Parotid Clearance of Sodium and Potassium

1958 ◽  
Vol 195 (3) ◽  
pp. 693-696 ◽  
Author(s):  
L. L. Langley ◽  
C. H. Gunthorpe ◽  
W. A. Beall
Keyword(s):  
Precursor Solution ◽  
Plasma Potassium ◽  
Salivary Flow ◽  
Low Flow ◽  
Parotid Saliva ◽  
Flow Rates ◽  
K Concentration ◽  
Potassium Clearance ◽  
The Relationship ◽  
Sodium And Potassium

A current hypothesis suggests that the mechanism of salivary production involves the formulation of a precursor solution followed by reabsorption of sodium and water but not potassium. Since this is similar to kidney physiology, clearance techniques were used to test the hypothesis. At parotid flow rates below about 0.2 cc/min. the concentration of Na varies directly and that of K indirectly with the flow. At higher rates the K concentration is independent of the flow and closely approximates that of the plasma. Potassium clearance, then, is independent of flow only at very low flows. The concentration of Na in parotid saliva varies with that in the plasma. Extrapolation of the curve cuts the abscissa at a point indicating that if the plasma Na concentration were reduced below approximately 100 mEq/l. no Na would appear in the saliva. The relationship between plasma concentration and the saliva Na/plasma Na ratio is an ascending curve. As the plasma K concentration increases so does the concentration in the parotid saliva. Extrapolation of this curve approaches the origin. The saliva K/plasma K ratio is independent of the plasma K concentration. When K is infused salivary flow rate increases. The infusion of Na decreases flow. These results are consistent with the selective reabsorption theory at low flow rates but there must be another mechanism to explain the findings at higher flows. It is suggested that the influence of Na and K infusion on salivation may be, at least partially, indirect.

Interaction between CO2 concentration and flow rate on peripheral airway resistance

1991 ◽  
Vol 70 (6) ◽  
pp. 2514-2521 ◽  
Author(s):  
A. Kaise ◽  
A. N. Freed ◽  
W. Mitzner
Keyword(s):  
Flow Rate ◽  
Airway Resistance ◽  
Co2 Concentration ◽  
Low Flow ◽  
Flow Rates ◽  
Peripheral Airway ◽  
Residual Capacity ◽  
Local Ventilation ◽  
End Tidal ◽  
The Relationship

In the present study, we investigated the interaction between CO2 concentration and rate of delivered flow on peripheral airway resistance (Rp) in the intact canine lung. Dogs were anesthetized, intubated, paralyzed, and mechanically ventilated with room air to maintain end-tidal CO2 between 4.8 and 5.2%. Using a wedged bronchoscope technique, we measured Rp at functional residual capacity. The relationship between CO2 concentration and Rp was measured at flow rates of 100 and 400 ml/min with 5, 3, 2, 1, and 0% CO2 in air. Measurements were made at the end of a 3-min exposure to each gas. At low flow rates (100 ml/min) responses to hypocapnia were small, whereas at high flow rates (400 ml/min) responses were large. The PC50 (defined as the CO2 concentration required to produce a 50% increase in Rp above baseline Rp established on 5% CO2) at 400 ml/min (1.73%) was significantly larger than that at 100 ml/min (0.38%). We also directly measured the relationship between Rp and flow rate with 5% CO2 (normocapnia) or 1% CO2 (hypocapnia) delivered into the wedged segment. Increases in normocapnic flow caused small but significant decreases in Rp. In contrast, increases in hypocapnic flow from 100 to 400 ml/min caused a 108% increase in Rp. Thus the response to hypocapnia is augmented by increasing flow rate. This interaction can be explained by a simple model that considers the effect of local ventilation-perfusion ratio and gas mixing on the local CO2 concentration at the site of peripheral airway contraction.

