Comparison of fosinopril and hydrochlorothiazide in patients with mild to moderate hypertension

Seventeen patients with mild to moderate hypertension, as indicated by a diastolic blood pressure (DPB) of 95-115 mmHg (WHO I), were treated in a randomized, double-blind, parallel study, with either 5 mg of fosinopril, a new phosphinic acid-containing angiotensin converting enzyme (ACE) inhibitor, or 25 mg of hydrochlorothiazide administered orally once daily for 4 weeks after a 4- to 6-week run-in period of placebo. The doses were increased to 10 mg of fosinopril or 50 mg of hydrochlorothiazide if DBP remained above 95 mmHg. The blood pressure (BP) fell from 157 +/- 12/104 +/- 7 mmHg (mean value +/- SD) at the start of the study to 146 +/- 21/97 +/- 8 mmHg (P less than 0.02) after 4 weeks, and to 149 +/- 19/97 +/- 7 mmHg (P less than 0.02) after 8 weeks of fosinopril treatment (n = 8). In the hydrochlorothiazide-treated patients (n = 9), BP fell from 153 +/- 9/105 +/- 5 mmHg at the start of the study to 140 +/- 11/97 +/- 7 mmHg (P less than 0.01) after 4 weeks, and to 131 +/- 11/94 +/- 7 mmHg (P less than 0.01) after 8 weeks. After the first dose, DBP fell from 102 to 99 mmHg (NS) in fosinopril-treated patients, and from 105 to 96 mmHg (P less than 0.02) in hydrochlorothiazide-treated subjects. Serum active fosinoprilate concentration increased to 5.6 ng ml-1, 25.9 ng ml-1, and 43.8 ng ml-1 after 30, 60 and 120 min, respectively, and remained at a level of 6.6-7.7 ng ml-1 after 4 and 8 weeks, respectively. Serum ACE activity decreased from 21.6 +/- 11.0 mumol min-1 l-1 at the start to 9.3 +/- 13.7, 4.4 +/- 4.6, and 2.9 +/- 2.8 mumol min-1 l-1 after 30, 60 and 120 min, respectively. No side-effects and no changes in blood counts, electrolytes or kidney function were attributed to fosinopril during the study. Fosinopril is a safe, long-acting antihypertensive drug with a smooth onset of action. Hydrochlorothiazide treatment caused potassium loss and an increase in the levels of uric acid and triglycerides. Diastolic blood pressure decreased to the same extent as a result of treatment with either drug, while systolic blood pressure was better controlled by hydrochlorothiazide.

Cardiac tamponade due to ovarian carcinoma

We describe a patient with ovarian carcinoma who presented with cardiac tamponade with subsequently development of cardiac arrest as the initial symptom. After successful resuscitation and pericardiocentesis our patient was given an intrapericardial infusion of bleomycin and there was no recurrence of pericardial effusion at 14 months follow-up.

Effects of licorice on plasma atrial natriuretic peptide in healthy volunteers

Ingestion of licorice, 100 g daily for 8 weeks, caused a rise in 81% in plasma atrial natriuretic peptide (ANP) concentration in 12 healthy subjects. Mean body weight increment (1.6 kg) correlated with the increase in plasma ANP (r = 0.59; P less than 0.01). The plasma concentrations of antidiuretic hormone, aldosterone, and plasma renin activity decreased. All these hormonal effects, reflecting retention of sodium and fluid volume, were probably due to the known mineralocorticoid properties of licorice. Blood pressure increased transiently and two subjects developed reversible hypertension. The rise in plasma ANP concentration during ingestion of licorice may be considered a physiological response to prevent fluid retention and development of hypertension.

Peripheral blood lymphocyte subsets in radiologists exposed to ionizing radiation

To investigate whether low dose ionizing radiation caused perturbation of peripheral blood lymphocytes in radiology unit staff, the T-helper/suppressor ratio was examined in eight radiologists exposed to low dose radiation over a period of 6 to 27 years (mean 12 years). No significant difference was noted in the T-cell subsets between exposed radiologists and non-exposed control subjects. The effect of low dose ionizing radiation on peripheral blood lymphocyte subsets seems to be virtually negligible. Further, measurement of the T-helper/suppressor ratio is not a reliable way of demonstrating any damage to bone marrow caused by low dose ionizing radiation.

Renal transplant artery stenosis and percutaneous transluminal angioplasty

Ten patients with renal transplant artery stenosis were treated with percutaneous transluminal angioplasty (PTA). All patients suffered from hypertension refractory to drug treatment. PTA was successful in five patients. Blood pressure improved significantly and the antihypertensive medication could be reduced or withdrawn. Acute angulation at the anastomosis prevented successful PTA in four patients. One inaccessible stenosis was corrected surgically. No significant complications arose. If a renal transplant artery stenosis is haemodynamically significant, PTA should be considered the method of first choice for correction.

