Plasma Chloride Concentrations Research Articles

Growth hormone and cortisol treatment stimulate seawater tolerance in both anadromous and landlocked Arctic charr

In a comparative experiment the effect of cortisol and growth hormone (GH) on the hypo-osmoregulatory ability of a landlocked and an anadromous strain of Arctic charr ( Salvelinus alpinus) was investigated. Cortisol and GH were implanted either alone or in combination, and the fish were exposed to a 24 h seawater challenge test (SWT) on days 14 and 28 after implantation. Hypo-osmoregulatory ability, measured as plasma osmolality and chloride concentration after the SWTs, was better in the anadromous than in the landlocked strain, irrespective of treatment. However, cortisol provided a strong stimulation of hypo-osmoregualtory ability in both strains, and this stimulation seemed to be potentiated by GH in an additive manner. Improved hypo-osmoregulatory ability in GH + cortisol treated anadromous Arctic charr was accompanied by increased gill Na +, K +-ATPase activity and Na +–K +–2Cl − cotransporter protein abundance, but no changes in gill Na +,K +-ATPase α1a and α1b mRNA levels. For landlocked charr the improved hypo-osmoregulatory ability in GH +cortisol treated fish was accompanied only with an increase in gill Na +–K +–2Cl − cotransporter protein abundance. Hormone treatment caused an improvement of hypo-osmoregulatory ability that was of approximately the same magnitude in the landlocked as in the anadromous Arctic charr. This suggests that the lack of spontaneous development of hypo-osmoregulatory ability often seen in landlocked populations of Arctic charr may depend, at least partly, on a lack of the hormonal activation seen in anadromous populations.

Salinity effects on the expression of osmoregulatory genes in the euryhaline black porgy Acanthopagrus schlegeli

Black porgy is a marine euryhaline species with a capacity to cope with demands in a wide range of salinities and thus is a perfect model-fish to study osmoregulatory responses to salinity-acclimated processes and their hormonal control. The present study was performed to understand the regulatory changes in hormone, hormone receptors and important osmoregulatory genes in pituitary, gill, intestine and kidney in response to acute salinity stress. Transcript levels were analyzed by quantitative real-time PCR following acute salinity challenge by direct transfer of seawater (SW) acclimatized fish to fresh water (FWBP) and vice versa (SWBP). SW acclimation significantly increased plasma osmolality and intestine Na +/K +-ATPase (NKA) activity while FW acclimation increased plasma cortisol and branchial NKA activity. Plasma osmolality and chloride concentration decreased in FWBP whereas GH levels remained unchanged in both FWBP and SWBP. Comparative analysis of gene profiles between FWBP and SWBP showed that pituitary prolactin transcript increased significantly in FWBP. Prolactin receptor ( PRLR) transcripts increased in gill of FWBP while it decreased in gill and kidney of SWBP. NKA transcripts increased in gill of both FWBP and SWBP, while it decreased in intestine of FWBP and increased in intestine and kidney of SWBP. Glucocorticoid receptor ( GR) transcripts decreased in intestine and kidney of FWBP while it increased in gill and intestine of SWBP. No significant changes were observed in growth hormone receptor ( GHR) transcripts of both FWBP and SWBP in pituitary, gill, intestine and kidney. Our current data demonstrated the correlation between PRLR gene expression in relation to FW adaptation, and GR gene expression in relation to SW adaptation in euryhaline black porgy. The results indicate that black porgy has an excellent osmoregulatory capacity and is capable of withstanding large variations in salinity.