Hemodialysis using a Constant Potassium Gradient: Rationale of a Multicenter Study

1995 ◽  
Vol 18 (11) ◽  
pp. 731-734
Author(s):  
B. Redaelli ◽  
D. Limido ◽  
P. Beretta ◽  
M.R. Viganò
Keyword(s):  
Experimental Studies ◽  
Plasma Potassium ◽  
Resting Membrane Potential ◽  
Membrane Hyperpolarization ◽  
Kd Values ◽  
Clinical Consequences ◽  
K Concentration ◽  
The Impact ◽  
The Relationship ◽  
Potassium Gradient

The aim of this study is to evaluate the relationship between two different procedures for potassium removal during hemodialysis (HD) and cardiac arrhythmias. Cell excitability and the transmission of impulses may be influenced by variations of resting membrane potential (RMP). The rapid decrease of plasma potassium during the first two hours of standard HD causes a membrane hyperpolarization. A different K+ kinetic, with a gradual and constant elimination of K+ during HD, may reduce this further unphysiological aspect and its clinical consequences. This can be obtained keeping blood-dialysate K+ gradient as constant as possible with the use of a dialysate K+ concentration (Kd) decreasing during HD. Our experimental studies on various K+ intradialytic gradients seem to indicate as optimal to this purpose K+ gradients of 1.5 mEq/l at the beginning of dialysis, esponentially decreasing during treatment to Kd values of 2.5 mEq/l at the end of dialysis (variable Kd). Patients included in the trial will be submitted to two different methods of treatment with Kd 2 mEq/l and variable Kd, and to a 24 hours ECG the day of dialysis. We will compare the number of intra and interdialytic premature ventricular complexes to evaluate the impact of two different models of potassium removal on arrhythmias.

Effect of acetazolamide on dog parotid saliva

1962 ◽  
Vol 202 (1) ◽  
pp. 158-160 ◽  
Author(s):  
Saul W. Brusilow ◽  
Carmen L. Diaz
Keyword(s):  
Intravenous Administration ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Salivary Flow ◽  
High Flow ◽  
Parotid Saliva ◽  
Parasympathetic Nerve ◽  
Flow Rates ◽  
Stimulation Of

Canine parotid saliva was obtained at varying secretory rates by the stimulation of the postganglionic parasympathetic nerve. Analysis revealed this secretion to have a CO2 content of about 20–30 mEq/liter at low rates of salivary flow to 50– 60 mEq/liter at high flow rates. After the intravenous administration of acetazolamide, the CO2 content at high flow did not rise much above those levels attained at low secretory rates. Acetazolamide also caused decrease of sodium concentration and an increase in chloride concentration at high rates of secretion.

Parotid and Whole-Mouth Secretion in Response to Viewing, Handling, and Sniffing Food

Perception ◽  
1979 ◽  
Vol 8 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Rose Marie Pangborn ◽  
Steven A Witherly ◽  
Frances Jones
Keyword(s):  
Salivary Flow ◽  
Lemon Juice ◽  
Affective Responses ◽  
Parotid Saliva ◽  
Flow Rates ◽  
Full Strength ◽  
Significant Change ◽  
Secretion Rates ◽  
Stimulation Of

There was no significant change in flow rates of parotid saliva in nineteen of twenty subjects while they viewed photographs of lemons, or in fourteen of twenty subjects while they cut lemons in a glove box. Neither parotid nor whole-mouth secretion changed from baseline when subjects viewed fresh lemons and lemonade presented in a plastic box. Further, no significant changes in whole-mouth secretion rates were observed when subjects viewed photographs of two appetizing foods, or of fresh doughnuts in a plastic box, even though subjects knew they could eat the doughnuts after the experiment. In most cases, sniffing of the lemons or of the doughnuts resulted in increased flow rates. Subjects demonstrated large differences in their patterns of affective responses to full-strength and diluted lemon juice, which were independent of salivary flow. In the absence of olfactory or tactile stimulations, few subjects altered parotid or whole-mouth secretion rates in response to viewing food or photographs of food. A reevaluation of findings on ‘psychic’ stimulation of saliva may be in order to ascertain the role of olfactory, tactile, and even trigeminal clues in salivary response to food stimuli.

