Changes In Electrolyte Balance Research Articles

Influence of “Sneznik-1/79” Mineral Water on Anthropometric, Functional and Biochemical Parameters of Professional Basketball Players: Role of Oxidative Stress

Abstract Adequate hydration represents the balance between the water intake and loss and has an unambiguous significance for public health and it is essential to sustain life. The changes in electrolyte balance which occur during and after training affect on athletes health and performance. Therefore, fluid replacement with adequate mineral composition is of utmost importance. The aim of the present study was to examine the influence of low mineral water from the well Sneznik-1/79 on anthropometric, functional, biochemical parameters and redox status of professional basketball players. In total, 17 male basketball players were included, during the pre-competitive mesocycle, and after the initial testing, they were randomly divided into two groups: group 1 - consumed the commercial drinking water for four weeks (n=7), and group 2 - consumed water from the well Sneznik-1/79 for four weeks (n=10). Determination of the anthropometric, functional, biochemical parameters and redox status was performed. Our results pointed out that consumption of mineral water from the well Sneznik is completely safe from the aspect of affecting various anthropometric, functional and biochemical parameters as well as systemic oxidative stress of professional athletes. In addition, existence of discretely better effects over commercial drinking water indicates that a long period of monitoring may certainly be of interest for further investigation.

120 Seasonal Variation of Select Serum Electrolyte Concentrations in Siberian Huskies Housed Outside in Ontario Canada from may Until October

Abstract The effect of season has been recognized in both human and veterinary medicine for its influence on various hematological and biochemical parameters. However, limited research has been conducted in dogs regarding seasonal electrolyte changes, especially in those non-exercising and housed outdoors. Therefore, the objective of this study was to evaluate the effects of seasonal variation in ambient conditions on electrolyte status in 28 outdoor-housed adult Siberian huskies (13 females: 8 spayed, 5 intact and 15 males: 9 neutered, 6 intact). Dogs had an average age of 5.3 ± 2.8 years and body weight of 23.22 ± 3.73 kg. Dogs were fed one of four dry extruded diets formulated with the same mineral premix. Fasted blood samples were collected monthly from May until October and sera were analyzed for Cl-, Na+, K+, Ca2+, Mg2+ and P using photometric analysis. Data were analyzed using PROC GLIMMIX of SAS with dog as a random effect and temperature, spay-neuter status, and age as fixed effects. Serum Na+, K+, Ca2+, and P concentration were least in May, and greatest in September, October, October, and June, respectively (P< 0.05). Conversely, serum Mg2+ were greatest in May and September, and least in August (P< 0.05). Serum Cl- were greatest in May and October, and least in July (P< 0.05). Across all months, females had decreased serum Ca2+ than males, intact dogs had greater serum Cl-, and younger dogs (<3 years of age) had greater serum P compared with older dogs (P< 0.05). These results suggest that dogs experience significant changes in electrolyte balance due to seasonal and ambient variation. Those that are higher risk for electrolyte loss and imbalance may benefit from supplementation during the summertime. Further research is needed to understand if seasonal or ambient variations drive these changes and if they compromise athletic performance.

Comparison Of Giving A Combination Of Red Ginger And Mint Leaves Booked With A Combination Of Lime And Honey On The Intensity Of Voting In Pregnant Women In Trimester I

Emesis gravidarum results in a decrease in appetite, this situation can cause changes in electrolyte balance with potassium, calcium and sodium which result in changes in body metabolism. Therefore, in reducing nausea and vomiting pregnant women should use complementary therapies that can be done easily at home. Pharmacological function is antiemetic (anti-vomiting). Lime has flavonoids, the flavonoid content is known to neutralize acidic digestive fluids, releasing toxins in the body. This study was conducted to determine the differences in the effectiveness of giving a combination of boiled red ginger and mint leaves and a combination of lime and honey on the intensity of nausea and vomiting in first trimester pregnant women. This study used a quasi-experimental research design with a pretest-posttest with control group design. Sampling by purposive sampling. The sample size was 28 pregnant women in the first trimester at the Cikande Public Health Center, Serang Regency. The research instrument is an observation sheet. Data analysis used Mann Whitney statistical test. The results of his research using the Mann Whitney statistical test showed a p-value of 0.498, this means that there is no significant difference in decreasing the intensity of nausea and vomiting in first trimester pregnant women at the Cikande Health Center, Serang Regency between those given boiled red ginger and mint leaves and a combination of lime. and honey for 4 days of treatment. It is hoped that health workers will provide education to pregnant women in traditional medicine or local wisdom.