Physiology and behaviour of Atlantic salmon ( Salmo salar) smolts during commercial land and sea transport

This study examined the physiology (plasma cortisol, glucose, lactate, potassium, sodium and chloride concentrations) and behaviour (underwater video footage) of commercially produced Atlantic salmon ( Salmo salar) smolts during transport from freshwater farms to saltwater net pens. Smolts were transported by truck in closed tanks from two freshwater farms to the dock (30–60 min), and then in the flow-through cargo holds of a live-haul vessel, the Sterling Carrier, to the saltwater net pens (~ 2 h). Some fish were dockside in the vessel for up to 8 h while successive deliveries were loaded into the holds. Fish and water were sampled both before and after truck transport, and then at several time points aboard the vessel. Analysis of plasma constituents showed modest primary and secondary stress responses due to loading and truck transport, and the recovery that occurred dockside in the live-haul vessel was maintained when the vessel was underway. Underwater video footage revealed behavioural differences between fish from the two freshwater facilities that were not evident from the physiological measurements, but the behaviours observed during transport on a live-haul vessel were consistent with a non-stressful environment. Although smolts were subjected to moderately stressful conditions during loading and trucking, they began to recover rapidly aboard the Sterling Carrier. We therefore conclude that smolt transport, as currently conducted by our industry partner, appears to reflect good fish welfare.

Higher Lipid Peroxidation Indices in Horses Eliminated from Endurance Race Because of Synchronous Diaphragmatic Flutter (Thumps)

Abstract Eighteen racing horses from a total of 85 horses that participated in a long-distance (120-km) race were used for this study. The 18 horses that were used comprised nine horses that were eliminated from the race at the 90-km checkpoint because of synchronous diaphragmatic flutter (SDF). Another nine horses that passed the 90-km checkpoint were randomly selected and served as a control group (CT). Horses were sampled at three different times (t 0, t end, t 2weeks). Plasma sodium (Na +), potassium (K +), and chloride (Cl −) concentrations were decreased at the end of the race to insignificant levels. A significant reduction ( P ≤ .05) was observed in the ionized calcium (Ca ++). Lipid peroxide (LPO) and malondialdehyde (MDA) concentrations in plasma were higher compared with values obtained before the start of the race. In SDF-eliminated horses, these parameters were higher than in the control horses. Glutathione peroxidase (GSH-Px) activity was significantly lower at the end of the race, whereas creatine phosphokinase (CPK) was similarly increased fourfold in both groups. A significant increase in lactate concentration was seen in both groups; however, this parameter was significantly higher in the SDF-eliminated horses than in the control group. Statistical significance ( P < .01) was observed between LPO and MDA levels and the Ca ++ concentration in the SDF group at the three sampling points. This study established elevated lipid peroxidation product level as one component of the biochemical characteristics of SDF. The low level of Ca ++ in plasma of horses was associated with high levels of lipid peroxidation indexes.

Short‐term low‐salinity tolerance by the longhorn sculpin, Myoxocephalus octodecimspinosus

The bottom-dwelling, longhorn sculpin, Myoxocephalus octodecimspinosus, is traditionally viewed as a stenohaline marine fish, but fishermen have described finding this sculpin in estuaries during high tide. Little is known about the salinity tolerance of the longhorn sculpin; thus, the purposes of these experiments were to explore the effects of low environmental salinity on ion transporter expression and distribution in the longhorn sculpin gill. Longhorn sculpin were acclimated to either 100% seawater (SW, sham), 20% SW, or 10% SW for 24 or 72 hr. Plasma osmolality, sodium, potassium, and chloride concentrations were not different between the 20 and 100% treatments; however, they were 20-25% lower with exposure to 10% SW at 24 and 72 hr. In the teleost gill, regulation of Na(+), K(+)-ATPase (NKA), Na(+)-K(+)-2Cl(-) cotransporter (NKCC1), and the chloride channel, cystic fibrosis transmembrane conductance regulator (CFTR) are necessary for ion homeostasis. We immunolocalized these proteins to the mitochondrion-rich cell of the gill and determined that acclimation to low salinity does not affect their localization. Also, there was not a downregulation of gill NKA, NKCC1, and CFTR mRNA or protein during acclimation to low salinities. Collectively, these results suggest that down to 20% SW longhorn sculpin are capable of completely regulating ion levels over a 72-hr period, whereas 10% SW exposure results in a significant loss of ions and no change in ion transporter density or localization in the gill. We conclude that longhorn sculpin can tolerate low-salinity environments for days but, because they cannot regulate ion transporter density, they are unable to tolerate low salinity for longer periods or enter freshwater (FW). The genus Myoxocephalus has three FW species, making this group an excellent model to test evolutionary and physiological mechanisms that allow teleosts to invade new low salinities successfully.

