp. 748-753 ◽  
Author(s):  
Avril V. Somlyo ◽  
Chi-Yuan Woo ◽  
Andrew P. Somlyo
Keyword(s):  
Umbilical Artery ◽  
Main Pulmonary Artery ◽  
Umbilical Vessels ◽  
Vasoconstrictor Response ◽  
Human Umbilical Artery ◽  
Vasoconstrictor Effect ◽  
Rhythmic Contractions ◽  
Synthetic Oxytocin ◽  
Indirect Action

Contractile responses of helically cut strips of noninnervated human umbilical artery and vein were determined. Spontaneous, rhythmic contractions were exhibited by both preparations, but were greater in magnitude and duration in umbilical veins. Vasoconstriction elicited by sympathomimetic amines was variable, and generally of a low order. The response to norepinephrine was not potentiated by cocaine (10 µg/ml) but was blocked by Dibenamine (1.0–1.5 µg/ml). Umbilical vasoconstrictor response to tyramine (1.0–10.0 µg/ml) indicated the direct vasoconstrictor effect of this agent. The similar norepinephrine-to-tyramine sensitivity ratios of umbilical vessels and canine main pulmonary artery were interpreted as evidence against the indirect action of tyramine in vitro. Isoproterenol produced no vasodilation in umbilical vessels, suggesting the absence of ß-adrenergic pathways. Oxytocin (>>0.1 mU/ml) was a highly effective umbilical vasoconstrictor. Native and synthetic oxytocin preparations were equiactive and produced tachyphylaxis to each other. Native and synthetic lysine-8-vasopressin (>>0.005 U/ml) and angiotensin amide (>>0.002 µg/ml) produced only minimal and inconsistent vasoconstriction, while serotonin (>>0.004 µg/ml) was as effective as oxytocin.

Water transport in collecting ducts of Japanese quail

1996 ◽  
Vol 271 (6) ◽  
pp. R1535-R1543 ◽  
Author(s):  
H. Nishimura ◽  
C. Koseki ◽  
T. B. Patel
Keyword(s):  
Japanese Quail ◽  
Water Permeability ◽  
Water Movement ◽  
Collecting Duct ◽  
Urine Concentration ◽  
Arginine Vasotocin ◽  
Minor Effect ◽  
Thick Ascending Limb ◽  
Cortical Collecting Duct ◽  
Dark Cells

Previously, we reported that the countercurrent urine concentration mechanism in birds appears to operate by recycling of a single solute (NaCl), in which the thick ascending limb of looped nephrons provides an energy source. To determine the importance of the medullary collecting duct (MCD) in the countercurrent multiplier system, we examined in isolated and perfused MCDs from Japanese quail, Coturnix coturnix, the osmotic and/or diffusional water permeability and whether arginine vasotocin (AVT) regulates water permeability. We noted that dark cells that possess electron-dense cytoplasm and numerous mitochondria and light mucus-secreting cells exist in the cortical collecting duct (CD), whereas only mucus-secreting cells are present in the MCDs. The volume flux (Jv) in the MCDs from intact birds and that from the water-deprived birds were nearly zero; after exposure to a hyperosmotic bath and AVT (2 x 10(-5) M), the Jv was significantly higher in water-deprived birds. The diffusional water permeability (Pdw) was moderately high in MCDs bathed in an isosmotic bath in which the Pdw was increased slightly by AVT (10(-5) M, bath) and more markedly (10(-5) M) by forskolin (Fsk), whereas 1,9-dideoxy Fsk (an inactive analogue) showed no effect. Furthermore, the basal adenosine 3',5'-cyclic monophosphate (cAMP) levels were higher in the medulla than in the cortex and were stimulated only slightly by AVT (10(-5) M) and markedly by Fsk (10(-4) M) in both the cortex and medulla. These results in the C. coturnix CD indicate the following. 1) Two types of cells are present; whereas dark cells resemble mammalian intercalated cells morphologically, it is not certain whether mucus-secreting cells are equivalent to principal cells. 2) AVT increases Pdw via a cAMP mechanism; the relatively high basal Pdw and minor effect of AVT on Jv and Pdw suggest, however, that diffusional water movement across the MCD may occur without significant direct control by AVT.

Effect of calcitonin on urine concentration in the rat

1983 ◽  
Vol 244 (4) ◽  
pp. F432-F435 ◽  
Author(s):  
S. Carney ◽  
T. Morgan ◽  
C. Ray ◽  
L. Thompson
Keyword(s):  
Water Permeability ◽  
Partial Agonist ◽  
Collecting Duct ◽  
Free Water ◽  
Urine Concentration ◽  
Distal Nephron ◽  
Free Water Clearance ◽  
Normal Increase

Because mammalian distal nephron segments with both calcitonin- and antidiuretic hormone- (ADH) sensitive adenylate cyclase activity have been described, in vivo and in vitro experiments were performed to study the effect of calcitonin on rat distal nephron water permeability. Calcitonin 1 and 0.1 U/ml, but not 0.01 U/ml, significantly increased the diffusional water permeability in the isolated papillary collecting duct by 15 and 11%, respectively. However, this effect was small when compared with a 68% increase with a supramaximal concentration of ADH (from 4.0 +/- 0.3 to 6.7 +/- 0.9 microns/s; n = 6, P less than 0.01). The normal increase in water permeability with increasing concentration of ADH (0.02 and 0.2 mU/ml) was depressed by the previous addition of calcitonin (1 U/ml) to the bath but was unaltered with the supramaximal ADH concentration (2 mU/ml). Verapamil, a compound that antagonizes cellular calcium entry, did not alter the effect of calcitonin on diffusional water permeability. Calcitonin in concentrations of 0.05, 0.5, and 5 U/ml produced a significant reduction in urine flow and free water clearance. Pretreatment with calcitonin in these concentrations inhibited the antidiuretic action of ADH. These studies suggest that calcitonin acts as a partial agonist to ADH within the distal nephron. It is unclear whether such an action represents a physiological or a pharmacological effect.

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