Urinary excretion of endogenous digitalis-like natriuretic substances in healthy subjects. Effect of sodium load

In the current study digoxin-like immunoreactivity (DLIA), Na-K-ATPase inhibition and natriuretic activity of urinary extracts from 10 healthy volunteers following a low and a high-sodium intake, respectively, were measured. Detectable urinary DLIA (46.1 +/- 5.6 ng eq digoxin/day), Na-K-ATPase inhibition (182.9 +/- 22.7 nmol eq oub/day) and natriuretic activity (UNaV: 0.38 +/- 0.11 microEq/min) were observed during the low-sodium diet period in all subjects. High-sodium diet was associated with a significant increase in DLIA (87.9 +/- 9.2 ng eq digoxin/day, p less than 0.001) which parallelled changes in Na-K-ATPase inhibition (359.8 +/- 51.9 nmol eq oub/day, p less than 0.005) and natriuretic activity (UNaV: 1.33 +/- 0.3 microEq/min, p less than 0.025). These results support the contention that DLIA is related to NH.

[Changes in various hematologic parameters following treatment with zinc acetate]

The effect of different doses of zinc acetate (1,000 and 3,000 ppm) on several haematological values was studied on Wistar rats. Decreased haematocrit, mean corpuscular volume and white cell counts were appreciated, along with increased red cell counts. The leucocyte differential count was also modified, an important reduction of the percentage of neutrophils and monocytes being registered.

Phenanthrylalkanoic acids, IV: Syntheses and antiinflammatory activity of 2-, 3-, and 9-phenanthryl- and 9-chloro-3-phenanthryl derivatives of propanoic acid

The phenanthrylethanols 2a-d were obtained by reduction of the acetyl derivatives 1a-d and converted, through the phenanthrylethyl halides 3a-d and 4b, into the nitriles 5a-d, whose acid hydrolysis afforded the acids of the title, 6a-d. The antiinflammatory activity of these acids was measured on the carrageenin-induced edema and found as 1/3 (6a), 1/43 (6b), 1/5 (6c), and 1/7 (6d) of that of fenbufen.

Human and dogs Toxocara canis infection in a poor neighborhood in Bogota

Prevalence of Toxocara canis antibodies was studied in a poor community of Bogotá, Colombia. Two-hundred-seven patients, from both sexes and all age groups, were studied. Positive ELISA titers were found in 47.5% of the population, a high prevalence compared with reports from developed countries. T. canis ova were positive in 43.6% of fecal samples from dog puppies. An endemic pattern of the disease is described: socioeconomic status, weather, pollution, poor hygiene and a significant population of infected dogs. Neither the physical examination nor ELISA titers could detect any case of T. canis disease.

Blockade of the hydroosmotic effect of vasopressin normalizes water excretion in cirrhotic rats

Water retention in cirrhosis has classically been considered to be due to a low distal fluid delivery secondary to increased proximal sodium reabsorption. However, recent studies showing high plasma vasopressin levels in patients and rats with cirrhosis, ascites, and dilutional hyponatremia suggest that a nonosmotic vasopressin hypersecretion could be an alternative mechanism. To investigate the role of vasopressin in water retention in cirrhosis, the renal ability to excrete a water load (50 ml/kg body wt), as estimated by the minimum urinary osmolality and the percentage of the water load excreted during 3 h, was assessed in 10 control rats and in 20 cirrhotic rats with ascites and impaired water excretion and high urinary excretion of vasopressin. Twenty-four hours later, the same procedure was repeated in cirrhotic rats 20 min after the subcutaneous injection (30 micrograms/kg body wt) of d(CH2)5Tyr(Et) VAVP, an antagonist of the hydroosmotic effects of vasopressin (10 rats), or the vehicle (10 rats). Treatment with the vasopressin antagonist normalized water excretion in 9 of the 10 rats. No significant changes in renal water metabolism were observed in the group of rats given the vehicle. These results indicate that vasopressin hypersecretion is the predominant mechanism of the impairment in water excretion in rats with experimental cirrhosis and ascites.

