Renal histamine H1 and H2 receptors: characterization and functional significance

1978 ◽  
Vol 235 (6) ◽  
pp. F570-F575
Author(s):  
R. O. Banks ◽  
J. D. Fondacaro ◽  
M. M. Schwaiger ◽  
E. D. Jacobson
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Renal Vasculature ◽  
H2 Antagonist ◽  
H2 Receptors ◽  
Chloride Excretion ◽  
Intrarenal Blood Flow ◽  
Histamine H2 Antagonist ◽  
H1 Antagonist ◽  
Sustained Increase

Canine experiments were designed to determine if both histamine H1 and H2 receptors are present in the renal circulation. Renal blood flow (RBF) increased steeply over the first minute of intra-arterial histamine infusion, then increased gradually to a plateau in 3– –5 min. Infusion of either histamine + H2 antagonist or of H1 agonist produced the initial rapid increase in RBF, whereas infusion of either histamine + H1 antagonist or of H2 antagonist produced a slower but more sustained increase in RBF. Histamine significantly increased urine flow rate (V), chloride excretion, and glomerular filtration rate (GFR). Infusion of the H2 agonist also increased V and Cl excretion without affecting GFR. By contrast H1 agonist significantly reduced V and Cl excretion and tended to reduce GFR (P less than 0.1 greater than 0.05). Histamine, H1 agonist, and H2 agonist each increased inner cortical more than outer cortical blood flow. These data suggest that 1) H1 and H2 receptors are present in the renal vasculature, 2) changes in intrarenal blood flow distribution are not responsible for histamine-induced diuresis, and 3) H1 receptors are primarily postglomerular while H2 receptors exhibit both pre- and postglomerular distribution.

Intrarenal blood flow distribution in the desert quail following salt loading

1976 ◽  
Vol 231 (4) ◽  
pp. 1111-1118 ◽  
Author(s):  
EJ Braun
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Renal Vasculature ◽  
Salt Loading ◽  
Small Surface ◽  
Intrarenal Blood Flow ◽  
Afferent Arterioles ◽  
Renal Microvasculature ◽  
Made In

The total-kidney glomerular filtration rate (GFR) falls when birds are salt loaded. This fall in GFR is caused by glomerular intermittency. The nephrons that stop filtering are small, surface nephrons without loops of Henle. Larger nephrons with loops of Henle in the deeper regions of the kidney continue to filter during salt loading. Microfil casts were made of the renal microvasculature of the desert quail, Lophortyx gambelii, in an attempt to determine at what points intrarenal blood flow is regulated to cause glomerular intermittency. Casts of the renal vasculature were made in quail that were hydrated and in quail that were salt loaded. The results indicate that the small, surface nephrons stop filtering during salt loading because of a vasoconstriction at the level of the afferent arterioles of these nephrons. At the same time, blood flow is maintained to the large nephrons with loops of Henle. Reducing GFR at the expenses of excreting wastes can be viewed as a mechanism to conserve body water during periods of water deprivation.

Measurement of Intrarenal Blood-Flow Distribution in the Rabbit Using Radioactive Microspheres

1975 ◽  
Vol 48 (1) ◽  
pp. 51-60 ◽  
Author(s):  
D. J. Warren ◽  
J. G. G. Ledingham
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Cortex ◽  
Flow Distribution ◽  
Rabbit Kidney ◽  
Radioactive Microspheres ◽  
Injection Dose ◽  
Intrarenal Blood Flow ◽  
Total Renal Blood Flow

