INACTIVATION OF ARGININE- AND LYSINE-VASOPRESSIN BY SLICES FROM DIFFERENT ZONES OF THE RAT KIDNEY AND BY RAT LIVER SLICES

1963 ◽  
Vol 44 (4) ◽  
pp. 545-562 ◽  
Author(s):  
N. A. Thorn ◽  
N. B. S. Willumsen
Keyword(s):  
Antidiuretic Hormone ◽  
Rat Kidney ◽  
Extracellular Fluid ◽  
Outer Cortex ◽  
Liver Slices ◽  
Lysine Vasopressin ◽  
Site Of Action ◽  
The Difference ◽  
High Concentrations ◽  
Inner Cortex

ABSTRACT A method was developed for studying the inactivation of antidiuretic hormone in slices from different zones of the rat kidney. The essential features of the method are: The use of thin slices from 4 zones: outer cortex, inner cortex, outer medulla and papilla which are incubated aerobically with the hormone in a medium that has a composition essentially the same as rat extracellular fluid, including a calcium concentration of 2.5 mmol. The inactivation of arginine- and lysine-vasopressin by these slices at 25° C and 37° C for 2 hours was studied. All zones inactivated both vasopressins, but the most marked inactivation activity per mg dry tissue was found in the papillary zone. High concentrations of sodium chloride in the incubation medium did not affect the inactivation of vasopressin by papillary slices. The amounts of arginine- and lysine-vasopressin (expressed in rat pressor units) which were inactivated per mg dry tissue in the different zones during the incubation period were equivalent. Similar results were found in experiments on the inactivation of the two hormones by liver slices. These findings are discussed in relation to the problems of the site of action of antidiuretic hormone and the difference in the antidiuretic response to arginine- and lysine-vasopressin which is found after i. v. injection in the rat.

Distribution of immunoreactive kallikrein along the rat nephron

1983 ◽  
Vol 244 (5) ◽  
pp. F510-F515 ◽  
Author(s):  
D. Proud ◽  
M. A. Knepper ◽  
J. J. Pisano
Keyword(s):  
Rat Kidney ◽  
Outer Cortex ◽  
Kinin System ◽  
Nephron Segments ◽  
Collecting Ducts ◽  
Site Of Action ◽  
Collecting Tubules ◽  
A Site ◽  
Kallikrein Kinin System ◽  
Convoluted Tubules

We have used a direct radioimmunoassay to localize kallikrein along the corticomedullary axis of the rat kidney and in microdissected rat cortical nephron segments. As previously seen in rat and dog, kallikrein content was highest in the outer cortex and decreased progressively toward the papillary tip. In microdissected cortical nephron segments, the highest kallikrein content was found in the connecting tubule [176 +/- 16 (SE) pg/mm tubule length (n = 12)]. In addition, a significant amount of kallikrein was found in distal convoluted tubules [53 +/- 4 pg/mm (n = 14)], initial collecting tubules [75 +/- 10 pg/mm (n = 14)], and cortical collecting ducts [37 +/- 4 pg/mm (n = 13)]. Little or no kallikrein was found in glomeruli, proximal convoluted tubules, proximal straight tubules, and cortical thick ascending limbs. These results are compatible with a site of action of the kallikrein-kinin system in the cortical segments of the rat distal nephron.

Circulating Inhibitor of Sodium—Potassium-Activated Adenosine Triphosphatase after Expansion of Extracellular Fluid Volume in Rats

1977 ◽  
Vol 53 (4) ◽  
pp. 329-334 ◽  
Author(s):  
H. C. Gonick ◽  
H. J. Kramer ◽  
W. Paul ◽  
E. Lu
Keyword(s):  
Inhibitory Activity ◽  
Adenosine Triphosphatase ◽  
Rat Kidney ◽  
Gel Filtration ◽  
Extracellular Fluid ◽  
Weight Fraction ◽  
Sodium Potassium ◽  
Lysine Vasopressin ◽  
Control Serum ◽  
Isotonic Sodium Chloride

1. Serum was collected from normal rats and from rats volume-expanded with isotonic sodium chloride solution. 2. The serum was fractionated by gel filtration on Sephadex G-25 and each fraction was tested for inhibitory activity against sodium—potassium-activated adenosine triphosphatase prepared from rat kidney homogenate. 3. A single low-molecular-weight fraction, eluting after the salts and after exogenously added lysine-vasopressin, had significantly greater enzyme inhibitory activity when obtained from serum of volume-expanded animals than from control serum. 4. As this fraction has been shown in previous independent studies to contain a natriuretic factor, it may be concluded that one property of this factor is the ability to inhibit sodium—potassium-activated adenosine triphosphatase.