Salivary Calcium Level and Its Correlation with Salivary pH, Salivary Volume, and Calcium Intake in Hypertensive Female Patients with Different Blood Sugar Levels.

This study aimed to evaluate the salivary calcium level and its correlation with salivary pH, salivary volume, and calcium intake in hypertensive female patients with different blood sugar levels. This cross-sectional study included 49 female subjects with hypertension. Subjects were divided into three groups based on the HbA1c test: normal, prediabetes, and diabetes. Unstimulated whole saliva was collected using the spitting method. Salivary calcium levels were evaluated using an Atomic Absorption Spectrophotometer. Salivary pH was obtained using a universal indicator pH paper test. Calcium intake was assessed by a semi-quantitative food frequency questionnaire. The Kruskal-Wallis test was used to compare salivary parameters and total calcium intake within study groups. Spearman rank correlation and multiple regression analysis were used to evaluate the correlation between salivary calcium levels and all variables in the study. No significant difference in salivary calcium, volume, pH, and total calcium intake was observed within the study groups. However, a significant correlation was found between salivary calcium levels and salivary pH in hypertensive females with normal blood glucose levels. Moreover, salivary calcium levels have a significant correlation with systolic blood pressure in prediabetes and diabetes groups. This study found a decrease in all salivary parameters (calcium, pH, and volume) as well as a low calcium intake in hypertensive females, despite no significant difference found in groups with different blood glucose levels. Blood glucose levels appeared to be a confounder in the relationship between salivary calcium with salivary pH and systolic blood pressure.

Literature Review: The Effectiveness of Giving Ginger (Zingiber Officinale Roscoe) to Pregnant Women Nausea Vomiting 1st Trimester Pregnancy

Nausea and vomiting often occur when you wake up in the morning, which is also called morning sickness. Nausea and vomiting that occur in the first trimester of pregnancy are caused by increased levels of the hormone Estrogen and Human Chorionic Gonadotropine (HCG) in serum from the placenta and can cause a decrease in appetite so that there is a change in electrolyte balance with potassium, calcium and sodium which causes changes in body metabolism. Nausea and vomiting during pregnancy affects about 80-90% of pregnant women. Ginger (Zingiber officinale Roscoe) is the most widely used herbal therapy in the management of nausea and vomiting. The purpose of this study was to determine how effectiveness ginger was in reducing the frequency of nuesea and vomiting in pregnant women in the 1st trimester.This study uses a literature study method obtained through electronic media with keywords. There were 8 selected articles, consisting of 5 international and 3 national articles. This article provides information about the effectiveness of giving ginger to reduce the frequency of nausea and vomiting in pregnant women in the 1st trimester. The conclusions obtained from the analysis are that ginger can reduce nausea and vomiting in pregnant women in the 1st trimester.

Literature Review: The Effectiveness of Giving Ginger (Zingiber Officinale Roscoe) to Pregnant Women Nausea Vomiting 1st Trimester Pregnancy

Nausea and vomiting often occur when you wake up in the morning, which is also called morning sickness. Nausea and vomiting that occur in the first trimester of pregnancy are caused by increased levels of the hormone Estrogen and Human Chorionic Gonadotropine (HCG) in serum from the placenta and can cause a decrease in appetite so that there is a change in electrolyte balance with potassium, calcium and sodium which causes changes in body metabolism. Nausea and vomiting during pregnancy affects about 80-90% of pregnant women. Ginger (Zingiber officinale Roscoe) is the most widely used herbal therapy in the management of nausea and vomiting. The purpose of this study was to determine how effectiveness ginger was in reducing the frequency of nuesea and vomiting in pregnant women in the 1st trimester.This study uses a literature study method obtained through electronic media with keywords. There were 8 selected articles, consisting of 5 international and 3 national articles. This article provides information about the effectiveness of giving ginger to reduce the frequency of nausea and vomiting in pregnant women in the 1st trimester. The conclusions obtained from the analysis are that ginger can reduce nausea and vomiting in pregnant women in the 1st trimester.

Vomiting of first pregnancy trimester: how to estimate?