Renin-aldosterone axis in ethanol intoxication: effect of A II infusion

Plasma renin activity (PRA) is increased while plasma aldosterone is not, during moderate ethanol intoxication. To elucidate mechanisms behind this dissociation of renin-aldosterone nexus, six healthy males were given angiotensin II (4 ng kg-1 min-1) by i.v. infusion following ingestion of ethanol (1.2 g kg-1 body weight). Prior to angiotensin II (A II) infusion, PRA rose and plasma aldosterone declined. A II infusion caused a roughly 3-fold increase of plasma aldosterone both in ethanol intoxication and in control experiments, and a transient suppression of PRA. Plasma renin substrate, cortisol, and angiotensin converting enzyme (ACE) remained unchanged. The decrease of serum potassium or the rise of Na+/K+ ratio in ethanol intoxication may explain the failure of the adrenal cortex to respond with aldosterone release to endogenous angiotensin II. However, the pressor dose of A II infused obviously overcame the blunting effect of ethanol on aldosterone release previously reported by us. Blood pressure, both diastolic and systolic, increased similarly during ethanol and control experiments in response to A II infusion, except in one subject, who during ethanol intoxication experienced a paradoxical fall in blood pressure while reacting normally to A II infusion without ethanol.

Inhibitor binding assay of rat serum angiotensin converting enzyme

Based on a specific binding of labelled inhibitor to the enzyme active centre, a new principle of enzyme assay, inhibitor binding assay (IBA), was developed and applied to measurement of rat serum angiotensin converting enzyme (ACE). Serum diluted 1:50 was incubated with 125I-labelled ACE inhibitor, 351A, at pH 7.0, 37 degrees C, for 2 h. Inhibitor bound to ACE was separated with coated charcoal and results were calculated from a standard curve. The advantages offered by the novel inhibitor binding assay include simplicity, specificity, absence of interference by other enzymes or immunological cross-reactions, and great sensitivity enabling measurement of ACE in concentrations less than 0.1 units/ml. This principle of enzyme assay will not only have potential new applications for research involving ACE but may also be extended to other enzymes.

Tissue distribution of angiotensin converting enzyme in the rat: effect of captopril treatment

Effect on different tissues with regard to angiotensin converting enzyme during captopril treatment in the rat was studied. Male Wistar-Kyoto rats (n = 9) were treated during four weeks with captopril dissolved into the drinking water at the dose 30 mg/kg/day. Control rats (n = 9) had water only. Serum angiotensin converting enzyme (ACE) activity increased three-fold during captopril treatment, and ACE of purified pulmonary plasma membranes increased about 64% (P less than 0.001) compared to untreated rats. ACE activity of membrane fractions of other tissues studied i.e. testicles, epididymes, kidneys, and small intestine brush border did not increase similarly during captopril treatment. The highest amounts of ACE was demonstrated in epididymes, but captopril did not produce increased amounts of ACE in the epididymes. The main source of increased serum ACE activity during captopril treatment appeared to be in the pulmonary tissue.

Two different primary lung malignancies after a successful kidney transplantation

A patient with two histologically different primary pulmonary malignancies occurring simultaneously ten months after a successful cadaveric renal transplantation is reported. One tumor was an adenocarcinoma of the left lung and the other an oat cell carcinoma of the right lung. The differentiation of the two tumors was made by a fluorescein-conjugated antikeratin antibody staining technique. No tumor was present at the time of transplantation as judged from chest examinations. Ten months after transplantation a left-sided pleural effusion caused by the adenocarcinoma occurred simultaneously with a small infiltrate in the apex of the right lung. Simultaneous development of two histologically different lung tumors is unusual, and even more rare after renal transplantation.

Cardiac failure, hepatic congestion and increased level of serum carcinoembryonic antigen

A 65-year-old woman undergoing chronic haemodialysis for chronic nephritis had transiently elevated serum carcinoembryonic antigen levels, up to 26 ng/ml for nearly 3 months. This elevation was most probably due to cardiac failure with hepatic congestion and pulmonary oedema, because the antigen level returned to normal when the cardiac failure was properly treated, and comprehensive examinations revealed no other cause. During follow-up for 18 months, the carcinoembryonic antigen level has remained normal.