scholarly journals NEW OBSERVATIONS ON DISCREPANCIES IN THE HISTOCHEMICAL LOCALIZATION OF LEUCINE AMINOPEPTIDASE

1962 ◽  
Vol 10 (3) ◽  
pp. 315-323 ◽  
Author(s):  
MARVIN M. NACHLAS ◽  
MELVIN M. FRIEDMAN ◽  
ARNOLD M. SELIGMAN
Keyword(s):  
Leucine Aminopeptidase ◽  
Rat Kidney ◽  
Histochemical Demonstration ◽  
Test Tube ◽  
Aminopeptidase Activity ◽  
Diazonium Salts ◽  
Outer Cortex ◽  
Fast Blue ◽  
Ph Buffer ◽  
Inner Cortex

Differences in the localization of leucine aminopeptidase in the cortex of the rat kidney have been reported with two methods employing the same substrate. Test tube and tissue experiments were carried out in an effort to explain the disparity. Substrate concentration, pH, buffer, the use of an activator, duration of incubation and temperature of incubation were found to have insignificant effects. Four important findings were (1) leucine aminopeptidase activity of the inner cortex of the rat kidney assayed two to three times greater than that of the outer cortex, (2) this difference was confirmed by histochemical demonstration with both methods, (3) fast blue B inhibited the enzyme more than fast garnet GBC and fast Corinth V, and (4) fast blue B coupled faster than the other diazonium salts.

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

scholarly journals Thunderstorm outflows preceding epidemics of asthma during spring and summer

Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 468-471
Author(s):  
G B Marks ◽  
J R Colquhoun ◽  
S T Girgis ◽  
M Hjelmroos Koski ◽  
A B A Treloar ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Ground Level ◽  
Fold Increase ◽  
Underlying Mechanism ◽  
Detailed Examination ◽  
Asthma Exacerbations ◽  
Eastern Australia ◽  
The Difference ◽  
High Concentrations ◽  
Thunderstorm Outflow

BACKGROUNDA study was undertaken to assess the importance of thunderstorms as a cause of epidemics of asthma exacerbations and to investigate the underlying mechanism.METHODSA case control study was performed in six towns in south eastern Australia. Epidemic case days (n = 48) and a random sample of control days (n = 191) were identified by reference to the difference between the observed and expected number of emergency department attendances for asthma. The occurrence of thunderstorms, their associated outflows and cold fronts were ascertained, blind to case status, for each of these days. In addition, the relation of hourly pollen counts to automatic weather station data was examined in detail for the period around one severe epidemic of asthma exacerbations. The main outcome measure was the number of epidemics of asthma exacerbations.RESULTSThunderstorm outflows were detected on 33% of epidemic days and only 3% of control days (odds ratio 15.0, 95% confidence interval 6.0 to 37.6). The association was strongest in late spring and summer. Detailed examination of one severe epidemic showed that its onset coincided with the arrival of the thunderstorm outflow and a 4–12 fold increase in the ambient concentration of grass pollen grains.CONCLUSIONSThese findings are consistent with the hypothesis that some epidemics of exacerbations of asthma are caused by high concentrations of allergenic particles produced by an outflow of colder air, associated with the downdraught from a thunderstorm, sweeping up pollen grains and particles and then concentrating them in a shallow band of air at ground level. This is a common cause of exacerbations of asthma during the pollen season.

UT-B1 proteins in rat: tissue distribution and regulation by antidiuretic hormone in kidney

2002 ◽  
Vol 283 (5) ◽  
pp. F912-F922 ◽  
Author(s):  
M.-M. Trinh-Trang-Tan ◽  
F. Lasbennes ◽  
P . Gane ◽  
N. Roudier ◽  
P. Ripoche ◽  
...  
Keyword(s):  
Antidiuretic Hormone ◽  
Brain Cortex ◽  
Rat Kidney ◽  
Cross Reactivity ◽  
Ependymal Cells ◽  
Kidney Medulla ◽  
Vasa Recta ◽  
Cell Processes ◽  
Rat Tissue

UT-B1 is the facilitated urea transporter of red blood cells (RBCs) and endothelial cells of descending vasa recta in the kidney. Immunoblotting with a polyclonal antibody against the C-ter sequence of rat UT-B1 revealed UT-B1 as both nonglycosylated (29 kDa) and N-glycosylated (47.5 and 33 kDa) proteins in RBC membranes, kidney medulla, brain, and bladder in rat. In testis, UT-B1 was expressed only as a nonglycosylated protein of 47.5 kDa. Immunocytochemistry confirmed that the location of UT-B1 is restricted to descending vasa recta. In brain, UT-B1 protein was found in astrocytes and ependymal cells. Cell bodies and perivascular end feet of astrocytes were labeled in brain cortex, whereas astrocyte cell processes were labeled in corpus callosum. Flow cytometry analysis of RBCs revealed a good cross-reactivity of the antibody with mouse and human UT-B1. UT-B1 protein expression in rat kidney medulla was downregulated greatly by long-term [deamino-Cys1,d-Arg8]vasopressin infusion and moderately by furosemide treatment. This study discloses an uneven distribution of UT-B1 protein within astrocytes and the regulation of renal UT-B1 protein by antidiuretic hormone.