Role of altered systemic hemodynamics in the blunted renal response to atrial natriuretic peptide in rats with cirrhosis and ascites

The natriuretic effect of pharmacological doses of atrial natriuretic peptide (ANP) is markedly reduced in cirrhosis with ascites. The current study, which includes two protocols, was carried out to investigate whether this phenomenon is related to the altered systemic hemodynamics present in cirrhosis. In protocol A, the administration of ANP (2.5 micrograms.kg-1 as a bolus followed by a constant infusion of 0.1 microgram.kg-1.min-1) to 10 rats with carbon tetrachloride-induced cirrhosis and ascites produced a significantly lower increase in diuresis (13.4 +/- 1.3 microliters/min) and natriuresis (2.3 +/- 0.3 mu Equiv/min) than in 10 control rats (56.3 +/- 1.4 microliters/min and 8.7 +/- 0.5 mu Equiv/min, respectively), indicating a renal resistance to the effect of ANP in this experimental model of cirrhosis. The reduction of arterial pressure induced by ANP was similar in both groups. However, since baseline mean arterial pressure was significantly lower in cirrhotic rats, the degree of hypotension during ANP infusion was also greater in this group of animals (82 +/- 3 vs. 109 +/- 2 mmHg). The aim of protocol B was to assess whether normalization of arterial pressure in cirrhotic rats increases the renal response to ANP. This protocol includes two groups of 10 rats with cirrhosis and ascites infused with a glucose solution containing norepinephrine (CT-NE rats) or angiotensin II (CT-AII rats) at doses to normalize arterial pressure and an additional control group of 10 cirrhotic rats with ascites receiving only glucose solution (CT rats). Angiotensin II, but not norepinephrine or glucose solution administration, was associated with a significant increase in urine volume and sodium excretion. During ANP infusion, CT rats showed a blunted diuretic and natriuretic response. In contrast, the ANP-induced increase in urine volume and sodium excretion observed in CT-NE (53.6 +/- 10.4 microliters/min and 9.3 +/- 2.2 mu Equiv/min) and CT-AII rats (98.3 +/- 11.6 microliters/min and 15.5 +/- 2.9 mu Equiv/m), was similar or even greater than that showed by the healthy rats of protocol A. The degree of hypotension during ANP administration was also similar (CT-NE, 104 +/- 2; CT-AII, 108 +/- 5 mmHg). These results suggest that the blunted response to pharmacological doses of ANP in cirrhosis with ascites is related to altered systemic hemodynamics of cirrhosis, which further deteriorates during the infusion of the peptide.

Phenanthrylalkanoic acids, III: Syntheses and biological activities of 4-phenanthryl derivatives

Reformatsky reactions between 2,3-dihydro-4(1H)-phenanthrenone (5) and ethyl alpha-bromoacetate or propanoate yield several unsaturated esters which, upon aromatization followed by saponification, lead to the 4-phenanthrylacetic (1) and 2-(4-phenanthryl)propanoic (2) acids. The analgesic and anti-inflammatory properties of 1 and 2 were measured and compared with those of Fenbufen.

Effect of atrial natriuretic peptide on arterial pressure and renal function in cirrhotic rats with ascites

Glomerular filtration rate, urine volume, sodium excretion and mean arterial pressure were measured in 10 rats with Cl4C induced cirrhosis presenting sodium retention and ascites, and in 10 control rats before and during the iv administration of the 28 aminoacid rat alpha-Atrial Natriuretic Peptide (alpha-ANP) (a bolus of 1 microgram followed by a constant infusion of 33 ng/min). alpha-ANP induced a similar increase in glomerular filtration rate and filtered sodium load in both groups of rats. In contrast, the increase in urine volume and sodium excretion produced by alpha-ANP was significantly lower in cirrhotic rats (from 13.8 +/- 1.9 to 37.9 +/- 9.1 microliters/min., and from 0.5 +/- 0.1 to 3.3 +/- 1.0 microEq/min) than in control animals (from 14.6 +/- 1.3 to 102.5 +/- 17.7 microliters/min., p less than 0.005; and from 1.0 +/- 0.3 to 14.1 +/- 3.2 microEq/min., p less than 0.001). The results indicate that in rats with experimental cirrhosis and ascites there are blunted diuretic and natriuretic responses to alpha-ANP, probably as a consequence of the exaggerated tubular sodium reabsorption present in these animals.

