Transport of nutrients and electrolytes across the intestinal wall in pigs

In recent years, intestinal transport processes have been studied in detail regarding both, functional and structural aspects. For monosaccharides different systems have been demonstrated for apical uptake: this includes the high-affinity SGLT1 as a distinct d-glucose system and GLUT5 for fructose. Specifically in pigs a low affinity, high-capacity system for d-glucose and d-mannose with no preference for Na⁺ over K⁺ and a very low affinity system are suggested as further uptake systems. As in other species, basolateral extrusion is mediated by GLUT2. The distributions of monosaccharide transport along the gastrointestinal axis as well as the potential role of paracellular monosaccharide absorption have not yet been clarified.

Amino acids can principally be absorbed by the paracellular and transcellular pathway whereas transcellular transport can either be mediated by facilitated diffusion or secondary active Na⁺-coupled transport. This includes different transport systems for neutral, anionic and cationic acids. In addition, the presence of the di-/tripeptides transport system PEPT1 which depends on an inwardly directed H⁺-gradient has also been confirmed for the pig small intestine, its quantitative proportion is still under debate.

Short chain fatty acids (SCFA) are the major end products of microbial carbohydrate fermentation which occurs along the gastrointestinal tract with the highest production rates in the large intestines. At least two uptake mechanisms have to be assumed, i.e., non-ionic diffusion and anionic exchange via SCFA⁻/HCO₃⁻-exchange. Controversial views still exist to what extent SCFA are metabolized within the epithelial tissue.

Segmental differences between small and large intestines have been demonstrated for Na⁺ absorption. Whereas in the small intestines the major part of Na⁺ absorption is mediated by coupled nutrient transport systems, aldosterone sensitive Na⁺ channels and Na⁺/H⁺-exchange are the dominant mechanisms in the hindgut. For Cl⁻ paracellular transport and anionic Cl⁻/HCO₃⁻-exchange are the major absorptive mechanisms. Cl⁻ secretion is mediated by apical channels which may be activated by toxins of different origin. Different types of Cl⁻ channels have been identified, such as Cystic Fibrosis Transmembrane Regulator (CFTR), Ca-activated Cl⁻ channels (CLCA) and Outwardly Rectifying Cl⁻ Channels (ORCC). Whereas CFTR has clearly been shown for jejunal and colonic epithelial and goblet cells controversy still exists on the relevance of CLCA and ORCC in pigs.

For Ca²⁺ there is evidence that both recently published channels TRPV5 and TRPV6 are also expressed in pig intestinal tissues, however, this has not yet been shown on protein level. From several functional approaches it was demonstrated that phosphate uptake can be mediated by both, a Na⁺-dependent transcellular component and paracellularly. On a molecular basis it is uncertain whether the transport protein of transcellular mechanism belongs to the NaPi-IIb cotransporter family.     

Cardiac arrhythmias and electrolyte disturbances in colic horses

Background

Despite increased focus on cardiac arrhythmias in horses, the nature and prevalence is still poorly described. Case reports suggest that arrhythmias occurring secondary to systemic disease are seen more commonly in the clinic than arrhythmias caused by cardiac disease. The aim of this study was to investigate the prevalence of arrhythmias in colic horses referred for hospital treatment. Associations between electrolyte disturbances and arrhythmias were also investigated.The study population consisted of eight control horses and 22 referred colic horses. A Holter electrocardiography (ECG) was recorded during the first 24 hours of admission. The ECG’s were analysed by a software program followed by manual visual inspection. Arrhythmias registered included second degree atrioventricular (AV) blocks, supraventricular premature complexes (SVPCs), and ventricular premature complexes (VPCs). Blood was collected at admission and again between 12 and 24 hours after ECG was applied, and analysed for concentrations of potassium, sodium, ionised calcium, chloride, glucose, and L-lactate.