Cholesterol Metabolism and Vitamin B6. III. The Stimulation of Hepatic Cholesterogenesis in the Vitamin B6-Deficient Rat

1971 ◽  
Vol 49 (8) ◽  
pp. 933-935 ◽  
Author(s):  
C. M. Hinse ◽  
P. J. Lupien
Keyword(s):  
Vitamin B6 ◽  
Cholesterol Metabolism ◽  
Krebs Cycle ◽  
Pool Size ◽  
Liver Slices ◽  
Liver Homogenates ◽  
The Difference ◽  
Hepatic Cholesterogenesis ◽  
Stimulation Of

The rate of incorporation of labeled acetate into cholesterol by liver slices of pyridoxine-deficient rats was found to be three times that of control rats; with liver homogenates the difference between the two groups was even greater. Using the CO2 trapping technique, a 30% decrease in the hepatic acetate pool size was observed in pyridoxine-deficient rats and a 20% increase in pair-fed rats. Activity of the Krebs cycle was decreased by a third in the pair-fed rats.

Comparative analysis of the ontogeny of a sodium-dependent bile acid transporter in rat kidney and ileum

1996 ◽  
Vol 271 (2) ◽  
pp. G377-G385 ◽  
Author(s):  
D. M. Christie ◽  
P. A. Dawson ◽  
S. Thevananther ◽  
B. L. Shneider
Keyword(s):  
Bile Acid ◽  
Rat Kidney ◽  
Membrane Vesicles ◽  
Mrna Levels ◽  
Sodium Dependent ◽  
Bile Acid Transporter ◽  
Old Rats ◽  
Acid Transporter ◽  
The Difference ◽  
And Function

An apical sodium-dependent bile acid transporter (ASBT) has recently been cloned and characterized in the rat ileum. Northern and Western blotting revealed both the ASBT mRNA and protein in rat kidney. The coding sequence of the kidney transcript was found to be identical to the previously cloned ileal ASBT. Indirect immunofluorescence studies localized the ASBT protein to the apical membrane of the renal proximal convoluted tubule. Kinetic analysis of sodium-dependent taurocholate uptake using membrane vesicles revealed a similar Michaelis-Menten constant value for taurocholate in the kidney and intestine. ASBT protein and function were present in the kidney but not the ileum from 7-day-old rats. On postnatal day 7, there was a sevenfold increase in ASBT steady-state mRNA levels in the kidney relative to the ileum, yet nuclear run-on assays revealed that the nascent transcription rates at this age were virtually the same. This suggests that the difference in the neonatal expression of the ASBT gene in the kidney and ileum may be in part due to differences in mRNA stability.

Ca-dependent hemodynamic and natriuretic effects of atrial extract in isolated rat kidney

1984 ◽  
Vol 246 (4) ◽  
pp. F447-F456 ◽  
Author(s):  
M. J. Camargo ◽  
H. D. Kleinert ◽  
S. A. Atlas ◽  
J. E. Sealey ◽  
J. H. Laragh ◽  
...  
Keyword(s):  
Perfusion Pressure ◽  
Rat Kidney ◽  
Fractional Excretion ◽  
Electrolyte Excretion ◽  
Renal Vasculature ◽  
Filtration Fraction ◽  
Perfused Rat Kidney ◽  
Site Of Action ◽  
Initial Control ◽  
Renal Vascular

The effects of rat atrial tissue extract on renal hemodynamics and fluid and electrolyte excretion were investigated in the isolated perfused rat kidney (IK). IK were perfused at a constant effective perfusion pressure of about 90 mmHg. After control clearance periods (C), extracts of rat atria (AE) or ventricles (VE) were added to the perfusate and three 10-min experimental periods followed. AE, but not VE, significantly increased (P less than 0.001) renal vascular resistance (RVR) to 133 +/- 8% of C, GFR to 201 +/- 34%, filtration fraction to 245 +/- 41%, urine flow (V) to 675 +/- 131%, fractional excretion (FE) of H2O to 336 +/- 29%, absolute Na excretion (UNaV) to 1,259 +/- 290%, FENa to 642 +/- 129%, UKV to 2,226 +/- 1,237%, and FEK to 542 +/- 119%. Despite the marked natriuresis, since GFR doubled, Na reabsorption rose from 78.3 +/- 36.3 in C to 132 +/- 36.3 mueq/min after AE. The effects of AE were immediate and lasted to the end of the perfusion. The lower the initial control GFR, the larger was the AE-induced increase in GFR. Perfusion with low [Ca] (0.2 mM) or verapamil (10(-5) M) severely blunted the hemodynamic, diuretic, kaliuretic, and natriuretic effects of AE. AE decreased rather than increased the RVR when IK were perfused with vasoconstrictors such as angiotensin II, norepinephrine, or vasopressin. The results demonstrate that AE acts directly on the kidney, eliciting powerful Ca-dependent hemodynamic and natriuretic responses. The natriuresis induced by AE can be accounted for, at least in part, by its renal hemodynamic effects rather than by the presence of a putative tubular natriuretic factor. The hypothesis is advanced that AE contains a substance(s) which behaves as a functional agonist/antagonist of endogenous vasoconstrictors with a preferential site of action on the efferent arterioles of the renal vasculature.

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