Effects of fruits and vegetables on electolytes and blood pressure of hypertensive patients seen in Nigeria

High-fruit and high-vegetable diets are known to have ameliorating effects on many diseases and their complications. The objective of this study was to assess the effects of high fruit and high vegetable diets on the electrolytes and blood pressure of hypertensive patients. This experimental study was conducted at Olabisi Onabanjo University Teaching Hospital (formerly Ogun State University), Ogun state, Nigeria. Twenty five hypertensive volunteers from among hypertensive clinic attendees were recruited into the study. They were taught how to prepare two serves of vegetables and fruit (approximately 500g diced fruit salad) per day and were encouraged to consume the serves on daily basis from week one through to week ten. Baseline and bi-weekly assessment of plasma electrolytes, such as sodium, potassium, chloride and bicarbonate was carried out on the patients. Anthropometric measurements and blood pressure were also assessed biweekly on the patients during their routine clinic attendance. There was a gradual reduction in plasma sodium and chloride concentrations as well as the blood pressure which became significant in week ten. The mean baseline plasma sodium reduced significantly from 139.0 ± 0.9mmo/L to 137.5 ± 0.9mml/L, P < 0.001 after ten weeks of high fruit and high vegetable diets. Plasma chloride also reduced from baseline value of 103.2 ± 2.5mmol/L to 98.8 ± 0.7mmol/L, P < 0.0001. But the plasma potassium improved from 3.64 ± 0.2mmol/L at baseline to 3.9 ± 0.4mmol/L at week ten, P = 0.0357. The mean systolic blood pressure also dropped from the baseline value of 155.3± 7.6mmHg to 141 ± 2.4 mmHg, P < 0.0001. Also reduced was the mean diastolic blood pressure from 89.3 ± 7.6mmHg to 88.0 ± 2.4, at week ten. However, the plasma bicarbonate and BMI did not charge significantly throughout the study period. High-fruit and high-vegetable diets appear to have an ameliorating effect on the blood pressure of hypertensive patients. This may be beneficial and complementary in the management of hypertension. Keywords: Hypertension, Fruits and Vegetables, Electrolytes. AJFAND Vol. 8 (3) 2008: pp. 349-357

Alteration of anion gap and strong ion difference caused by hydroxyethyl starch 6% (130/0.42) and gelatin 4% in children

Synthetic colloid administration is a common practice for preventing perioperative hypovolemia and consecutive circulatory failure in children. This prospective, randomized study was conducted to investigate the effects of two different unbalanced synthetic colloid solutions on acid-base equilibrium in children. Fifty pediatric patients (aged 0-12 years) scheduled for major pediatric surgery were randomized to receive either 10 ml x kg(-1) of 6% hydroxyethyl starch solution 130/0.42 (HES) or 4% modified fluid gelatin (GEL) to maintain adequate systemic hemodynamics. Before and after colloid administration, a blood sample was collected to analyze hemoglobin, hematocrit, electrolytes, and acid-base parameters. The anion gap and the strong ion difference (SID) were calculated using standard formulas. Both HES and GEL administration caused a significant increase in plasma chloride concentration (P < 0.01) and an accompanying decrease in SID (P < 0.01). In the HES group, the anion gap decreased significantly (P < 0.01) whereas the anion gap remained stable in the GEL group. In both groups, initial actual base excess and pH did not change significantly after colloid administration. Moderate intraoperative plasma replacement with unbalanced synthetic colloids HES and GEL leads to a decrease in SID and, in the case of HES, to a significant decrease in the anion gap in children. These alterations may result in a possible misinterpretation when the anion gap and SID are used for differential diagnosis of metabolic disturbances during major pediatric surgery.