Atrial natriuretic factor in cirrhosis with ascites: plasma levels, cardiac release and splanchnic extraction

The aim of this study was to determine the plasma levels, cardiac release and splanchnic extraction of atrial natriuretic factor in cirrhosis with ascites. The plasma concentration of immunoreactive atrial natriuretic factor in samples obtained from an antecubital vein was measured in 18 healthy volunteers and in 35 cirrhotics with ascites. In 11 of these cirrhotics and in 11 patients admitted to the hospital for the study of a thoracic pain who had no clinical or hemodynamic signs of cardiac failure (control group), the plasma levels of immunoreactive atrial natriuretic factor in samples from the coronary sinus, right atrium, pulmonary artery, hepatic vein and femoral vein were determined and the coronary sinus blood flow measured by thermodilution. Cirrhotic patients showed significantly higher plasma levels of immunoreactive atrial natriuretic factor in each vascular territory studied than did control subjects (coronary sinus: 101.2 +/- 10.6 vs. 26.1 +/- 4.7 fmoles per ml; right atrium: 32.5 +/- 5.8 vs. 9.4 +/- 3.5; pulmonary artery: 36.8 +/- 10.1 vs. 7.5 +/- 2.4; hepatic vein: 10.7 +/- 2.0 vs. 2.7 +/- 0.8; femoral vein: 18.2 +/- 2.4 vs. 3.1 +/- 0.9; antecubital vein: 14.7 +/- 1.6 vs. 4.0 +/- 0.8). The coronary sinus blood flow was also higher in cirrhotics (200 + 22 ml per min) than in controls (105 +/- 7 ml per min). Consequently, the estimated cardiac release and cardiac production of immunoreactive atrial natriuretic factor were strikingly increased in cirrhotics (13,334 +/- 2,007 and 5,484 +/- 1,734 fmoles per min, respectively) as compared to control subjects (1,669 +/- 338 and 1,431 +/- 350 fmoles per min, respectively; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

An assessment of single doses of 8 mg sustained-release molsidomine using serial exercise tests

The effectiveness and duration of the anti-anginal action of two sustained-release preparations, molsidomine (8 mg) and isosorbide dinitrate (20 mg), were assessed by means of serial exercise tests in 12 patients with angina of effort. The tests, which were limited by the symptoms, were carried out on three consecutive days using the Bruce protocol. Each patient was tested four times each day: the first test was performed before treatment and the others were carried out 1, 4 and 8 h after administration of the drug or placebo. One hour after administration of molsidomine, the appearance of signs of ischaemia in the ECG were considerably delayed and they were reduced in magnitude. Furthermore, the length of time during which the patients were free of angina increased. After 4 h both drugs significantly delayed the onset of angina and depression of the ST segment by 1 mm. The conclusion is that at the doses used both drugs prolong the length of time in which there is no angina, but that they have no significant effect at 8 h.

Endothelial cell growth factor and ionophore A23187 stimulation of production of inositol phosphates in porcine aorta endothelial cells

The existence of a bovine brain-derived endothelial cell growth factor has recently been reported, but its mode of action is unknown. We show that the endothelial cell growth factor is a potent stimulant of inositol monophosphate release in porcine aorta endothelial cells. Although the activation of phospholipase C by this factor does not appear to be dependent on Ca2+, the Ca2+ ionophore A23187 stimulates release of inositol phosphates. It is suggested that the inositol 1,4,5-trisphosphate 3-kinase/5-phosphomonoesterase pathway could account for the ionophore-induced changes in inositol 1,3,4-triphosphate.

The molecular organization of the protein HC-IgA complex (HC-IgA)

Complexes of protein HC and monoclonal IgA1 or IgA2 or polyclonal IgA were isolated from human blood plasma. Dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting showed that all complexes contain three types of chains: two light immunoglobulin chains, one regular IgA alpha-chain, and one chain with Mr = 90,000 carrying both alpha-chain and protein HC epitopes. The complexes were split into Fab alpha and Fc alpha fragments by bacterial IgA proteases. The protein HC epitopes were linked to the Fc fragments. Complexes of protein HC and an alpha-chain devoid of the variable region and the first heavy chain constant domain could also be demonstrated to be present in the blood plasma of a patient with alpha-heavy chain disease. Pepsin digestion of HC-IgA released a fragment containing all the protein HC epitopes and the C-terminal nonapeptide of the IgA alpha-chain. The light immunoglobulin chains, the regular alpha-chain, and the 90,000-Da chain from monoclonal HC-IgA1 were isolated by preparative dodecyl sulfate-polyacrylamide gel electrophoresis and by repeated gel filtration in dodecyl sulfate-containing buffer. The N-terminal amino acid sequence of the alpha-chain was identical with that of a regular human heavy immunoglobulin chain of subgroup III. Subtractive degradations of the 90,000-Da chain displayed 2 amino acid residues in each position in a pattern suggesting simultaneous degradations of a chain identical with the regular alpha-chain of HC-IgA and of uncomplexed, low molecular weight, protein HC. All the results are compatible with a model for HC-IgA in which a single low molecular weight protein HC polypeptide chain is covalently linked, side by side, to the C-terminal nonapeptide of one of the two alpha-chains of a regular monomeric IgA unit.