1. Total renal blood flow and its distribution within the renal cortex of the conscious rabbit were studied with radioactive microspheres of 15 and 25 μm diameter. 2. The reliability of the microsphere technique was influenced by microsphere diameter and number (dose). The optimum microsphere diameter for determination of flow distribution in the rabbit kidney was 15 μm and dose 100–150 000 spheres. 3. Spheres of 15 μm nominal diameter were randomly distributed within the renal cortex of adult rabbits. The larger spheres in batches nominally 15 μm in diameter in young rabbits and 25 μm diameter in adult rabbits were preferentially distributed to the superficial cortex. 4. In adult rabbits 15 μm diameter spheres lodged in glomerular capillaries. Larger spheres occasionally lodged in interlobular arteries causing intrarenal haemorrhage. 5. Microspheres of 15 μm caused a decrease in renal clearance of creatinine and of p-aminohippurate when the total injection dose was about 200 000 spheres. These effects were greater when the injection dose was increased to 500 000 spheres. 6. The reduction in total renal blood flow observed with large doses of spheres largely reflected decreased outer cortical flow, as measured by a second injection of spheres, and confirmed by a decrease in p-aminohippurate extraction. 7. The reproducibility of multiple injection studies was limited by these intrarenal effects of microspheres. 8. Total renal blood flow measured in six rabbits in acute experiments by the microsphere technique was 107 ± 12 (mean±sd) ml/min and by p-aminohippurate clearance was 100 ± 10 ml/min. 9. Total renal blood flow in twelve conscious, chronically instrumented rabbits was 125 ± 11 ml/min, of which 92 ± 6 ml/min was distributed to the superficial cortex and 33 ± 4 ml/min to the deep cortex.

The Effect of Furosemide on the Intrarenal Blood Flow Distribution in the Dog

1972 ◽  
Vol 50 (8) ◽  
pp. 774-783 ◽  
Author(s):  
Serge Carrière ◽  
Michel Desrosiers ◽  
Jacques Friborg ◽  
Michèle Gagnan Brunette
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Urine Volume ◽  
Flow Distribution ◽  
Blood Flow Rate ◽  
Initial Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow ◽  
Femoral Blood ◽  
Furosemide Administration

Furosemide (40 μg/min) was perfused directly into the renal artery of dogs in whom the femoral blood pressure was reduced (80 mm Hg) by aortic clamping above the renal arteries. This maneuver, which does not influence the intrarenal blood flow distribution, produced significant decreases of the urine volume, natriuresis, Ccreat, and CPAH, and prevented the marked diuresis normally produced by furosemide. Therefore the chances that systemic physiological changes occurred, secondary to large fluid movements, were minimized. In those conditions, however, furosemide produced a significant increase of the urine output and sodium excretion in the experimental kidney whereas Ccreat and CPAH were not affected. The outer cortical blood flow rate (ml/100 g-min) was modified neither by aortic constriction (562 ± 68 versus 569 ± 83) nor by the subsequent administration of furosemide (424 ± 70). The blood flow rate of the outer medulla in these three conditions remained unchanged (147 ± 52 versus 171 ± 44 versus 159 ± 54). The initial distribution of the radioactivity in each compartment remained comparable in the three conditions. In parallel with the results from the krypton-85 disappearance curves, the autoradiograms, silicone rubber casts, and EPAH did not suggest any change in the renal blood flow distribution secondary to furosemide administration.

Measurement of Intrarenal Blood Flow Distribution

1978 ◽  
pp. 41-74 ◽  
Author(s):  
Norbert H. Lameire ◽  
Elaine L. Chuang ◽  
Richard W. Osgood ◽  
Jay H. Stein
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow

scholarly journals Intrarenal Blood Flow Distribution (IRBF) in the Puppy Using Xenon Washout and Microspheres

1970 ◽  
Vol 4 (5) ◽  
pp. 446-446
Author(s):  
Pedro A Jose ◽  
Alexander G Logan ◽  
Gilbert M Eisner ◽  
Lawrence M Slotkoff ◽  
Charles E Hollerman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow ◽  
Xenon Washout

Intrarenal blood flow distribution in dog kidney determined by 99mTc microaggregates and 201Tl

1988 ◽  
Vol 255 (6) ◽  
pp. H1535-H1541 ◽  
Author(s):  
U. Abildgaard ◽  
O. Amtorp ◽  
J. Gyring ◽  
G. Daugaard ◽  
B. Larsen
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Rate ◽  
Blood Flow Distribution ◽  
Local Blood Flow ◽  
Single Experiment ◽  
Cortical Zone ◽  
Dog Kidney ◽  
Intrarenal Blood Flow ◽  
Intrarenal Distribution