Comparison of parr–smolt transformation in hatchery reared offspring of one domesticated and two wild populations of Atlantic salmon (Salmo salar L.)

The objective of this study was to compare the parr–smolt transformation of hatchery reared offspring of one cultured strain (Aqua Gen) and two wild Norwegian populations (Namsen and Alta) of Atlantic salmon. The fish were held in freshwater at two different temperatures (3 and 10 °C) under a simulated natural photoperiod (69°N). Changes in condition factor and gill Na+/K+–ATPase activity of freshwater adapted fish, and plasma osmolality and Cl-concentration following seawater challenge tests at 6 °C, were measured on nine occasions during spring. The fish from each of the three experimental groups went through a successful parr–smolt transformation, characterised by reduced condition factor, increased Na+/K+–ATPase activity in the gills, and decreased plasma osmolality and plasma chloride concentration after challenge to seawater. The development of smoltification indices was advanced by 2–3 months in fish held at 10 °C, as compared to that displayed by the fish held at 3 °C. At 3 °C, there were no apparent differences in the development of smolting characters between the strains. However, at 10 °C the Aqua Gen strain developed full seawater tolerance approximately one month earlier (mid-March) than the Namsen strain (late April) and also showed a shaper de-smoltification delineation later in the experiment. The results from the present study suggest that there are genetic components affecting the time-pattern of smoltification and de-smoltification between strains of Atlantic salmon.

Electrolyte depletion and osmotic imbalance in amphibians with chytridiomycosis

Mounting evidence implicates the disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis, in global amphibian declines and extinctions. While the virulence of this disease has been clearly demonstrated, there is, as yet, no mechanistic explanation for how B. dendrobatidis kills amphibians. To investigate the pathology of chytridiomycosis, blood samples were collected from uninfected, aclinically infected and clinically diseased amphibians and analyzed for a wide range of biochemical and hematological parameters. Here, we show that green tree frogs Litoria caerulea with severe chytridiomycosis had reduced plasma osmolality, sodium, potassium, magnesium and chloride concentrations. Stable plasma albumin, hematocrit and urea levels indicated that hydration status was unaffected, signifying depletion of electrolytes from circulation rather than dilution due to increased water uptake. We suggest that B. dendrobatidis kills amphibians by disrupting normal epidermal functioning, leading to osmotic imbalance through loss of electrolytes. Determining how B. dendrobatidis kills amphibians is fundamental to understanding the host-pathogen relationship and thus the population declines attributed to B. dendrobatidis. Understanding the mechanisms of mortality may also explain interspecific variation in susceptibility to chytridiomycosis.

Semen of Perca fluviatilis L.: Sperm volume and density, seminal plasma indices and effects of dilution ratio, ions and osmolality on sperm motility

The objectives of the present study were to characterize sperm volume and density, seminal plasma indices (ionic contents and osmolality) and to study the effects of dilution ratio, ions and osmolality on sperm motility parameters (percentage of motile sperm and sperm velocity) in farmed European perch ( Perca fluviatilis L.). The means of sperm volume (ml), sperm density (×10 9 sperm ml −1) and total number of sperm (volume × density) per fish were 2.75 ± 0.51, 29.19 ± 3.15 and 82.19 ± 15.26. The seminal plasma osmolality (mOsm kg −1), sodium, chloride, potassium and calcium ions concentrations (mM) were measured to be 298.07 ± 5.09, 130.97 ± 2.19, 106.75 ± 2.37, 10.70 ± 0.61 and 2.41 ± 0.09, respectively. At 15 s post-activation of stripped sperm, the percentage of motile sperm (%) and sperm velocity (μm s −1) were 91.90 ± 1.27 and 115.54 ± 1.25, respectively, and decreased significantly following sperm activation ( P < 0.05). The optimal sperm motility was observed when the sperm was prediluted in immobilizing solution (IS) at a ratio 1:50. Prediluted sperm showed the maximum velocity when activated in 2.5 mM Ca 2+, 50 mM K + and sucrose with osmolality 100 mOsm kg −1. Neither Ca 2+ nor K + showed a significant effect on the percentage of motile sperm at 15 s post-activation. Osmolality higher than 200 mOsm kg −1 significantly decreased the percentage of motile sperm, while osmolality of 300 mOsm kg −1 or above totally suppressed sperm motility.

