Localization of Acidification of Urine, Potassium and Ammonia Secretion and Phosphate Reabsorption in the Nephron of the Dog

1958 ◽  
Vol 194 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Robert F. Pitts ◽  
Ruth S. Gurd ◽  
Richard H. Kessler ◽  
Klaus Hierholzer
Keyword(s):  
Distal Part ◽  
Potassium Phosphate ◽  
Proximal Part ◽  
Ammonium Ion ◽  
Sodium Reabsorption ◽  
Hydrogen Ions ◽  
Acid Urine ◽  
Urine Potassium ◽  
A Site ◽  
Stop Flow

The Malvin, Sullivan and Wilde ( The Physiologist 1: 58, 1957) stop flow technique for the localization of tubular function has been applied to a study of potassium and acid excretion in the dog. It has been observed that the urine is acidified in the distal part of the nephron at a site of avid sodium reabsorption. Potassium and ammonia are secreted in the same portion of the tubule. Diamox reduces acidification of the urine and secretion of ammonia and enhances the secretion of potassium. Phosphate is reabsorbed in the proximal part of the nephron in a region which is coextensive with that which secretes p-aminohippurate. All our data are consonant with the view that a mechanism located in the distal part of the nephron exchanges cellular hydrogen and/or potassium ions for sodium ions in the tubular urine. Ammonia diffuses into acid urine and is trapped as ammonium ion. Diamox, by interfering with the supply of cellular hydrogen ions, reduces exchange of hydrogen for sodium and favors the exchange of potassium for sodium.

Renal transport sites for K, H and NH3. Effect of impermeant anions on their transport

1960 ◽  
Vol 198 (2) ◽  
pp. 244-254 ◽  
Author(s):  
Lawrence P. Sullivan ◽  
Walter S. Wilde ◽  
Richard L. Malvin
Keyword(s):  
Negative Charge ◽  
Distal Tubule ◽  
Sodium Reabsorption ◽  
Renal Transport ◽  
Transport Mechanisms ◽  
Collecting Ducts ◽  
Tubular Lumen ◽  
Potassium Hydrogen ◽  
A Site ◽  
Stop Flow

The stop flow technique was used to locate the sites of the renal transport mechanisms for potassium, hydrogen and ammonium. Data were obtained which indicate that these cations are secreted in a very distal area of the nephron, presumably in the collecting ducts. Potassium reabsorption also occurs in a distal area immediately proximal to the secretory site. Infusions of thiosulfate, ferrocyanide and phosphate alter the stop flow concentration patterns so that secretion of the cations appears to take place throughout the distal tubule and to be coextensive with distal sodium reabsorption. No clear indication of potassium reabsorption is evident under these circumstances. It is suggested that these anions, because of the impermeability of the distal tubule to them and because of their negative charge, attract hydrogen and potassium into the tubular lumen as sodium is reabsorbed. In effect, an abnormal exchange mechanism is created at a site proximal to that where active secretion of hydrogen and potassium occurs.

scholarly journals Stratigraphic revision and reconstruction of the deep-sea fan of the Voirons Flysch (Voirons Nappe, Chablais Prealps)

2021 ◽  
Vol 114 (1) ◽  
Author(s):  
Jérémy Ragusa ◽  
Lina Maria Ospina-Ostios ◽  
Pascal Kindler ◽  
Mario Sartori
Keyword(s):  
Deep Sea ◽  
Distal Part ◽  
Accretionary Prism ◽  
Proximal Part ◽  
Late Eocene ◽  
Lithostratigraphic Units ◽  
Stratigraphic Record ◽  
Sea Fan ◽  
Stratigraphic Evolution ◽  
Depositional Setting

