Severe hyponatraemia. A study of 17 patients

17 patients with severe hyponatraemia (none had cardiac failure or had lately had an operation) all had excessively high plasma-antidiuretic hormone (A.D.H.). Only 13 had features typical of the syndrome of inappropriate secretion of A.D.H. (S.I.A.D.H.). Plasma-A.D.H. was not related to either plasma-sodium or diagnosis. There were as many patients with chest infection as with carcinoma of the lung. Plasma-sodium and plasma-A.D.H. returned rapidly towards normal in the patients with chest infection or volume depletion but these concentrations corrected much more slowly in patients with carcinoma of the lung. The increase in plasma-sodium in patients with chest infection was too rapid to be produced by water-deprivation treatment and was due to return of plasma-A.D.H. to normal. The term S.I.A.D.H. implies an understanding of pathophysiology that does not exist. As a diagnosis it does not help in management or prognosis. A simpler, more descriptive terminology such as "hyponatraemia with carcinoma of the lung" would be more useful and less confusing in the clinical situation.

Sodium losing renal disease: Two cases and a review of the literature

Two patients with sodium-losing renal disease were studied in detail. Both presented with shock and hypotension which was attributed at first to other causes, as was the recurrent hyponatraemia in one of them. In both patients the cause of the sodium loss was probably unrelieved urinary obstruction which has been reported previously to cause water loss but not sodium loss. Both patients had severe hyponatraemia when they were sodium depleted, which has previously been attributed to water retention from excessive secretion of antidiuretic hormone. Plasma arginine vasopressin concentrations were raised in one patient but not in the other. The cause of the water retention in the other patient is not known. One of the patients, like others described in the literature, was only able to vary his sodium excretion within narrow limits. He became sodium depleted on a normal intake and oedematous when he was given saline intravenously. We suggest that the term sodium-losing renal disease should be replaced by the term 'fixed sodium' excretion renal disease.

Treatment of Bartter's syndrome in early childhood with prostaglandin synthetase inhibitors

The diagnosis of Bartter's syndrome was made in a 9-month-old boy investigated for poor weight and height gain. Initial treatment with oral potassium supplements and later spironolactone had little or no effect on his growth, although plasma potassium rose to normal after spironolactone. At 33 months indomethacin therapy was started with dramatic results. His symptoms went and his height and weight accelerated into the normal range. In view of the toxicity of indomethacin it was replaced after 12 months by another prostaglandin synthetase inhibitor, ketoprofen, with a satisfactory result. During the change-over period from indomethacin to ketoprofen the expected deterioration in clinical well-being was observed, accompanied by a rise in urinary prostaglandins and plasma renin activity. Prostaglandin synthetase inhibitors provide the best available treatment for Bartter's syndrome.

Renin and aldosterone relationships in manic depressive psychosis

The paper describes a two-month period of study in four bipolar manic-depressive patients in a metabolic ward. Plasma renin activity, packed cell volume, plasma sodium and potassium were determined at intervals. Twenty-four-hour urinary sodium, potassium and creatinine were also estimated daily. Aldosterone production rate was measured on two occasions for each patient. Three of the patients showed at least one episode each of mania and depression during the study, while the fourth patient, who was receiving prophylactic lithium throughout, had one ten-day depressive episode but was otherwise normal. No obvious relationship between mood and plasma renin activity was observed, but the group showed a high resting renin activity, a blunted renin response to posture, and inappropriate aldosterone production rates for the renin activity found. It is postulated that a primary defect in the aldosterone-renin system may be present in bipolar manic-depressive psychosis.

Internal proteins of influenza virus: 35S-methionine peptide maps as genetic markers

Methods are described for the preparation in vivo of 35S-methionine-labelled influenza viruses, the purifiction of the nucleoprotein (NP) and matrix (M) proteins and the separation of peptides obtained by protease digestion by two-dimensional thin-layer chromatography. The maps of the M proteins of A/Okuda/57(H2N2) and A/Finland/4/74(H3N2) were very similar overall but differed in three peptides. Hence they could be clearly distinguished. Maps of the NP proteins of the same strains showed a greater number of differences. A recombinant strain having the haemagglutinin and neuraminidase of the A/Finland/4/74 parent and the virulence of the A/Okuda/57 parent was shown to have the M and P proteins of A/okuda/57.

Failure of saralasin to predict a response to surgery in renovascular hypertension

Arteriography in two patients with renovascular hypertension suggested fibromuscular hyperplasia, mainly affecting the right renal artery. When saralasin was infused intravenously there was no fall in blood-pressure in either patient. However, both had a raised renal-vein plasma-renin activity on the affected side, relative to the unaffected kidney. Auto-transplantation resulted in a sustained reduction in arterial pressure in both patients. A negative saralasin test should not necessarily exclude further investigation of young patients with severe hypertension.