Objective of the study: to study changes of electrolyte balance and hematocrit in the first trimester vomiting and in uncomplicated pregnancy.Material and methods. 109 women in the first trimester of pregnancy were divided into 2 groups. Group I consisted of 58 patients with complaints on vomiting from 1 to 10 times a day, group II – 51 women without complaints of nausea and vomiting. At the beginning of the study and at 20 weeks the concentrations of the main electrolytes in the serum, as well as the hematocrit index, were determined in all study participants. Groups were compared basing not only modern concentration level, but also distribution of each meaning in total.Results. Despite the loss of fluid and electrolytes with vomiting, patients in group I did not differ from women with uncomplicated pregnancy in average ion concentrations and hematocrit. However, the distribution of the study participants by the indicators showed that the majority of women in group II had high levels of serum sodium and hematocrit. In addition, the dynamics of pregnancy progression in women of group I showed a decrease in sodium concentration and in pregnant women in group II – on the contrary, the tendency to increase this indicator.Conclusion. Vomiting of the first trimester does not lead to significant changes in electrolyte balance. However, with the progression of pregnancy, such patients show adequate hemodilution, which implies a decrease in sodium concentration and hematocrit. At the same time, in some patients with uncomplicated course of the first trimester of pregnancy, there is a tendency for defective hemodilution. This can lead to endothelial dysfunction and associated obstetric complications, by the time patients with first pregnancy vomiting have more favorable changes of blood circulation

Role of opioid signaling in kidney damage during the development of salt-induced hypertension.

Opioid use is associated with predictors of poor cardiorenal outcomes. However, little is known about the direct impact of opioids on podocytes and renal function, especially in the context of hypertension and CKD. We hypothesize that stimulation of opioid receptors (ORs) contributes to dysregulation of intracellular calcium ([Ca2+]i) homeostasis in podocytes, thus aggravating the development of renal damage in hypertensive conditions. Herein, freshly isolated glomeruli from Dahl salt-sensitive (SS) rats and human kidneys, as well as immortalized human podocytes, were used to elucidate the contribution of specific ORs to calcium influx. Stimulation of κ-ORs, but not μ-ORs or δ-ORs, evoked a [Ca2+]i transient in podocytes, potentially through the activation of TRPC6 channels. κ-OR agonist BRL52537 was used to assess the long-term effect in SS rats fed a high-salt diet. Hypertensive rats chronically treated with BRL52537 exhibited [Ca2+]i overload in podocytes, nephrinuria, albuminuria, changes in electrolyte balance, and augmented blood pressure. These data demonstrate that the κ-OR/TRPC6 signaling directly influences podocyte calcium handling, provoking the development of kidney injury in the opioid-treated hypertensive cohort.

Influence of “Sneznik-1/79” Mineral Water on Anthropometric, Functional and Biochemical Parameters of Professional Basketball Players: Role of Oxidative Stress

AbstractAdequate hydration represents the balance between the water intake and loss and has an unambiguous significance for public health and it is essential to sustain life. The changes in electrolyte balance which occur during and after training affect on athletes health and performance. Therefore, fluid replacement with adequate mineral composition is of utmost importance. The aim of the present study was to examine the influence of low mineral water from the well Sneznik-1/79 on anthropometric, functional, biochemical parameters and redox status of professional basketball players. In total, 17 male basketball players were included, during the pre-competitive mesocycle, and after the initial testing, they were randomly divided into two groups: group 1 – consumed the commercial drinking water for four weeks (n = 7), and group 2 – consumed water from the well Sneznik-1/79 for four weeks (n = 10).Determination of the anthropometric, functional, biochemical parameters and redox status was performed. Our results pointed out that consumption of mineral water from the well Sneznik is completely safe from the aspect of affecting various anthropometric, functional and biochemical parameters as well as systemic oxidative stress of professional athletes. In addition, existence of discretely better effects over commercial drinking water indicates that a long period of monitoring may certainly be of interest for further investigation.