Results

Heart rate was 37.4 ± 3.7 bpm in the control group, and 51.6 ± 11.8 bpm, in the colic group, which was significantly different (P < 0.0001). AV blocks and SVPCs were found in both groups, however only colic horses showed VPCs. No significant difference between the two groups was found for AV blocks, SVPCs, and VPCs (P = 0.08 - 0.76). The mean levels of potassium, sodium, ionized calcium, and chloride were significantly lower in the colic group compared to the control group at admission. Mean levels of glucose and L-lactate were significantly elevated in the colic group (P < 0.05).

Conclusions

This study describes prevalence of cardiac arrhythmias and electrolytes concentrations in colic horses compared to healthy controls. Although we only observed VPCs in the colic horses, no significant differences between colic horses and controls were found. Despite the colic horses having electrolyte changes at admission no correlation was found between the electrolyte disturbances and cardiac arrhythmias. Although no clear conclusions can be drawn from the present study, the results indicate that relatively mild colic per se is not pro-arrhythmogenic, whereas severe colic probably are more likely to result in ventricular arrhythmia.     

Physiological Changes in Mink (Mustela vison) Dams Subjected to Weaning at Different Times during Lactation

The influence of time of weaning on weight changes, and on hormone and electrolyte status in domestic mink (Mustela vison) dams raising at least five kits per litter was examined. The kits were weaned at either day 42 (group 1) or day 49 (group 2) after birth. The dams were weighed and urine and blood were sampled from day 29 to day 56 after delivery. A considerable loss of dams' body weight, constituting 6.3% in group 1 and 8.1% in group 2, was noticed on the day after weaning, indicating a greatly reduced food consumption on the day of weaning. No changes in plasma aldosterone and no significant decrease in urinary sodium concentration were seen in dams after removal from their litters, whereas, irrespective of time of weaning, urinary sodium and chloride concentrations were halved a few days after weaning compared with the other group. The plasma cortisol concentration was high before and during weaning and was nearly halved 1 week after weaning, implying less strain on the dams after weaning. It is concluded that the weaning period is a most vulnerable and stressful period to the dams irrespective of the actual time of weaning.     

Quality Control of Compounded Crystalloid Fluids for Intravenous Delivery to Horses

Background

Periodic lack of availability and high cost of commercially produced isotonic fluids for intravenous (IV) use in horses have increasingly led to use of home‐made or commercially compound fluids by veterinarians. Data regarding the quality control and safety of compounded fluids would be of benefit to equine veterinarians.

Objectives

To compare electrolyte concentrations, sterility, and endotoxin contamination of commercially available fluids to 2 forms of compounded isotonic crystalloid fluids intended for IV use in horses.

Methods

Prospective study. Two methods of preparing compounded crystalloids formulated to replicate commercial Plasma‐Lyte A (Abbott, Chicago, IL) were compared. One formulation was prepared by a hand‐mixed method involving chlorinated drinking water commonly employed by equine practitioners, and the other was prepared by means of ingredients obtained from a commercial compounding pharmacy. The variables for comparison were electrolyte concentrations, sterility, and presence of endotoxin contamination.

Results

Electrolyte concentrations were consistent within each product but different between types of fluids (P < 0.0001). Hand‐mixed fluids had significantly more bacterial contamination compared to commercial Plasma‐Lyte A (P = 0.0014). One of the hand‐mixed fluid samples had detectable endotoxin contamination.

Conclusions and Clinical Importance

Chlorinated drinking water is not an acceptable source of water to compound isotonic fluids for IV administration. Equine practitioners should be aware of this risk and obtain the informed consent of their clients.     