Impacts of feeding several components of the seaweed Ascophyllum nodosum on transported lambs

Feeding the seaweed Ascophylum nodosum (ANOD) has been previously shown to mediate the body temperature of lambs during transport in hot weather while also negatively impacting antibody production. The aim of this study was to determine if fucoidan, salt (NaCl plus potassium gluconate) or betaine, were the causative agents for the effects seen in previous studies. Each compound was fed at a rate to approximate the intake when consuming 30 g of ANOD per day. Two additional groups were fed either 30 g of ANOD per day or capsules filled with grain ( i.e., controls). Fifty-five lambs (19 ewes and 34 wethers) averaging 25 ± 7 kg were used. Each lamb swallowed three gelatin capsules twice daily filled with the appropriate amount of treatment compound for 14 days. Prior to supplementation, all lambs had similar plasma cortisol and aldosterone concentrations. ANOD-supplemented lambs had suppressed (P<0.05) IgG and IgM antibody titers in response to administration of ovalbumin, and tended (P=0.10) to have higher white blood cell counts and more eosinophils (P=0.10) and lymphocytes (P=0.06) than the controls post-supplementation. Salt-fed lambs showed an increase in lymphocyte (P=0.06) counts while betaine-fed lambs had higher (P<0.05) packed cell volume and hemoglobin relative to the controls. Post-supplementation ANOD-fed and salt-fed lambs tended to have lower cortisol concentrations (P=0.08 and 0.12) than controls and all treatments had a trend (P=0.10, 0.07, 0.14, and 0.09) to lower aldosterone concentrations relative to controls. All lambs had similar mean, minimum, maximum, and range of body temperature during transport, although ANOD-fed lambs had less fluctuation in their body temperature than controls. During transport the salt-fed lambs had lower (P<0.05) cortisol concentrations than controls. Control lambs tended to have higher plasma sodium and chloride concentrations (P<0.10) post-transport than ANOD-fed lambs. All lambs lost a similar amount of body weight due to transport. Post-transport, no differences occurred in the latency of lambs to drink, eat or lie down. None of the components studied appeared to be impacting the mediation of body temperature that ANOD exhibits. The salts in ANOD appears to affect both adrenal and immune function, although further studies are needed to determine the mechanism by which it caused such large physiological impacts.

Effects of Long-term Heat Exposure on Adaptive Mechanism of Blood Acid-base in Buffalo Calves

In order to investigate the mechanism of adaptation to long-term heat stress, six female buffalo calves of about 7 to 8 months age, were exposed to the cool-comfort environment (THI 65) for 21 days to obtain normal values of blood acid-base. An adaptive response of acid-base regulation was determined to long term (21 days) exposure of buffalo calves to hot-dry (THI 80) and hot-humid (THI 84) conditions. Higher rectal temperature and respiratory rate was recorded under hot-humid exposure compared to hot-dry. Significant reduction in the rectal temperature and respiratory rate on day 21 of hot-dry exposure indicated early thermal adaptation compared to hot-humid. Decreasing rectal temperature and respiratory rate from day 1 to 21 was associated with concurrent decrease in blood pH and pCO 2 . Increased plasma chloride concentration with low base excess in blood and in extracellular fluid suggested compensatory response to respiratory alkalosis. Reduced fractional excretion of sodium with increased fractional excretion of potassium and urine flow rate indicated renal adaptive response to heat stress.

Blood Biochemical and Ruminal Liquor Profile in Buffaloes (Bubalus bubalis) Showing Omasal Impaction

The blood biochemical and ruminal fluid parameters of 5 buffaloes showing omasal impaction were studied, together with 10 healthy buffaloes as control. The diseased buffaloes had significantly higher serum aspartate aminotransferase, bilirubin, glucose, blood urea nitrogen, creatinine, total protein, globulin and fibrinogen levels and significantly lower plasma calcium, potassium and chloride concentrations than the controls. The ruminal liquor of the diseased buffaloes revealed characteristic physical, chemical and microbial changes and had significantly higher methylene blue reduction time and ammonia-nitrogen level.