Corneal health and contact lens wear: Ion chromatography as an electrolyte probe

Purpose: Tear osmolarity and the concentrations of ocular electrolytes in the eye are known to influence corneal health. Similarly, corneal cells are known to be sensitive to changes in electrolyte balance. Ion transport through contact lenses can influence electrolyte equilibration between preand post-lens tear film. Until now no suitable technique has been identified to quantify these effects. This study utilised ion chromatography to examine multiple ion transport through lenses and the measurement of ex-vivo tear samples. Methods:AmodifiedDionex ion chromatographenabled simultaneous measurement of Na+/K+/Ca2+ and Mg2+ concentrations in both single (5 l) tear samples and lens/membrane permeation studies. In addition to commercial contact lenses, conventional HEMA membranes (40% water) and acrylamide-based corneal model hydrogel membranes (ca 90% water) were mounted in purpose-designed permeability cells and the transport of mixed electrolytes (e.g. 0.25M NaCl, KCl and CaCl2) measured. Results: In baseline studies, the relative ratio of the main tear cations measured in healthy tear film samples was found to be Na+:K+:Ca2+:Mg2+ =140:11:1.2:1. This accord with the observation that the range of K+ concentrations in tears (ca 15–30mM) is high and Ca2+ and Mg2+ concentrations (ca 0.4–0.8 and 0.5–1.1mM) is low, relative to serum. The relative permeability coefficients of lenses and membranes were consistent (i.e. NaCl <KCl » CaCl2) ranging between 141.2×10−7: 148.2×10−7: 98.2×10−7 cm2/s (±5% for 90% acrylamide based hydrogel) and 2.8×10−7:3.2×10−7:0.7×10−7 cm2/s (±5% for 40% HEMA hydrogel). Conclusions: Ion chromatography enables tear electrolytes to be accurately monitored in 5 l samples. This, coupled with tear envelope sampling, provides a means of correlating clinical signs and symptoms with post-lens electrolyte concentrations and the ion permeability coefficients of individual lenses. Anisa Mahomed completed an MEng in Chemical Engineering and then obtained her PhD from the Biomaterials Research Group at Aston University. Her thesis discussed the aspects of the fabrication of novel hydrogels for dermal and ocular applications. She is currently a postdoctoral researcher and her interests include investigating factors that affect the uptake, release and transport of various species from hydrogels and developing analytical techniques to enable the understanding of clinical adverse events related to the use multipurpose solutions.

Plasma protein influx in contact lens wear

Purpose: Tear osmolarity and the concentrations of ocular electrolytes in the eye are known to influence corneal health. Similarly, corneal cells are known to be sensitive to changes in electrolyte balance. Ion transport through contact lenses can influence electrolyte equilibration between preand post-lens tear film. Until now no suitable technique has been identified to quantify these effects. This study utilised ion chromatography to examine multiple ion transport through lenses and the measurement of ex-vivo tear samples. Methods:AmodifiedDionex ion chromatographenabled simultaneous measurement of Na+/K+/Ca2+ and Mg2+ concentrations in both single (5 l) tear samples and lens/membrane permeation studies. In addition to commercial contact lenses, conventional HEMA membranes (40% water) and acrylamide-based corneal model hydrogel membranes (ca 90% water) were mounted in purpose-designed permeability cells and the transport of mixed electrolytes (e.g. 0.25M NaCl, KCl and CaCl2) measured. Results: In baseline studies, the relative ratio of the main tear cations measured in healthy tear film samples was found to be Na+:K+:Ca2+:Mg2+ =140:11:1.2:1. This accord with the observation that the range of K+ concentrations in tears (ca 15–30mM) is high and Ca2+ and Mg2+ concentrations (ca 0.4–0.8 and 0.5–1.1mM) is low, relative to serum. The relative permeability coefficients of lenses and membranes were consistent (i.e. NaCl <KCl » CaCl2) ranging between 141.2×10−7: 148.2×10−7: 98.2×10−7 cm2/s (±5% for 90% acrylamide based hydrogel) and 2.8×10−7:3.2×10−7:0.7×10−7 cm2/s (±5% for 40% HEMA hydrogel). Conclusions: Ion chromatography enables tear electrolytes to be accurately monitored in 5 l samples. This, coupled with tear envelope sampling, provides a means of correlating clinical signs and symptoms with post-lens electrolyte concentrations and the ion permeability coefficients of individual lenses. Anisa Mahomed completed an MEng in Chemical Engineering and then obtained her PhD from the Biomaterials Research Group at Aston University. Her thesis discussed the aspects of the fabrication of novel hydrogels for dermal and ocular applications. She is currently a postdoctoral researcher and her interests include investigating factors that affect the uptake, release and transport of various species from hydrogels and developing analytical techniques to enable the understanding of clinical adverse events related to the use multipurpose solutions.