Regional effect of organochlorine insecticides on cholinergic muscarinic receptors of rat brain

In different brain regions of the rat we studied the effect of chronic feeding with the organochlorine insecticides p,p'-DDT and gamma-HCH on the cholinergic muscarinic receptors. Using [3H]quinuclidinyl benzylate binding to membranes from cerebral cortex, medulla pons, diencephalon, and cerebellum it was found that the two insecticides produced a decrease in the number of muscarinic receptor sites in cerebellum; while gamma-HCH also reduced these receptors in diencephalon. In both cases no changes in receptor affinity were observed. It is suggested that the chronic treatment with these organochlorine insecticides may cause an alteration in cholinergic transmission leading to a down regulation of the muscarinic receptor in certain brain regions.

Mutagenicity study on pyrazole, seven pyrazole derivatives, and two nitroimidazoles with the L-arabinose resistance test of Salmonella typhimurium

The mutagenicity of pyrazole and seven pyrazole derivatives (4-nitropyrazole, 4-bromopyrazole, 1-methyl-4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 1-methyl-4-bromopyrazole, 4,4'-dinitro-1, 1'-methylene-dipyrazole and 4,4'-dibromo-1,1'-methylene-dipyrazole) has been investigated with the L-arabinose forward mutation assay of Salmonella typhimurium. Two nitroimidazoles (1-methyl-5-nitroimidazole and metronidazole) were included as reference drugs. The mutagenicity of each chemical was determined by both preincubation and liquid tests, in the presence or absence of S9 microsomal fraction. The mutagenic response was expressed as the absolute number of L-arabinose resistant mutants growing in selective plates, supplemented with traces of D-glucose. Strain BA13 with a wildtype lipopolysaccharide barrier was used as a comparison to the deep rough derivative BA9. No mutagenic effect was detected with pyrazole and two of its derivatives, 1-methyl-4-bromopyrazole and 4,4'-dibromo-1,1'-methylene-dipyrazole. The other five pyrazole derivatives were mutagenic to different degrees, although their mutagenic potencies were always considerably lower than those of the two nitroimidazoles. The results suggest that 4-nitropyrazoles, as well as 4,4'-dinitro-1, 1'-methylene-dipyrazoles, should be investigated further as alternatives to, or even substitutes for, the currently used nitroimidazoles.

[Effect of the method of blood extraction on plasma levels of renin in the Wistar rat]

To investigate the influence of blood extraction conditions on the renin-angiotensin system in rats, plasma renin activity (PRA) and plasma renin concentration (PRC) were measured in blood samples obtained by different methods. PRA and PRC in samples obtained by chronic catheterization, cardiac puncture without anesthesia, and decapitation immediately following light ether anesthesia were not significantly different from those obtained by simple decapitation (control group). In contrast, PRA and PRC in samples obtained by cardiac puncture and cavernous sinus puncture after light ether anesthesia were significantly (p less than 0.01) higher than those obtained in the control group. There was a significant direct correlationship between PRA and PRC in all samples studied (r = 0.87, p less than 0.001). The present results suggest that light ether anesthesia increases renin levels, except when blood samples are taken by decapitation, and that chronic catheterization and cardiac puncture are the choice blood extraction methods to evaluate the renin-angiotensin system in rats.

Toxic-oil syndrome. Gallium-67 scanning and bronchoalveolar lavage studies in patients with abnormal lung function

The toxic-oil syndrome (TOS) is a multisystem disorder whose etiology and pathogenesis are as yet unknown. Lung alterations persist in a significant number of TOS patients due to the underlying vascular lesion. Computer-assisted 67Ga scanning and bronchoalveolar lavage (BAL) studies were performed in 14 TOS patients with sustained abnormal diffusing capacity for carbon monoxide (Dco). No significant difference was observed between the 67Ga uptake index of the TOS and control populations. Likewise, there was no significant difference in the number of effector cells recovered from the lungs of TOS patients and controls by bronchoalveolar lavage. However, a rise in IgA and IgG concentrations (p less than 0.002) and a fall in alpha 1-antitrypsin (p less than 0.05) and transferrin (p less than 0.01) were observed in the TOS group. Phospholipid and lecithin concentrations in the lavage fluid were similar for patients and controls. The alveolar macrophage function assayed in three TOS patients was normal. These observations raise new questions about the outcome of lung pathology in TOS and warrant further follow-up studies of the lung abnormalities observed.