Pathophysiology of Cultured Tiger Puffer Takifugu rubripes Suffering from the Myxosporean Emaciation Disease

The present study suggests that the myxosporean emaciation disease by enteric infection of Enteromyxum leei disrupts intestinal water uptake of tiger puffer Takifugu rubripes. This idea is based on a significant negative correlation between plasma chloride concentration and condition factor in diseased fish, and significantly higher osmolarity of plasma and major ion con- centrations of the intestinal fluid in infected fish than in healthy control fish. Additionally, surgical ligation of the junction between the stomach and the intestine of healthy fish resulted in a 24% drop of body weight within 50 h, and significantly lower water content of the white muscle (operated fish 74 ± 0.5%; sham-operated fish 82 ± 1%). However, in vitro water uptake by isolated intestine sacs was not significantly different between the control and infected fish. Meanwhile, hepatic function appeared to be impaired as evidenced by the significantly lower hepato-somatic index (control fish 8.7 ± 0.8%; infected fish 2.7 ± 0.8%). Plasma activities of LDH, AST and ALT were all significantly lower in the infected fish. We propose that rapid loss of body weight of infected tiger puffer is mainly due to osmoregulatory failure but probably malnutrition is also involved in the pathogenesis.

Cambios en la concentración de iones y en el volumen plasmático después de un partido de tenis individual femenino

Objective To determine possible electrolyte changes induced by competitive tennis in young female players. Material and methods Ten female tennis players (mean ± SEM age: 15.6 ± 0.87 years, height: 164.55 ± 1.98 cm, weight: 58.77 ± 2.08 kg) were selected to participate in an official tennis tournament. A blood sample (15 mL) was obtained 30 minutes before the tournament. After extraction, the players drank 500 mL of water before the match. Water intake (ad libitum) and heart rate (HR) were recorded during the match. The matches were recorded on video. Another blood sample was obtained at the end of the match. The variables analyzed were HR, total play time, real play time, rest time, plasma electrolyte concentrations (sodium, potassium and chloride), and total plasma proteins to determine plasma volume changes. Results Total play time was 99.6 ± 18.5 min and mean HR during the match was 158.4 ± 1.98 bpm-1. After the match, an increase in plasma volume (3.59 ± 2.56%) and a decrease in body weight (−1.31 ± 0.27) were observed, as well as a significant rise in plasma sodium (136.98 ± 1.71 to 145.77 ± 1.77) and chloride concentrations (92.17 ± 1.21 a 100.12 ± 1.31) compared with those registered before the match (p ≤ 0,001). Plasma potassium concentration decreased slightly (3.90 ± 0.13 to 3.13 ± 0.19) (p ≤ 0.01). Discussion Hydration should be controlled in tennis players to avoid electrolyte imbalance.

CLINICAL BIOCHEMISTRY IN HEALTHY MANATEES (TRICHECHUS MANATUS LATIROSTRIS)