AbstractThe Voirons Flysch (Caron in Eclogae Geologicae Helvetiae 69:297–308, 1976), is a flysch sequence aggregated into the sedimentary accretionary prism of the Chablais and Swiss Prealps. Its palaeogeographic location is still debated (South Piemont or Valais realm). We herein present a stratigraphic revision of the westernmost unit of the former Gurnigel Nappe sensu Caron (Eclogae Geologicae Helvetiae 69:297–308, 1976): the Voirons Flysch. This flysch is subdivided into three lithostratigraphic units at the formation level (the Voirons Sandstone, the Vouan Conglomerate, the Boëge Marl), with an additional unit (Bruant Sandstone) of uncertain attribution, ranging from the early Eocene to probably the late Eocene. We further propose a new model of the depositional setting of the deep-sea of the Voirons Flysch based on palaeocurrent directions, the overall geometry and sedimentary features. This model depicts an eastward deflected deep-sea fan. The stratigraphic record of the proximal part of this fan is fairly complete in the Voirons area, whereas its most distal part is only represented by one small exposure of thinly bedded sandstones in the Fenalet quarry. The stratigraphic evolution of the Voirons Flysch shows two major disruptions of the detrital sedimentation at the transition between Voirons Sandstone—Vouan Conglomerate and Vouan Conglomerate—Boëge Marl. The cause of these disturbances has to be constrained in the framework of the palaeogeographic location of the Voirons Flysch.

Retrospective analysis of the appendiceal neoplasms: sampling technique may influence neoplasm detection

2021 ◽  
pp. postgradmedj-2021-141244
Author(s):  
Gizem Issin ◽  
Fatih Demir ◽  
Hasan Aktug Simsek ◽  
Diren Vuslat Cagatay ◽  
Mahir Tayfur ◽  
...  
Keyword(s):  
Retrospective Analysis ◽  
Distal Part ◽  
Histopathological Examination ◽  
Small Diameter ◽  
Sampling Technique ◽  
Proximal Part ◽  
Longitudinal Section ◽  
Appendiceal Neoplasms ◽  
Macroscopic Findings ◽  
Distal Section

Background and aimsAppendiceal neoplasms are uncommon entities that are usually determined incidentally during the histopathological examination. Different techniques used for the macroscopic sampling of appendectomy material may affect the determinating neoplasms.Materials and methodsH&E-stained slides of 1280 cases who underwent appendectomy between 2013 and 2018 were reviewed retrospectively for histopathological features.ResultsNeoplasms were determined in 28 cases (3.09%); 1 lesion was observed in the proximal part of the appendix, 1 covering the entire length from proximal to distal and 26 in the distal part. In the 26 cases that observed in the distal part, the lesion was seen on both sides of the longitudinal section of the distal appendix in 20 cases, while it was seen on only one distal longitudinal section in the remaining 6 cases.ConclusionThe vast majority of appendiceal neoplasms are seen in the distal part of the appendix, and, in some cases, neoplasms might be seen on only one side of the distal section. Sampling only one-half of the distal part of the appendix, where tumours are most often observed, could result in some neoplasms being missed. Therefore, sampling the whole distal part would be more beneficial to determine small diameter tumours that do not create macroscopic findings.

scholarly journals Collecting Duct Is a Site of Sodium Retention in PAN Nephrosis: A Rationale for Amiloride Therapy

2001 ◽  
Vol 12 (3) ◽  
pp. 598-601 ◽  
Author(s):  
GEORGES DESCHÊNES ◽  
MONIKA WITTNER ◽  
ANTONIO DI STEFANO ◽  
SYLVIE JOUNIER ◽  
ALAIN DOUCET
Keyword(s):  
Collecting Duct ◽  
Urinary Sodium Excretion ◽  
Sodium Balance ◽  
Sodium Reabsorption ◽  
Puromycin Aminonucleoside ◽  
Aldosterone Receptor ◽  
Collecting Tubules ◽  
A Site

Abstract. Micropuncture studies of the distal nephron and measurements of Na,K-ATPase activity in microdissected collecting tubules have suggested that renal retention of sodium in puromycin aminonucleoside (PAN) nephrotic rats originates in the collecting duct. The present study demonstrated this hypothesis by in vitro microperfusion and showed that amiloride was able to restore sodium balance. Indeed, isolated perfused cortical collecting ducts from PAN-treated rats exhibited an abnormally high transepithelial sodium reabsorption that was abolished by amiloride, and in vivo administration of amiloride fully prevented decreased urinary sodium excretion and positive sodium balance in nephrotic rats. As expected from the aldosterone independence of Na+ retention in PAN nephrotic rats, blockade of aldosterone receptor by potassium canrenoate did not alter urinary Na+ excretion, Na+ balance, or ascites formation in PAN nephrotic rats.