Effects of monopolar electrocoagulation on electrolytes and uterine ultrastructure in patients with laparoscopically hysterectomy

AIM: To investigate the effects of monopolar electrocoagulation on the changes of electrolytes and uterine ultrastructure in the patients with laparoscopically hysterectomy.METHODS: Sixty patients, who accepted laparoscopically hysterectomy in the Third Affiliated Hospital of Jinan University from December 2009 to December 2010,were selected in the study and divided into 2 groups by the different hemostasis methods.Thirty patients were in monopolar electrocoagulation group and another 30 patients were in Ligasure group.the plasma concentrations of electrolytes (potassium, sodium, chlorine and calcium) were measured before operation, during operation, 24 h and 48 h after operation.The uteruses from 5 patients in each group were collected and the dissections between uterine horn and fallopian tube were prepared for observations under light microscope and transmission electron microscope.RESULTS: Compared to the levels before operation, the concentrations of plasm potassium in all patients were increased during operation,and the plasm sodium was not changed due to the supplement during and after operation, but the plasm chlorine and calcium were decreased.The electrolyte levels came to normal 24 h and 48 h after operation.Comparing the difference between 2 groups, no statistical significance of electrolyte concentrations was observed.Under transmission electron microscope, breakage of the cell membrane, expansion of mitochondria, pyknosis of chromation and karyorrhexis were also observed.CONCLUSION: The pathological changes exist under transmission electron microscope, although no change of the tissues in the place 10 mm far away from monopolar electrocoagulation is found under light microscope.     

Diel pattern of haematocrit, serum metabolites, osmotic pressure, electrolytes and thyroid hormones in sea bass and sea bream

The diel pattern of haematocrit, serum metabolites, electrolytes and thyroid hormones are described in sea bass, Dicentrarchus labrax, and sea bream, Sparus auratus, held under 12L:12D light cycle (0600–1800 h light). No diel rhythmicity in haematocrit, total proteins, potassium and chloride was observed. Maximum values of glucose, osmotic pressure and sodium were recorded at dusk (1800 h) in both species, irrespective of differences in the size of fish and feeding regime used. Maximum and minimum triiodothyronine values were found during the scotophase in bass and during the photophase in bream. Maximum thyroxine levels occurred at 1400 h (bass) and 1800 h (bream) and minimum during the scotophase, in both species. The light/dark alternation seems to be an important synchronizer of the observed diel changes. Results are discussed in relation to the timing of feeding and the general activity of the fish.     

Blood values of juvenile northern elephant seals (Mirounga angustirostris) obtained using a portable clinical analyzer

Background — Sick, injured, or orphaned juvenile northern elephant seals ( Mirounga angustisrostris ) treated at rehabilitation centers frequently present with abnormalities in blood sodium, potassium, chloride, BUN, and glucose concentrations, and HCT. These abnormalities could be detected rapidly using a portable blood analyzer, but the results with this analysis method do not necessarily equate with those obtained using other techniques.
Objective — The objective of this study was to better assess the clinical relevance of blood values obtained from a portable analyzer and to compare the results with values obtained using more common methods of analysis.
Methods — Heparinized whole blood samples were collected from 20 rehabilitated juvenile northern elephant seals. A portable clinical analyzer (i-STAT, i-STAT Corp, East Windsor, NJ, USA) was used to establish baseline values. Serum biochemical values were obtained using an automated chemistry analyzer (Olympus AU5200, Olympus America, Melville, NY, USA). HCT was determined using EDTA whole blood and a cell counter.
Results — Using the portable analyzer, mean (minimum-maximum) values were obtained for sodium, 143 (132–146) mmol/L; potassium, 4.4 (3.9–5.8) mmol/L; chloride, 106 (101–109) mmol/L; BUN, 1.8 (1.1–2.4) mmol/L; glucose, 7.55 (5.99–8.49) mmol/L; and HCT, 0.55 (0.52–0.61) L/L. Average differences between methods were small for potassium (-0.45 mmol/L), BUN (0.1 mmol/L), and HCT (0.037 L/L) but were large for sodium (-6.8 mmol/L), chloride (-6.4 mmol/L), and glucose (-0.56 mmol/L).
Conclusions — These results suggest that the i-STAT portable analyzer could be useful for clinically assessing juvenile elephant seals. However, when making medical decisions, the clinician should be aware of differences associated with various analyzers and sample types.