Electrochemical heterogeneity of the cochlear endolymph: effect of acetazolamide

1984 ◽  
Vol 246 (1) ◽  
pp. F47-F53 ◽  
Author(s):  
O. Sterkers ◽  
G. Saumon ◽  
P. Tran Ba Huy ◽  
E. Ferrary ◽  
C. Amiel
Keyword(s):  
Inner Ear ◽  
Endocochlear Potential ◽  
Electrochemical Gradient ◽  
Acid Base ◽  
Basal Turn ◽  
Ph Values ◽  
Blood Ph ◽  
Acid Base Status ◽  
Electrochemical Heterogeneity ◽  
Inner Ear Fluids

The electrochemical composition of endolymph (EL) of two adjacent cochlear turns was studied in anesthetized rats. Differences in [K]EL, [Cl]EL, and endocochlear potential (EP) were found between the basal turn (165.6 +/- 3.0 mM, n = 14; 144.6 +/- 2.1 mM, n = 14;96.6 +/- 1.9 mV, n = 5, respectively) and the middle turn (155.7 +/- 2.5 mM, n = 15; 133.2 +/- 1.5 mM, n = 15; 87.0 +/- 1.6 mV, n = 6, respectively). The pH values of inner ear fluids were evaluated with 5,5-dimethyloxazolidine-2,4-dione: EL pH of either turn was not different from blood and perilymph (PL) pH. Acetazolamide (40 mg X kg body wt-1) reduced EP and [Cl]EL at each turn by about 20 and 6%, respectively, but [K]EL was unchanged. The electrochemical differences between the two turns persisted. Acetazolamide produced a 0.2-unit decrease in blood pH while the pH values of EL and PL remained unchanged. These results suggest the existence of an electrochemical gradient within EL from the base to the apex of the cochlea involving K+ and Cl- concentrations. H+ and HCO-3 do not appear to participate in this gradient, and the acid-base status in EL could be maintained both by active H+ transport into EL and by HCO-3 formation in the cochlear epithelium.

scholarly journals Effects of External Acidification on the Blood Acid-Base Status and Ion Concentrations of Lamprey

1988 ◽  
Vol 136 (1) ◽  
pp. 351-361
Author(s):  
LEONA MATTSOFF ◽  
MIKKO NIKINMAA
Keyword(s):  
High Sensitivity ◽  
Co2 Concentration ◽  
Acid Base ◽  
Ion Concentrations ◽  
Ph Response ◽  
Ph Values ◽  
Blood Ph ◽  
Acid Base Status ◽  
The Difference ◽  
K Concentration

We studied the effects of acute external acidification on the acid-base status and plasma and red cell ion concentrations of lampreys. Mortality was observed within 24 h at pH5 and especially at pH4. The main reason for the high sensitivity of lampreys to acid water appears to be the large drop in blood pH: 0.6 and 0.8 units after 24 h at pH5 and pH4, respectively. The drop of plasma pH is much larger than in teleost fishes exposed to similar pH values. The difference in the plasma pH response between lampreys and teleosts probably results from the low buffering capacity of lamprey blood, since red cells cannot participate in buffering extracellular acid loads. Acidification also caused a decrease in both Na+ and C− concentrations and an elevation in K+ concentration of plasma. The drop in plasma Na+ concentration occurred faster than the drop in plasma Cl− concentration which, in turn, coincided with the decrease in total CO2 concentration of the blood.

Prenatal maturation of endocochlear potential and electrolyte composition of inner ear fluids in guinea pigs

1983 ◽  
Vol 237 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Yehoash Raphael ◽  
Masaki Ohmura ◽  
Naoyuki Kanoh ◽  
Nobuya Yagi ◽  
Kazuo Makimoto
Keyword(s):  
Inner Ear ◽  
Guinea Pigs ◽  
Endocochlear Potential ◽  
Electrolyte Composition ◽  
Inner Ear Fluids

The Impact of Peritonitis on Peritoneal and Systemic Acid-Base Status of Patients on Continuous Ambulatory Peritoneal Dialysis