The effect of carbidopa administration on urinary sodium excretion in man. Is dopamine an intrarenal natriuretic hormone?

1 Carbidopa, a known inhibitor of the peripheral conversion of dopa to dopamine, was given to six normal volunteers to examine the effect of interference with dopamine synthesis on urinary sodium excretion. 2 On the first day of administration, carbidopa caused a significant fall not only in urinary dopamine excretion (P less than 0.01) but also in urinary sodium excretion (P less than 0.05). 3 A highly significant correlation was also found between mean sodium excretion and mean dopamine excretion in the days prior to and during carbidopa administration (r = 0.617, P less than 0.001; 4 = 0.764, P less than 0.001 respectively). 4 The significance of these findings is discussed and it is proposed that dopamine may be an important intrarenal natriuretic hormone.

Evaluation of the rapid hippurate hydrolysis test with enterococcal group D streptococci

The rapid hippurate hydrolysis test was evaluated with the conventional test, using 17 group A streptococci, 9 non-enterococcal group D streptococci, 108 enterococcal group D streptococci, and 2 strains of Listeria monocytogenes. There was complete correlation between the rapid and conventional tests with all organisms except enterococcal group D. The rapid hippurate hydrolysis method was more sensitive with the enterococci; 95.4% were positive with the rapid method, and 9.3% were positive with the conventional method. Thin-layer chromatography (TLC) was performed on all isolates to determine if the end product of hydrolysis, glycine, was indeed present. The TLC results were in agreement with the rapid and conventional methods for group A streptococci, nonenterococcal group D streptococci, and L. monocytogenes. TLC results were in total agreement with the rapid hippurate hydrolysis test for the enterococcal group D isolates, thus verifying the accuracy of this more sensitive test. Trace amounts of glycine were found in the substrate, indicating the need for including an uninoculated substrate control as well as stock strains of group A and B beta-hemolytic streptococci (negative and positive controls, respectively) each time the rapid hippurate hydrolysis test is performed.

The specificity of antisera for the radioimmunoassay of arginine-vasopressin in human plasma and urine during water loading and dehydration

1. Rabbit antisera against arginine-vasopressin (AVP) were evaluated for sensitivity and specificity in a radioimmunoassay based on the extraction of AVP from plasma and urine on to Florisil. 2. Comparison of the immunoreactivity of AVP with analogues showed that one antiserum (R2) reacted principally with the hexapeptide ring and another (R4) bound to the tripeptide tail and was reactive with some reduction and hydrolytic products of the native peptide. 3. The minimum amount of AVP measurable in the radioimmunoassay was 1 pg. The extraction of AVP from plasma and urine gave a recovery of 93 per cent (sd 5 per cent). A plasma sample repeatedly assayed with R2 gave a value of 1.4 ng/1 (sd 0.2, n=12). 4. The antiserum specific for the hexapeptide ring (R2) showed that in normal subjects AVP concentration ranged from 3.2 +/- 2.52 ng/1 after dehydration to 0.16 +/- 0.1 ng/1 after water loading.

Autotransplantation of the kidney for fibromuscular dysplasia of the renal arteries

A young man was discovered to have symptomless hypertension, which subsequently proved to be caused by fibromuscular dysplasia of the renal arteries. Arterial disease was present on both sides but was more severe on the right. Samples of blood were obtained by selective catheterisation of each renal vein for the determination of plasma renin activity. The renal venous renin was greater on the right than on the left (ratio greater than 1-5 to 1) and secretion of renin by the left kidney was suppressed. Autotransplantation of the right kidney to the left internal iliac artery lowered the blood pressure at once and it has remained normal for 6 months. The implications of this procedure for the management of a bilateral disorder of the renal arteries, such as fibromuscular dysplasia, are discussed.

Brain tyrosine hydroxylase activity and systolic blood pressure in rats treated with either deoxycorticosterone and salt or angiotensin

The hypertension induced in adult male rats by doca/salt was found to be accompanied by a significant rise in whole brain tyrosine hydroxylase (TH) activity. A smaller hypertensive effect, produced by angiotensin (750 ng kg-1 daily) was also accompanied by a proportional rise in whole brain TH activity. The specific antagonists spironolactone and saralasin completely blocked both responses in the doca/salt- and angiotensin-treated animals respectively and spironolactone showed a partial inhibition of the effects of angiotensin. In all the animals treated there was a clear correlation between systolic blood pressure and whole brain TH activity. The significance of these changes is discussed in the light of the central mechanism of hypertension.

Renin release in the rabbit produced by ergometrine infusion

Intravenous ergometrine maleate (0·01 mg/kg/min) produced a significant rise of plasma renin activity in the rabbit.

These findings are discussed in relation to untoward reactions to the ergot alkaloids.