Florida manatees (Trichechus manatus latirostris) are endangered aquatic mammals living in coastal and riverine waterways of Florida and adjacent states. Serum or plasma biochemical analyses are important tools in evaluating the health of free-ranging and captive manatees. The purpose of this study was to measure diagnostically important analytes in the plasma of healthy manatees and to determine whether there was significant variation with respect to location (free-ranging versus captive), age class (small calves, large calves, subadults, adults), and gender. No significant differences in plasma sodium, potassium, bilirubin, glucose, alanine aminotransferase, or creatine kinase were found among these classes of animals. Compared to free-ranging manatees, captive animals had significantly lower mean concentrations of plasma chloride, phosphate, magnesium, triglycerides, anion gap, and lactate. Captive manatees had significantly higher mean values of total CO2, calcium, urea, creatinine, alkaline phosphatase, gamma-glutamyltransferase, total protein, albumin, and albumin/globulin ratio than did free-ranging animals. Differences in the environments of these two groups, including diet, temperature, salinity, and stress, might account for some of these results. The higher plasma lactate and anion gap concentrations and lower total CO2 concentrations of free-ranging manatees were probably due to greater exertion during capture, but the lack of elevated plasma creatine kinase activity relative to captive animals indicates that there was no serious muscle injury associated with capture. Plasma phosphate decreased and total globulins increased with age. Plasma cholesterol and triglyceride concentrations were highest in small calves. Plasma aspartate aminotransferase was higher in large calves than in adults and subadults, and the albumin/ globulin ratio was higher in subadults than in adults. Plasma total CO2 was higher and chloride was slightly lower in females than in males.

Renal compensation to chronic hypoxic hypercapnia: downregulation of pendrin and adaptation of the proximal tubule

The molecular basis for the renal compensation to respiratory acidosis and specifically the role of pendrin in this condition are unclear. Therefore, we studied the adaptation of the proximal tubule and the collecting duct to respiratory acidosis. Male Wistar-Hannover rats were exposed to either hypercapnia and hypoxia [8% CO(2) and 13% O(2) (hypercapnic, n = 6) or normal air (controls, n = 6)] in an environmental chamber for 10 days and were killed under the same atmosphere. In hypercapnic rats, arterial pH was lower than controls (7.31 +/- 0.01 vs. 7.39 +/- 0.01, P = 0.03), blood HCO(3)(-) concentration was increased (42 +/- 0.9 vs. 32 +/- 0.24 mM, P < 0.001), arterial Pco(2) was increased (10.76 +/- 0.4 vs. 7.20 +/- 0.4 kPa, P < 0.001), and plasma chloride concentration was decreased (92.2 +/- 0.7 vs. 97.2 +/- 0.5 mM, P < 0.001). Plasma aldosterone levels were unchanged. In the proximal tubule, immunoblotting showed an increased expression of sodium/bicarbonate exchanger protein (188 +/- 22 vs. 100 +/- 11%, P = 0.005), confirmed by immunohistochemistry. Total Na/H exchanger protein expression in the cortex was unchanged by immunoblotting (119 +/- 10 vs. 100 +/- 11%, P = 0.27) and immunohistochemistry. In the cortex, the abundance of pendrin was decreased (51 +/- 9 vs. 100 +/- 7%, P = 0.003) by immunoblotting. Immunohistochemistry revealed that this decrease was clear in both cortical collecting ducts (CCDs) and connecting tubules (CNTs). This demonstrates that pendrin expression can be regulated in acidotic animals with no changes in aldosterone levels and no external chloride load. This reduction of pendrin expression may help in redirecting the CNT and CCD toward chloride excretion and bicarbonate reabsorption, contributing to the increased plasma bicarbonate and decreased plasma chloride of chronic respiratory acidosis.

Assessment of the use of plasma and serum chloride concentrations as indirect predictors of serum bromide concentrations in dogs with idiopathic epilepsy

Bromide (BR) administration causes pseudohyperchloremia when plasma or serum chloride (Cl-) concentrations are determined with commonly available automated analytical assays. In humans receiving BR, it has been previously demonstrated that the plasma Cl- concentration is a useful indirect estimator of the measured BR concentration. The objective of this study was to determine if the magnitude of pseudohyperchloremia seen in epileptic dogs treated with BR could be used as a predictor of the measured serum BR concentration. Plasma and serum Cl- concentrations, analyzed by ion-specific electrode (ISE) and colorimetric techniques, and serum BR concentrations, determined using the gold-trichloride assay, were simultaneously determined in 88 blood samples from dogs with idiopathic epilepsy that were treated with BR. For all methods used to quantify Cl- concentrations, there were significant (P < .0001) linear relationships between BR and Cl- concentrations. Linear relationships between BR and Cl- concentrations were significantly different (P < .0001) between blood samples from dogs obtained during routine therapeutic monitoring and those obtained during emergency hospital admissions. Calculated 95% prediction intervals for future values of BR using measured Cl- concentrations contained considerable error. Plasma Cl- values determined with ISE generally provided the best prediction of serum BR concentrations. Agreement between the measured BR and Cl- using all Cl- assay techniques was moderate, but was statistically significant only when Cl- was assayed in plasma using one ISE method. The pseudohyperchloremia observed in epileptic dogs receiving BR is an inadequate indirect estimator for the measured BR concentration, although in certain clinical situations identified through construction of a clinical decision tree, the measured Cl- value can be used to guide general therapeutic decisions regarding alterations in BR therapy. Optimal tailoring of BR therapy in dogs with idiopathic epilepsy should be based on results of therapeutic monitoring of BR concentrations.