1994 ◽  
Vol 14 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Jacques J. Sennesael ◽  
Godelieve C. De Smedt ◽  
Patricia Van der Niepen ◽  
Dierik L. Verbeelen
Keyword(s):  
Staphylococcus Aureus ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Acid Base ◽  
Gram Positive ◽  
Gram Negative ◽  
Arterial Blood ◽  
Blood Ph ◽  
Acid Base Status ◽  
And Staphylococcus Aureus

Objective To assess the possible effects of peritonitis on peritoneal and systemic acid-base status. Design pH, pCO2, lactate, and total leukocyte and differential count were simultaneously determined in the overnight dwell peritoneal dialysis effluent (PDE) and arterial blood in noninfected patients (controls) and on days 1, 3, and 5 from the onset of peritonitis. Setting University multidisciplinary dialysis program. Patients Prospective analysis of 63 peritonitis episodes occurring in 30 adult CAPD patients in a single center. Results In controls, mean (±SD) acid-base parameters were pH 7.41 ±0.05, pCO2 43.5±2.6 mm Hg, lactate 2.5±1.5 mmol/L in the PDE, and pH 7.43±0.04, PaCO2 36.8±3.8 mm Hg, lactate 1.4±0.7 mmol/L in the blood. In sterile (n=6), gram-positive (n=34), and Staphylococcus aureus (n=9) peritonitis PDE pH's on day 1 were, respectively, 7. 29±0.07, 7. 32±0.07, and 7.30±0.08 (p<0.05 vs control). In gram -negative peritonitis (n=14) PDE pH was 7.21 ±0.08 (p<0.05 vs all other groups). A two-to-threefold increase in PDE lactate was observed in all peritonitis groups, but a rise in pCO2 was only seen in gram -negative peritonitis. Acid-base profile of PDE had returned to control values by day 3 in sterile, gram -positive and Staphylococcus aureus peritonitis and by day 5 in gramnegative peritonitis. Despite a slight increase in plasma lactate on the first day of peritonitis, arterial blood pH was not affected by peritonitis. Conclusion PDE pH is decreased in continuous ambulatory peritoneal dialysis (CAPD) peritonitis, even in the absence of bacterial growth. In gram-negative peritonitis, PDE acidosis is more pronounced and prolonged, and pCO2 is markedly increased. Arterial blood pH is not affected by peritonitis.

Acid-base changes in the fetal lamb before and after lung expansion

1963 ◽  
Vol 18 (5) ◽  
pp. 877-880 ◽  
Author(s):  
N. S. Assali ◽  
W. A. Manson ◽  
L. W. Holm ◽  
M. Ross
Keyword(s):  
Blood Oxygen ◽  
Acid Base ◽  
Blood Ph ◽  
Lung Expansion ◽  
Fetal Lamb ◽  
Before And After ◽  
The Status ◽  
Acid Base Status ◽  
Near Term ◽  
Fetal Acidosis

The acid-base status of the fetal lamb was studied in near-term pregnant ewes subjected to spinal anesthesia. The status of the fetus was compared to its mother and the changes which occur after the fetal lungs were ventilated with oxygen or nitrogen were investigated. The results show that: 1) the fetus in utero is in a state of metabolic acidosis in relation to the mother, 2) the acidosis does not seem to be related to the fetal blood pCO2, and 3) the acidosis may be aggravated by hypoxia. fetal acidosis; blood pH; blood oxygen; blood carbon dioxide; hypoxia; hyperoxia; sheep Submitted on March 20, 1963

EFFECT OF TIME OFF FEED ON BLOOD ACID-BASE HOMEOSTASIS IN PIGS DIFFERING IN THEIR REACTION TO HALOTHANE

1987 ◽  
Vol 67 (2) ◽  
pp. 427-436 ◽  
Author(s):  
A. L. SCHAEFER ◽  
H. DOORNENBAL ◽  
A. K. W. TONG ◽  
A. C. MURRAY ◽  
A. P. SATHER
Keyword(s):  
Base Excess ◽  
Venous Blood ◽  
Muscle Rigidity ◽  
Halothane Anesthesia ◽  
Acid Base ◽  
Physiological Factors ◽  
Blood Ph ◽  
Acid Base Status ◽  
Base Stability ◽  
Breed Crosses