Regulation of angiotensin converting enzyme

Angiotensin converting enzyme (ACE;EC 3.4.15.1), or kininase II, was studied in serum, cultured endothelial cells from cord artery, in macrophages of humans, and in serum and purified plasma membranes of rats following treatment with inducers of ACE biosynthesis. ACE activity was measured in biological fluids with an enzyme kinetic method employing synthetic 1-hipp-1-his-l-leu tripeptide as a substrate, and with a new method using 125I-labelled specific inhibitor of ACE as a sensitive probe for ACE binding sites. The latter technique also proved suitable for the quantification of ACE in cells. Anti-human ACE antibody was employed for immunofluorescence studies in human cells. Dexamethasone treatment caused an increase in ACE in cultured human endothelial cells, macrophages and in rat pulmonary plasma membranes, but failed to increase serum ACE activity in rats. Captopril and enalapril treatment of hypertensive patients increased total serum ACE, the increase being evident after removal of the active drug from the serum by prolonged storage or chloramine T treatment (captopril) or by dialysis (enalapril). Captopril increased the ACE content of endothelial cells and macrophages. Macrophages appeared sensitive to captopril induction of ACE biosynthesis after pre-stimulation with Escherichia coli lipopolysaccharide. Dexamethasone treatment potentiated the known induction of ACE in rat pulmonary tissue. Thus ACE biosynthesis may be enhanced by three categories of treatment: (1) glucocorticoid; (2) macrophage activation; (3) ACE inhibitors. The precise mechanism of ACE induction and its possible biological relevance await further clarification.

Decrease of serum angiotensin converting enzyme activity after discontinuation of captopril treatment

Serum ACE activity increased as expected about three-fold following six weeks of captopril (30 mg/kg/day) treatment in Wistar rats (n = 9). The effect on serum and lung ACE activity and concentration, respectively, was studied after captopril discontinuation. Serum ACE activity was measured at start and 3, 6, and 12 days after captopril withdrawal. The approximal half-life of serum ACE activity was 72 hours as judged from the decrease rate after stimulated ACE biosynthesis induced by captopril. No differences in lung plasma membranes and lung homogenate ACE concentrations between treated and untreated rats were observed 12 days after discontinuation of captopril treatment. Serum ACE activity remained unchanged in the control rats (n = 9). We conclude that induction of ACE biosynthesis in the rat is reversible after withdrawal of captopril.

Effect of time and dose on angiotensin converting enzyme during captopril treatment in the rat

The effect of treatment time and dose of captopril with regard to angiotensin converting enzyme (ACE) in serum, lungs and kidneys of the rat were studied. Normotensive Wistar rats were treated with a constant dose of captopril (0.2 mg/ml) during various time periods. In a second study rats were treated with different captopril doses (6.25 micrograms, 12.5 micrograms, 25 micrograms, 50 micrograms, and 200 micrograms/ml water) during three weeks. Serum ACE activity and pulmonary and kidney plasma membrane ACE concentrations were measured in both studies. Captopril treatment resulted in a rapid decrease of ACE in pulmonary and kidney plasma membranes and a simultaneously increase of serum ACE activity during the first day of treatment. This was followed by increased membrane concentrations of ACE in the lungs and return to normal ACE concentrations in membranes of kidneys, presumably due to increased ACE biosynthesis. Serum ACE activity continued to increase during the whole study. Serum ACE activity increased in a dose dependent manner during treatment with different captopril doses. Increased plasma membrane ACE concentrations were not observed in the rats treated with captopril at doses below 200 micrograms/ml water.

The induction of angiotensin converting enzyme by its inhibitors

The inhibitors of angiotensin converting enzyme (ACE), captopril and enalapril, were found to increase ACE concentration in cultured human endothelial cells from cord artery as measured with a novel ACE assay employing MK 351A, an inhibitor of ACE, and with immunofluorescense labeling using anti-human lung ACE antibody. Dexamethasone (10 nM) also increased ACE and potentiated the increase of cellular ACE caused by captopril. Similar effects of ACE inhibitors were seen in cultured human macrophages, particularly after prestimulation with E. coli lipopolysaccharide. In Wistar Kyoto rats, captopril caused a 3-fold increase of serum ACE, while dexamethasone (40 ug/day, 14 days) did not increase serum ACE. Combined treatment with captopril and dexamethasone caused a 5-fold increase of ACE in purified lung plasma membranes. ACE inhibitors induce increased ACE biosynthesis in endothelial cells, and in macrophages. The rise of cellular ACE with ACE inhibitors is potentiated by glucocorticoid.

Ultrasonic scanning after percutaneous renal biopsy

Renal ultrasonic scanning was performed before and after 57 consecutive kidney biopsies in order to assess the value of this method in the diagnosis of complications. One large and six small perirenal haematomas were found, corresponding to an incidence of 13%. This figure is considerably larger than the incidence found with conventional diagnostic methods, but smaller than with computed tomography. One hydronephrosis and a blood clot in the urinary bladder were also diagnosed. No clinically significant complications were missed. We recommend ultrasonography as the first diagnostic procedure when biopsy complications are suspected.