Effect of Urodilatin Infusion on Renal Haemodynamics, Tubular Function and Vasoactive Hormones

1997 ◽  
Vol 92 (4) ◽  
pp. 397-407 ◽  
Author(s):  
JAN Carstens ◽  
Kaare T. Jensen ◽  
Erling B. Pedersen
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Distal Part ◽  
Renal Haemodynamics ◽  
Sodium Reabsorption ◽  
Lithium Clearance ◽  
Short Term

1. The renal efficacy of urodilatin in humans has only been partly investigated. It is unknown whether intravenously infused urodilatin has an effect on sodium reabsorption in both the proximal and distal part of the nephron. 2. Twelve healthy subjects participated in this double-blind, placebo-controlled study in a crossover design. They received, in a randomized order, a short term (60 min) infusion of urodilatin in three different doses (10, 20 and 40 ng min−1 kg−1 of body weight) and placebo. Renal haemodynamics were estimated by clearance technique with radioactive tracers, and proximal tubular handling of sodium was evaluated by lithium clearance. 3. The 20 ng min−1 kg−1 dose increased the urinary sodium excretion and urinary flow rate compared with the effects of placebo. It increased the glomerular filtration rate and decreased the effective renal plasma flow. In addition, the dose increased the lithium clearance compared with placebo, but did not significantly change the fractional excretion of lithium. On the other hand, it markedly decreased the distal fractional reabsorption of sodium. It also had a suppressive effect on renin secretion. The systemic arterial blood pressure was unchanged, but the dose increased the pulse rate and the haematocrit. The highest dose (40 ng min−1 kg−1) induced a wide variation in the natriuretic and diuretic responses, probably due to a blood-pressure-lowering effect. 4. We conclude, that the urodilatin dose of 20 ng min−1 kg−1 of body weight was most efficacious in this short-term infusion study, and that it had potent natriuretic and diuretic qualities, probably due to stimulation of the glomerular filtration rate and inhibition of sodium reabsorption in the distal part of the nephron.

Stop-flow analysis applied to the excretion of hemoglobin

1960 ◽  
Vol 199 (2) ◽  
pp. 292-294 ◽  
Author(s):  
C. L. Malmendier ◽  
J. P. DeKoster ◽  
F. Vander Veiken ◽  
H. Brauman ◽  
M. DeMyttenaere ◽  
...  
Keyword(s):  
Flow Analysis ◽  
Middle Part ◽  
The Other ◽  
Physiological Data ◽  
Sodium Reabsorption ◽  
Water Reabsorption ◽  
Tubular Lumen ◽  
Influence Of Water ◽  
Stop Flow ◽  
Ureteral Occlusion

The stop-flow analysis has been applied to the study of the excretion of hemoglobin, in order to compare the physiological data with the morphological views. The study of the ratio U/P hemoglobin/U/P creatinine suggests that this protein penetrates the tubular lumen by diffusion during the ureteral occlusion and progressed slowly under influence of water reabsorption. During this migration, hemoglobin undergoes the effects of a double reabsorption: one in the middle part of the proximal convoluted tubule, the other more distally situated in a zone not distinguishable from the site of sodium reabsorption.

Regional differences in potassium content of smooth muscle from opossum esophagus.

1978 ◽  
Vol 235 (6) ◽  
pp. E709
Author(s):  
K Schulze ◽  
J J Hajjar ◽  
J Christensen
Keyword(s):  
Smooth Muscle ◽  
Distal Part ◽  
Proximal Part ◽  
Distal Segment ◽  
Intracellular Concentration ◽  
Potassium Content ◽  
Intracellular Potassium ◽  
The Mean ◽  
Intracellular Potassium Concentration ◽  
Space Volume