In an effort to elucidate physiological factors involved in the development of pale-soft-exudative pork, blood acid base status was assessed in swine from two genetic lines of pigs and their F1 cross. The lines consisted of: (1) pigs that reacted positively (skeletal muscle rigidity) to the respiratory administration of halothane (halothane positive (H+)) based on Pietrain × Lacombe breed crosses, (2) Purebred Lacombe pigs that did not react positively to halothane anesthesia (Lac) and (3) pigs which were the progeny of crossbreeding (C) between halothane positive and negative animals. In addition, time off feed prior to slaughter (0, 24 or 48 h) was imposed as a stressor in order to test response differences among the three lines. The venous blood PCO2, total CO2, bicarbonate ion levels, standard bicarbonate and base excess levels were found to be higher in the H + pigs compared to either Lac or C pigs. All pig lines displayed higher blood pH, total CO2, bicarbonate ion, standard bicarbonate and base excess yet lower PO2 at 24 h off feed compared to 0 h off feed. These data suggest that H+ pigs have a greater tendency toward hypercapnia and a blood base excess than either Lac or C pigs. In addition, the incidence of hypercapnia and blood base excess for H +, Lac and C pigs was greatest at 24 h off feed. Key words: Acid-base stability, pig genotypes, fasting

scholarly journals THE EFFECTS OF SEASONAL VARIATIONS IN TEMPERATURE ON EXTRACELLULAR ACID-BASE STATUS IN A WILD POPULATION OF THE CRAYFISH AUSTROPOTAMOBIUS PALLIPES

1993 ◽  
Vol 181 (1) ◽  
pp. 295-311
Author(s):  
N. M. Whiteley ◽  
E. W. Taylor
Keyword(s):  
Seasonal Variations ◽  
Low Temperatures ◽  
Seasonal Changes ◽  
Wild Population ◽  
Late Summer ◽  
Co2 Solubility ◽  
Acid Base ◽  
Austropotamobius Pallipes ◽  
Ph Values ◽  
Acid Base Status

Between February 1990 and February 1991, a wild population of Austropotamobius pallipes (L.) inhabiting a large, shallow, freshwater pool in Staffordshire, central England, experienced environmental fluctuations in water temperature (1–21°C) and pH (8.2-9.5). Moulting was seasonal, with crayfish entering pre- and postmoult between May and August. Haemolymph pHa levels declined in the spring when temperatures increased from 8 to 18°C (deltapH/deltat=−0.013 pH units°C-1). This decrease was accompanied by a fall in [HCO3-] (of 4.12 mmol l-1) and [lactate] (of 4.71 mmol l-1) and a premoult elevation in PCO2 to 0.59 kPa. After ecdysis, when water temperatures and pH were at their maxima, pHa levels increased, they continued to increase as temperature fell in late summer, reaching 7.97 in intermoult crayfish at 13°C during September. This increase was accompanied by a decrease in PCO2 to 0.22 kPa at constant [HCO3-] (5–6 mmol l-1). Between September (13°C) and October (11°C) pHa fell to 7.87 with an elevation in PCO2 (of 0.18 kPa) and [lactate] (of 1.84 mmol l-1). As temperature continued to decrease (11–1°C), pHa remained unchanged despite an elevation in [HCO3-] by 2.4 mmol l-1 at constant PCO2. A mechanism accounting for the unvarying haemolymph pH values at low temperatures is proposed, stressing the importance of temperature-related seasonal changes in CO2 solubility and measured values for pK1′ in addition to adjustments in [HCO3-] and PCO2. These were apparently unaffected by changes in collecting and holding protocols.