Induction of angiotensin-converting enzyme with the ACE inhibitory compound MK-421 in rat lung

Having observed that treatment of rats with captopril led to an increased ACE activity in serum and ACE concentration in lungs, we treated female Wistar Kyoto rats for 7 days with the esterified ACE inhibitor, MK-421 (1.0 mg/kg body weight per day), administered by Alzet osmotic minipump. Serum ACE activity decreased by 67% during MK-421 treatment when measured in non-dialyzed serum samples. Removal of the drug by dialysis unmasked a 280% increase of serum ACE activity. ACE concentration of crude lung homogenate increased 134% in MK-421-treated rats and ACE concentration in purified pulmonary plasma membranes increased by 34%. The increase of serum and lung ACE in MK-421-treated rats was similar to that seen in rats treated with captopril, and was probably due to induction of ACE biosynthesis. The mechanisms of this induction are unknown.

Induction of angiotensin I-converting enzyme in rat lung with captopril: the effect of adrenalectomy

In spontaneously hypertensive rats, treatment with captopril, 0.2 g/liter of drinking fluid for 12 to 24 weeks, caused a threefold increase in serum angiotensin I-converting enzyme activity. Angiotensin I-converting enzyme increased 25 to 120 percent in lung plasma membranes. The elution profile of angiotensin I-converting enzyme on DEAE cellulose and after gel filtration on Sepharose 4B was unchanged by captopril. The Km value value also remained unchanged. In Wistar rats subjected to bilateral adrenalectomy, treatment with the same dose of captopril for 3 days resulted in increased serum angiotensin I-converting enzyme activity in both sham-operated and adrenalectomized rats, but angiotensin I-converting enzyme concentration increased in lung plasma membranes from sham-operated rats and captopril-treated rats only. We conclude that captopril causes induction of angiotensin-converting enzyme biosynthesis in spontaneously hypertensive and Wistar rats. The change is a quantitative one. Intact adrenal glands may be important for the incorporation of angiotensin I-converting enzyme into lung membranes.

Dissociation of the effect of captopril on blood pressure and angiotensin converting enzyme in serum and lungs of spontaneously hypertensive rats

Spontaneously hypertensive rats (SHR) of the Okamoto-Aoki strain (n = 40) were treated with captopril (SQ 14,225; D-3-mercapto-2-methylpropanoyl-L-proline) orally, dose 0.2 mg/ml in drinking water. The treatment was initiated early and later during the course of developing hypertension. Continuously treated rats did not develop hypertension. Rats receiving captopril for 12 weeks remained normotensive, whereas withdrawal of the drug resulted in hypertension. Captopril treatment was effective in the rats with established hypertension and decreased the blood pressures to nearly normal values. Serum angiotensin converting enzyme (ACE) activity rose 3-fold in captopril treated rats. ACE in lung plasma membranes increased during captopril treatment, indicating that captopril induced biosynthesis of pulmonary ACE. No qualitative differences were found in the ACE from treated and not treated animals. The dissociation of the antihypertensive effect of captopril and of increased ACE activity in serum and lungs reduce the value of relating blood pressure effects of the drug to measured enzyme activity in the SHR.

Induction of angiotensin I-converting enzyme rat lung with Captopril (SQ 14225)

Angiotensin I-converting enzyme (ACE, EC 2.4.15.1.) was measured in serum and in pulmonary plasma membranes of 40 spontaneously hypertensive rats (SHR, Okamoto Aoki strain), divided into 4 groups, and treated with SQ 14225 (Captopril), 0.2 mg . ml-1 in drinking water, for 0-24 weeks. Serum ACE activity increased 2.5-3 fold after 12-24 weeks of SQ 14225 treatment, paralleled by an increase of ACE concentration in purified pulmonary plasma membranes (25-52%), and in ACE concentration upon solubilization with Triton X-100 from such plasma membranes (96-120%). We conclude that the ACE inhibitor, SQ 14225, causes marked induction of pulmonary ACE biosynthesis. High serum ACE activity probably reflects increased total biosynthesis of the enzyme.

Kidney transplantation and tumours

During the period 1964--1978 700 renal transplants were given to 602 patients. Eight patients had a history of tumour before transplantation. After transplantation six cases with a de novo tumour were found. The treatment of the pretransplant tumours was completed on average 3 years before transplantation. The average interval from transplantation to discovery of de novo tumour was 2 years. The pretransplant tumours appeared 5 to 9 years before last control (Jan. 79) (mean 8 years). Two of the transplanted patients with previous tumours died later of their tumours. The others are still alive. Two of the patients with de novo tumour died of vascular accidents and one of tumour. The other three are alive. It seems that transplantation can be successful in patients with previous tumours. This study does not support previous reports of increased risk of de novo tumours in transplanted patients.