O104 Influence of the Long Interdialytic Break on the Incidence of Serious Arrhythmias and Sudden Cardiac Death in Patients with Chronic Kidney Disease (CKD) undergoing Haemodialysis

Introduction: Chronic kidney disease (CKD) patients on haemodialysis (HD) have a high risk of sudden cardiac death (SCD). Traditional SCD risk factors donot adequately explain this but a unique risk factor may be a longer interval between HD sessions (interdialytic period, IDP). Inherent in conventional HD (thrice-weekly) are two 48-hour (short) breaks and one 72-hour (long) break between the start of HD sessions. Changes in electrolyte balance, ventricular repolarization (VR) and autonomic tone (AT) may be more profound after the longer IDP. Objectives:We used an implantable loop recorder (ILR) to define the incidence and timing of significant arrhythmias in a HD population, comparing the impact of the long vs short IDP (event time distribution-ETD). We used Ambulatory 24-hour Holter monitoring to evaluate markers of arrhythmic risk according to ETD. Methods: 50 CKD patients undergoing thrice-weekly conventional HD were recruited & underwent ILR insertion with regular fortnightly device follow-up. Pts with left ventricular ejection fraction 16 beats <30sec) in 7 (14%). The combined primary end point occurred in 14 pts (28%) with 385/615 (63%) events occurring during the long IDP (p<0.001). No episodes of long QT related polymorphic VT were observed.

SYNDROME OF INTRACRANIAL HYPERTENSION (DISTENSION) IN CHILDREN

The syndrome of «intracranial hypertension» is often used in the daily practice of pediatricians and child neurologists. Unjustified establishment of this diagnosis leads to unnecessary prescriptions of diuretics, and it leads to complications (infringement of action of the kidneys, changes in electrolyte balance, etc.). The following diagnostic criteria of intracranial hypertension and distension are proposed: - Clinical symptoms: rapid increase in the size of the head, including a tension of prefontanel, and extension of the cranial sutures, frequent vomiting which is not related to food, restriction of the movement of the eyeballs upward and to the side, exophthalmia, convergent strabismus. These features should be confirmed by additional criteria. - Fundus examination: edema, swelling of the optic disc, expansion and tortuosity of the veins, the development of secondary atrophy of the optic nerve. - The results of sonography. - The results of CT- and MRI- examinations of the brain.

Balanced maintenance fluids in PICU are safe and cost effective

IntroductionThe use of hypotonic intravenous fluid in children is acknowledged as a cause of iatrogenic harm.1 Fatalities have been documented since 1992.2 In 2007 the National Patient Safety Agency (NPSA)...

Hydration and electrolyte balance in horses during an endurance season

Limited information exists about the physiological training-induced changes in electrolyte balance of horses competing in long distance endurance races. To determine the effects of endurance training and racing on hydration and electrolyte balance in horses. Blood and urine were sampled at rest in 8 endurance horses before training and after two 11 week training periods (T1 and T2). Each training was followed by a 120 km endurance ride and horses were sampled before, during and 2 h after the rides. Blood was analysed for packed cell volume (PCV), total protein (TP), urea, creatinine and electrolyte concentrations. Urine was analysed for pH, specific gravity, creatinine and electrolyte concentrations, which allowed calculation of fractional excretion of electrolytes (FE). Changes associated with training and with the rides were assessed using a Student paired t test (P ≤ 0.05). Plasma TP, urea, creatinine and sodium concentrations increased during T1 and PCV decreased significantly during T2. FE(Cl) increased during T1 then decreased. FE(K) increased significantly during both training periods. Other blood and urine parameters did not show remarkable changes with training. PCV, plasma TP, urea, creatinine and total Ca concentrations increased and plasma Na(+) and Cl(-) concentrations decreased during both rides. Urine concentrations of Na(+), K(+) and Cl(-), FE(Na) and FE(Cl) decreased during the rides while urinary creatinine increased. FE(K) increased during the first part of the rides then decreased. These data contribute to the understanding of changes associated with training and prolonged endurance exercise.

Exercise and Fluid Replacement

This Position Stand provides guidance on fluid replacement to sustain appropriate hydration of individuals performing physical activity. The goal of prehydrating is to start the activity euhydrated and with normal plasma electrolyte levels. Prehydrating with beverages, in addition to normal meals and fluid intake, should be initiated when needed at least several hours before the activity to enable fluid absorption and allow urine output to return to normal levels. The goal of drinking during exercise is to prevent excessive (>2% body weight loss from water deficit) dehydration and excessive changes in electrolyte balance to avert compromised performance. Because there is considerable variability in sweating rates and sweat electrolyte content between individuals, customized fluid replacement programs are recommended. Individual sweat rates can be estimated by measuring body weight before and after exercise. During exercise, consuming beverages containing electrolytes and carbohydrates can provide benefits over water alone under certain circumstances. After exercise, the goal is to replace any fluid electrolyte deficit. The speed with which rehydration is needed and the magnitude of fluid electrolyte deficits will determine if an aggressive replacement program is merited.