Acid-Base Relationships in the Blood of the Toad, Bufo Marinus: II. The Effects of Dehydration

1979 ◽  
Vol 82 (1) ◽  
pp. 345-355
Author(s):  
R. G. BOUTILIER ◽  
D. J. RANDALL ◽  
G. SHELTON ◽  
D. P. TOEWS
Keyword(s):  
Water Loss ◽  
Respiratory Acidosis ◽  
Acid Base ◽  
Arterial Blood ◽  
Blood Ph ◽  
Acid Base Status ◽  
Toad Bufo ◽  
Circulating Levels ◽  
Bladder Urine ◽  
Co2 Excretion

Cutaneous CO2 excretion is reduced as the skin dries during dehydration but an increase in breath frequency acts to regulate the arterial blood Pcoco2 and thus pHα. Moreover, the toad does not urinate and water is reabsorbed from the bladder to replace that lost by evaporation at the skin and lung surfaces. The animal does, however, produce a very acid bladder urine to conserve circulating levels of plasma [HCO3-] and this together with an increased ventilation effectively maintains the blood acid-base status for up to 48 h of dehydration in air. Water loss and acid production are presumably also reduced by the animal's behaviour; animals remain still, in a crouched position or in a pile if left in groups. Dehydrated toads are less able than hydrated toads to regulate blood pH during hypercapnia: they hyperventilate and mobilize body bicarbonate stores in much the same fashion as hydrated animals but due to the restrictions on cutaneous CO2 excretion and renal output, there is comparatively little reduction in the PCOCO2 difference between arterial blood and inspired gas thereby resulting in a more severe respiratory acidosis. These factors further contribute to the persistent acidosis which continues even when the animals are returned to air.

The Effect of Acidosis on Lactate Removal by the Perfused Rat Kidney

1976 ◽  
Vol 50 (3) ◽  
pp. 185-194 ◽  
Author(s):  
J. Yudkin ◽  
R. D. Cohen
Keyword(s):  
Rat Kidney ◽  
Acid Base ◽  
Ph Values ◽  
Constant Rate ◽  
Perfused Rat Kidney ◽  
Lactate Removal ◽  
Acid Base Status ◽  
Glucose Output ◽  
Normal Acid

1. The isolated perfused kidneys of fed rats in normal acid-base status showed a constant rate of lactate removal from the perfusate between 5 and 90 min of perfusion at a perfusate pH of 7·4–7·5. 2. Lactate removal by kidneys of rats in normal acid-base status was stimulated within 30 min by a reduction in perfusate pH to 7·1–7·2, but depressed when perfusate pH was reduced further. 3. Kidneys taken from rats previously made acidotic and perfused with media of various pH values showed a progressive fall in the rate of lactate removal during the perfusion. 4. Glucose output by the kidneys of rats in normal acid—base status perfused with lactate as substrate was not affected by an alteration in perfusate pH. The kidneys of acidotic rats generally showed an increased rate of glucose output compared with those of control rats.

scholarly journals The effects of prolonged epinephrine infusion on the physiology of the rainbow trout, Salmo gairdneri. I. Blood respiratory, acid-base and ionic states

1987 ◽  
Vol 128 (1) ◽  
pp. 235-253 ◽  
Author(s):  
S. I. Perry ◽  
M. G. Vermette
Keyword(s):  
Rainbow Trout ◽  
Respiratory Acidosis ◽  
Salmo Gairdneri ◽  
Acid Base ◽  
Epinephrine Infusion ◽  
Extracellular Acidosis ◽  
Blood Ph ◽  
Acid Base Status ◽  
Ionic States

Rainbow trout were infused continuously for 24 h with epinephrine in order to elevate circulating levels of this hormone to those measured during periods of acute extracellular acidosis (approximately 5 X 10(−8) mol l-1). Concomitant effects on selected blood respiratory acid-base and ionic variables were evaluated. Infusion of epinephrine caused a transient respiratory acidosis as a result of hypoventilation and/or inhibition of red blood cell (RBC) bicarbonate dehydration. The acidosis was regulated by gradual accumulation of plasma bicarbonate. Even though whole blood pH (pHe) was depressed by 0.16 units, RBC pH (pHi) remained constant, thereby causing the transmembrane pH gradient (pHe-pHi) to decrease. A similar effect of epinephrine on RBC pH was observed in vitro, although the response required a higher concentration of epinephrine (2.0 X 10(−7) mol l-1). We speculate that the release of epinephrine during periods of depressed blood pH is important for preventing excessive shifts in RBC pH and for initiating a series of responses leading to plasma HCO3- accumulation and eventual restoration of blood acid-base status.

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