Intrarenal distribution of blood flow was assessed with radioactive albumin microaggregates (MA) in three cortical zones of the dog kidney. The experimentally obtained zonal fractions of total renal blood flow were compared with predicted zonal blood flow fractions obtained in a mathematical model. The maximal degree of skimming that could possibly occur in a single experiment was estimated. The analysis showed that local blood flow in the inner cortical zone was maximally underestimated by 17% because of skimming of MA, and in the outer cortical zone the blood flow was maximally overestimated by 13% with the method of radioactive MA uptake. Renal uptake of 201Tl was measured simultaneously in exactly the same locations. Paired measurements of intrarenal blood flow distribution by MA and Tl uptake methodologies showed that local blood flow assessed with MA in the inner cortical zone was significantly lower than that obtained with 201Tl and that a higher blood flow rate was obtained in the outer cortical zone with MA compared with 201Tl. This disparity could be accounted for by the effect of skimming of MA as predicted by the model.

Skimming of microspheres in vitro: implications for measurement of intrarenal blood flow

1981 ◽  
Vol 241 (3) ◽  
pp. H342-H347 ◽  
Author(s):  
E. S. Ofjord ◽  
G. Clausen ◽  
K. Aukland
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Particle Inertia ◽  
Local Flow ◽  
Size Dependent ◽  
Dog Kidney ◽  
Intrarenal Blood Flow ◽  
Renal Cortical Blood Flow

Skimming could result in erroneous estimation of renal cortical blood flow distribution as measured by microspheres. Skimming of microspheres with diameters 10, 12, and 15 micrometers and red blood cells was therefore studied in a model in which an interlobular artery and its first arteriolar branch were simulated by 80- and 30-micrometers-wide slits between glass prisms. The experiments were performed with citrated blood at a hematocrit (Hct) of 40, flow velocities of 3 and 6 cm/s, and branch flow varying from 2 to 25%. At a branch flow fraction comparable to that of a deep arteriole in the dog kidney (3%), Hct in branch blood was 24% lower than that of input blood, whereas 10-, 12-, and 15-micrometers microsphere concentrations were 75, 81, and 87% lower, respectively. The size-dependent skimming was probably caused by wall exclusion in the main channel. Differences in particle inertia did not affect skimming. The results suggest that the disparate local flow values obtained by use of microspheres of different sizes in dog and rat kidneys are due to a size-dependent skimming of the microspheres.

Histamine receptor in bullfrog gastric mucosa

1981 ◽  
Vol 241 (2) ◽  
pp. G93-G97
Author(s):  
S. J. Hersey
Keyword(s):  
Gastric Mucosa ◽  
Histamine Receptor ◽  
Histamine Receptors ◽  
Histamine Antagonists ◽  
Competitive Antagonism ◽  
H2 Antagonist ◽  
H2 Receptors ◽  
High Concentrations ◽  
H1 Antagonist ◽  
Very High

The histamine receptor of isolated bullfrog gastric mucosa was characterized in terms of respiration and acid secretory responses to histamine antagonists and agonists. Cimetidine, a selective H2-antagonist, showed competitive antagonism of histamine responses with a pA2 value of 6.55. In contrast, the H1-antagonist, mepyramine, showed inhibition only at very high concentrations. Based on these results, the histamine receptor would be classified as the H2 type. Measurements of agonist potency sequence revealed a marked difference between the amphibian and mammalian gastric histamine receptors. The selective H1-agonists, 2-pyridylethylamine and 2-aminoethylthiozol, were found to be more efficacious than the selective H2-agonists, dimaprit and impromidine. The lack of efficacy for dimaprit and impromidine does not appear to be due to a lack of binding to the receptor because these agents inhibit responses to histamine. For dimaprit, the inhibition was found to be competitive with an apparent pA2 value of 5.37. These results indicate that there is a molecular difference between H2-receptors in mammals versus amphibians.

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