The Effect of Mitochondrial Heteroplasmy on Murine Physiology

The Effect of Mitochondrial Heteroplasmy on Murine Physiology

Beidseitige H�rminderung in der Gravidit�t

Neurological impairment during pregnancy is also commonly found in otorhinolaryngology. Cranial nerve palsy, e.g. of the facial nerve or changes in signal processing of the hearing system, are described. Apart from changes in electrolyte balance, these neurological alterations are attributed to hormone fluctuations. The spontaneous remission of the neurological problems after delivery is frequently reported. This case report presents a 34 year pregnant patient suffering from binaural sensorineural hearing loss and tinnitus in the third trimester. Three weeks after delivery there was a spontaneous remission and a measurable improvement of the audiological findings. Although treatment with cortisone and antibiotics remained without effect, a pharmacological treatment during pregnancy has to be carefully and individually coordinated. An interdisciplinary approach in diagnostic and therapeutic measures together with gynaecologists appears obligatory.

Regulation of rat adrenal vasoactive intestinal peptide content: effects of adrenocorticotropic hormone treatment and changes in dietary sodium intake.

Vasoactive intestinal peptide (VIP) is well established as a paracrine regulator of adrenal function. It is present in nerves supplying the adrenal cortex, although previous studies have found that the amount of VIP in the outer zones of the rat adrenal is not affected by ligating the splanchnic nerve supplying the adrenal gland. The present studies were designed to investigate the mechanisms involved in regulating the VIP content of the rat adrenal gland. This study examined the effects of changes in electrolyte balance and adrenocorticotropic hormone (ACTH) administration on the adrenal content of VIP as measured by radioimmunoassay. Rats on a low sodium diet had a significantly increased capsular/zona glomerulosa immunoreactive VIP (irVIP) level, while rats on a high sodium diet had suppressed levels relative to controls. Changes in dietary sodium did not affect inner zone/medullary VIP content. Administration of ACTH caused a decrease in irVIP levels in the capsular/zona glomerulosa portion of the adrenal gland but had no effect on the inner zone/medulla. Analysis of mRNA encoding VIP revealed a large increase in expression of VIP in the sodium-deplete group compared with the control, with no change in VIP expression in the sodium-loaded group. ACTH treatment was found to significantly decrease VIP mRNA levels in the capsular portion. Neither ACTH treatment nor changes in sodium intake affected inner zones/medullary VIP message. These data suggest that VIP in the capsule and zona glomerulosa region of the adrenal cortex is regulated in response to the physiological status of the animal, with changes in capsular/zona glomerulosa VIP correlating with changes in zona glomerulosa function.

Disorders of mineralocorticoid synthesis.

Abnormalities of mineralocorticoid synthesis and/or metabolism profoundly affect the regulation of electrolyte and water balance and of blood pressure. Characteristic changes in extracellular potassium, sodium and hydrogen ion concentrations are usually diagnostic. Serious deficiency may be acquired, for example in Addison's disease, or inherited. In most of the inherited syndromes, the precise molecular changes in specific steroidogenic enzymes have been identified. Mineralocorticoid excess may be caused by aldosterone or 11-deoxycorticosterone by inadequate conversion of cortisol to cortisone by 11beta-hydroxysteroid dehydrogenase type 2 in target tissues (see Chapter 4), by glucocorticoid receptor deficiency or by constitutive activation of renal sodium channels. Changes in electrolyte balance and renin as well as the abnormal pattern of corticosteroid metabolism are usually diagnostic. Where these abnormalities are inherited (e.g. 11beta- or l7alpha-hydroxylase deficiencies, glucocorticoid remediable hyperaldosteronism (GRA), receptor defects, Liddle's syndrome), the molecular basis is again usually known and, in some cases, may provide the simplest diagnostic tests. Primary aldosteronism, although readily identifiable, presents problems of differential diagnosis, important because optimal treatment is different for each variant. Moreover, the mechanisms by which the variants develop are poorly understood. Finally, a significant proportion of patients with essential hypertension show characteristics of mild mineralocorticoid excess, for example low renin levels. Is this relevant to pathophysiology and, if so, is the effect induced via classic mechanisms of action or through newly discovered direct actions on the brain, heart and blood vessels? These questions are the subject of current research.