Strips from the proximal part of the smooth muscle segment of opossum esophagus have a significantly higher potassium content (50 +/- 3 meq/kg) than those from the distal part (38 +/- 3 meq/kg). There are no significant differences between the two regions in content of sodium (65 +/- 4 meq/kg in proximal, 71 +/- 3 meq/kg in distal) or chloride (48 +/- 10 meq/kg in proximal, 42 +/- 5 meq/ kg in distal). The mean [14C]inulin uptake is 240 +/- 10 ml/kg in both proximal and distal strips. [14C]polyethylene glycol uptake is smaller and [14C]sucrose and [14C]mannitol uptake in both areas are larger than that of inulin. Intracellular potassium concentration (based on the inulin uptake as an estimate of the extracellular space volume) is significantly higher proximally (71 +/- 3 mM) than distally (52 +/- mM). Ouabain, 10(-4) M, increases the intracellular concentration of sodium and decreases the intracellular concentration of potassium in both the proximal and distal segment. The efflux of 86Rb, measured by a washout technique, is higher in the distal than in the proximal smooth muscle segment. A difference in membrane permeability to rubidium and hence, potassium between proximal and distal smooth muscle segments may account in part for the different intracellular potassium concentrations.

Effect of ureteral stop flow on renal tissue creatinine, PAH, K, and P in dogs

1965 ◽  
Vol 209 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Gaspar Carrasquer ◽  
A. Louise Baldwin
Keyword(s):  
Renal Pelvis ◽  
Ureteral Obstruction ◽  
Tissue Concentration ◽  
Renal Tissue ◽  
Free Flow ◽  
Tubular Function ◽  
Sodium Reabsorption ◽  
Phosphorus And Potassium ◽  
And Control ◽  
Stop Flow

Experiments have been designed to study tubular function by analysis of renal tissue under conditions of oliguria and mannitol diuresis. A 50-min ureteral obstruction of one kidney was induced by forcing previously excreted urine into the renal pelvis. Without releasing the obstruction, the experimental and control kidneys were removed simultaneously. Relationships between tissue concentration and tubular function have been demonstrated. Substances that are reabsorbed in medulla accumulate in its interstitium during free flow, and this accumulation is reduced by ureteral obstruction. Persistent filtration during stop flow is manifested by accumulation of creatinine throughout the kidney, and is attributed to a distal leak induced by sodium reabsorption. Accumulation of PAH in cortex is enhanced by ureteral obstruction in mannitol diuresis, but the localized effect on PAH is obscured by high levels of persistent filtration in oliguria. The maintenance of phosphorus and potassium levels during stop flow is attributed to their high intracellular concentrations.

scholarly journals Mini-Laparotomy for Superior Mesenteric Artery Aneurysm Due to Takayasu's Arteritis

2015 ◽  
Vol 100 (4) ◽  
pp. 765-769 ◽  
Author(s):  
Takatsugu Matsumoto ◽  
Mitsuru Ishizuka ◽  
Yukihiro Iso ◽  
Junji Kita ◽  
Keiichi Kubota
Keyword(s):  
Superior Mesenteric Artery ◽  
Mesenteric Artery ◽  
Distal Part ◽  
Takayasu’S Arteritis ◽  
Artery Aneurysm ◽  
Proximal Part ◽  
Whole Body ◽  
Takayasu's Arteritis ◽  
Invasive Approach ◽  
Mini Laparotomy

Superior mesenteric artery aneurysm (SMAA) is reported to be the third-most common type of visceral aneurysm (VA), accounting for 5% of all VAs. The etiology of SMAA is commonly thought to be infection, and it usually exists in the proximal part of the superior mesenteric artery, which is suitable for endovascular treatment. We herein report an extremely rare case of the distal part of SMAA caused by Takayasu's arteritis (TA), which was successfully resected using a mini-laparotomy method without impairing the intestinal blood supply. A 51-year-old woman was admitted to our hospital with sustained fever and lower back pain. Physical examination showed that she had a discrepancies in blood pressure between both arms. Contrast-enhanced whole-body computed tomography showed stenosis of the thoracic aorta and an aneurysm located in the distal part of the superior mesenteric artery. The diameter of the aneurysm was 4.5 cm. The aneurysm was resected via 4-cm mini-laparotomy, and the vascularity of the intestine was successfully preserved. The postoperative course was uneventful, and the patient was diagnosed as having TA based on both clinical and pathologic findings. Additional corticosteroid therapy was started to treat the arteritis, and at 3-month follow-up she was without critical incidents. Mini-laparotomy is a safe and less-invasive approach to treat SMAA, especially when the lesion is located in the distal part of the artery.

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