Evaluation of bithionol as a bath treatment for amoebic gill disease caused by Neoparamoeba spp.

This study examined the toxicity of bithionol to Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss in fresh- and seawater and the efficacy of bithionol as a 1 h seawater bath treatment for amoebic gill disease (AGD). To examine toxicity, fish were bathed for 1, 3 and 6 h in bithionol, an anti-protozoal at 0, 1, 5, 10, 25 and 35 mg L −1 with toxicity determined by time to morbidity. Efficacy was examined by bathing AGD-affected Atlantic salmon and rainbow trout for 1 h at bithionol concentrations of 1–25 mg L −1. Efficacy was determined by examining gill amoeba counts and identifying percent lesioned gill filaments at 1 and 24 h after bath exposure to bithionol. For both species, bithionol was determined to be toxic at 25 and 35 mg L −1 exhibiting median lethal times (LT50s) ranging from 21 to 84 min. Morbidity occurred in the 5 and 10 mg L −1 treatments, however, due to sampling regime there were not enough fish available to calculate LT50s. Only bithionol at 1 mg L −1 was considered non-toxic with no signs of morbidity. Bithionol was more toxic in seawater than freshwater and had no acute effects on gill Na +/K + ATPase and succinic dehydrogenase, or plasma osmolality and chloride concentration. Bithionol at 1 mg L −1 reduced percent lesioned gill filaments in Atlantic salmon and rainbow trout by 33 and 27%, respectively, compared to the seawater control. Similarly, numbers of amoeba were reduced by 33 and 43% for Atlantic salmon and rainbow trout, respectively, when compared to the seawater control. Furthermore, bithionol reduced percent lesioned gill filaments as much as did the current industry standard of freshwater. This study demonstrated that a 1 h seawater bath containing 1 mg L −1 bithionol could be an improvement to the current method of treatment for AGD-affected Atlantic salmon and rainbow trout.

Potassium kinetics and its relationship with ventilation during repeated bouts of exercise in women

The purpose of this study was to determine the electrolyte concentration changes in arterial plasma from high-intensity repeated bouts of cycling exercise in well-trained females and to determine the relationships between arterial plasma lactate, potassium (K+), bicarbonate (HCO3(-)), and pH with minute ventilation. Fourteen female subjects (mean age = 27 +/- 4 years; mean height = 170 +/- 7 cm; mean weight = 62 +/- 7 kg; maximal oxygen uptake = 50 +/- 6 ml/kg/min) were recruited to perform 3 x 5 min bouts of exercise at 236 +/- 27 W with 10 min recovery between each set. Minute ventilation, arterial plasma lactate, potassium, calcium, chloride, and sodium ion concentrations were measured a minute 0, 1, 2, 3, 4, 5 of each set and midway through recovery (21 sampling points total per subject). The results showed that the strongest relationship was between arterial plasma K+ concentration and minute ventilation (r2 = 0.91), and, that arterial plasma lactate mirrored both arterial plasma HCO3(-) and pH. In conclusion, this study demonstrates that women exhibit similar electrolyte responses as reported elsewhere in men, and support the idea that K+ may partly contribute to controlling ventilation during high-intensity exercise and recovery.