A comparison of two non-radioactive digesta marker systems for the measurement of nutrient flow at the proximal duodenum of calves

1978 ◽  
Vol 90 (1) ◽  
pp. 157-163 ◽  
Author(s):  
D. E. Beever ◽  
R. C. Kellaway ◽  
D. J. Thomson ◽  
J. C. MacRae ◽  
C. C. Evans ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Low Flow ◽  
Dual Phase ◽  
Regression Equations ◽  
Flow Rates ◽  
Proximal Duodenum ◽  
Dietary Component ◽  
Sodium And Potassium

SUMMARYThe use of non-radioactive ruthenium phenanthroline (Ru-P) and chromium EDTA (Cr-EDTA) as dual phase markers of digesta flow was examined and compared with chromium sesquioxide (Cr2O3) in conjunction with spot samples of digesta collected from T-shaped cannulae situated in the proximal duodenum of weaned calves.In vitro estimates of organic matter digestibility indicated that on a cubed barley diet, Ru-P exhibited toxic effects at concentrations on 2·2 × 10–5 M and above. No such effects were noted with Cr-EDTA. Subsequently satisfactory infusion rates of 12 mg Ru and 280 mg Cr/kg dry-matter intake were established.Daily flows of organic matter, starch, nitrogen, fibre, sodium and potassium at the proximal duodenum were calculated by the dual phase marker system and by Cr2O3, and regression equations relating these two for each dietary component were calculated. Examination of the intercepts revealed that they all differed significantly from zero (P < 0·05) whilst all the regression coefficients were significantly different from unity (P < 0·05), thus indicating that Cr2O3 underestimated nutrient flows at low flow rates and overestimated them at high flow rates relative to the corresponding estimates based on Ru-P plus Cr-EDTA.

Composition of Parotid and Submandibular Saliva and Serum in Down's Syndrome

1972 ◽  
Vol 51 (2) ◽  
pp. 449-454 ◽  
Author(s):  
Richard A. Winer ◽  
Ralph P. Feller
Keyword(s):  
Uric Acid ◽  
Total Protein ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Salivary Flow ◽  
Parotid Saliva ◽  
Flow Rates ◽  
Submandibular Saliva

Parotid saliva, submandibular saliva, and blood were collected from mongoloid and nonmongoloid populations. Salivary flow rates were determined and fluid samples were analyzed for various electrolytes. Ten samples of parotid saliva and serum were analyzed for total protein, creatinine, amylase, and uric acid. Parotid saliva of mongoloids showed some differences in composition, but serum showed only a higher level of uric acid.

scholarly journals Salivary Electrolyte Concentrations and Electrical Potential Difference Across the Parotid Salivary Duct of Anaesthetized Sodium-Replete Sheep

1980 ◽  
Vol 33 (2) ◽  
pp. 197
Author(s):  
AM Beal
Keyword(s):  
Flow Rate ◽  
Electrical Potential ◽  
Chloride Concentration ◽  
Salivary Flow ◽  
Potential Difference ◽  
Electrical Potential Difference ◽  
Parotid Saliva ◽  
Potential Measurement ◽  
Flow Rates ◽  
Parotid Duct

Salivary flow rate and the concentrations of electrolytes in parotid saliva and arterial plasma from anaesthetized sodium-replete sheep were measured before, during and after ipsilateral intracarotid infusion of acetylcholine at 10 nmol min -1 to ascertain whether anaesthesia altered the relation between salivary flow and sodium concentration. The potential difference (PO) between the lumen of the parotid duct and the vascular system was also measured. Concentrations of salivary sodium and phosphate were decreased and potassium concentration and total CO2 content were increased when rate of salivary flow was increased by acetylcholine infusion. Salivary chloride concentration was reduced in five experiments and increased in three experiments when flow rate was elevated. Thus the flow-composition relations of parotid saliva from anaesthetized sheep were essentially the same as those for saliva from conscious animals. The PO between the lumen of the parotid duct and blood at resting flow rates was 9�4� 1�07 mY, lumen negative. At high flow rates, stimulated by acetylcholine infusion, the PO increased to 21� 9 � 2� 20 mY, lumen negative. This increase in PO of the duct epithelium appeared to depend on changes in the composition of saliva arriving at the site of potential measurement.

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