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Biomedical subjects

P Ferrari

Publications and source records attributed to P Ferrari.

At least 19 recordsLinked to original sources
PubMed1979

A renal abnormality as a possible cause of "essential" hypertension.

The renal abnormality which causes hypertension in the Milan hypertensive strain of rats disappears as hypertension develops. Because of the many analogies between the condition in these rats and "essential" hypertension in man, the same pattern of change may occur if a renal abnormality is the cause of essential hypertension in man. This hypothesis was tested in two groups of young normotensive subjects matched for age, sex, and body-surface area; in the first group both parents were hypertensive, and in the second group both parents were normotensive. Renal plasma-flow, glomerular filtration-rate, plasma-volume, plasma-renin activity, plasma-concentrations of Na+, K+, and catecholamines, 24 h urinary excretion of Na+, K+, and aldosterone, and the cardiac index were measured so that renal function and the role of factors affecting blood-pressure regulation could be assessed. Renal plasma-flow was significantly higher (p less than 0.01) in the first group, whereas results of tests for all the other factors were almost the same in both groups. The hypothesis that a primary kidney abnormality causes hypertension in a proportion of patients with essential hypertension is proposed.

Adult↗
PubMed1979

Hypotensive action and side-effects of flutonidin in normal subjects. A double-blind controlled trial.

In a double blind study, planned as a 7 x 7 latin square, three oral doses of flutonidin (0.5, 1, 2 mg), of clonidine (0.0075, 0.150, 0.300 mg) and of a placebo were administered to 7 normal volunteers on 7 different treatment days, with an interval of 3 days. On each treatment day sitting blood pressure, heart rate and reaction time were measured, and sedation and dry mouth evaluated before the 1, 2, 3, 4, 6, and 8 h after administration. The placebo did not modify the basal value of any variable. Flutonidin and clonidine produced dose-related effects on blood pressure, heart rate, sedation and dry mouth, but did not influence reaction time. Analysis of the dose-response curves demonstrated that the effect of flutonidin was one-fifth to one-twelfth that of clonidine, depending on which variable was considered.

Adult↗
PubMed1979

Metabolites of 3-hydrazino-6-[bis-(2-hydroxyethyl)amino]pyridazine dihydrochloride in rat urine.

In 24 hr urine of rats orally given 150 mg/kg of 3-hydrazino-6-[bis-(2-hydroxyethyl)amino]pyridazine dihydrochloride (DL 150), no unchanged compound was detected. Three metabolites, less polar than DL 150, were isolated, their structures assigned by UV, MS, IR and 1H NMR spectroscopies, and confirmed by synthesis. They are: 3-[bis-(2-hydroxyethyl)amino]-6-isopropoxypyridazine (1); 3-[bis-(2-hydroxyethyl)amino]pyridazine (2); 3-methyl-6-[bis-(2-hydroxyethyl)amino]-s-triazolo[4,3-b]pyridazine (3). The metabolism of DL 150 in the rat follows some of the metabolic pathways reported for hydralazine.

Animals↗
PubMed1979

[Cardiovascular effect of 1,2,4-benzothiadiazine-1,1-dioxide derivatives. VIII].

A series of carboxy- and carbomethoxyalkyl derivatives of 3-amino-1,2,4-benzothiaidazin-1,1-dioxide either substituted or unsubstituted in the benzene ring [compounds (I leads to XVIII)] was prepared and tested for cardiovascular activity. It was found that the introduction of a carboxy-or carbalkoxy-group in the omega position of 3-alkylamino derivatives of 1,2,4-benzothiadiazine-1,1-dioxide usually causes marked decrease or abolition of the cardiovascular activity shown by the parent compounds. The negative effect on the pressor trace (hypotension and increase in differential pressure) is more frequent and significant than that on bradycardial activity.

Animals↗
PubMed1979

[Heteroarylalkanoic acids with potential anti-inflammatory activity].

A series of (3-oxodihydro-1,2,4-benzothiadiazin-1,1-dioxide-3-yl)acetic acids [compounds of type (A)] and (1,2,4-benzothiadiazin-1,1-dioxide-3-yl)oxyacetic acids [compounds of type (B)] were synthesised and tested for antiinflammatory activity. Preliminary tests showed certain compounds to have a significant level of antiinflammatory activity in rat paw edema induced by carrageenan. It was found that the antiinflammatory activity of this series of compounds depends on the nature, number and position of the substituents on the benzene ring.

Acetates↗
PubMed1978

Increase in plasma extracellular fluid volume ratio caused by bilateral nephrectomy in patients on maintenance hemodialysis.

Changes, observed in rats after bilateral nephrectomy, in blood pressure and in the relation betwen plasma volume-extracellular fluid volume or plasma volume-interstitial fluid volume, are consistent with the postulation that the kidney secretes a substance that regulates, to some degree, the compliance of the interstitial space. In order to evaluate the possibility that this also occurs in humans, we have carried out a retrospective analysis of measurements of extracellular fluid volume, plasma volume, and blood volume made prior to and after bilateral nephrectomy in a group of 9 patients. It was observed that significant increases had occurred in both the plasma-extracellular fluid volume ratio (0.22 before, 0.26 after) and in the blood-extracellular fluid volume ratio (0.27 before, 0.32 after). These data are consistent with a reduction in compliance of the interstitial compartment caused by bilateral nephrectomy in man, even though other explanations cannot be excluded.

Adult↗
PubMed1978

Polymorphism of 1-methyl-2-nitro-5-vinylimidazole.

Three polymorphic forms of 1-methyl-2-nitro-5-vinylimidazole, a potential antimicrobial drug, have been isolated and characterized by thermomicroscopy, differential scanning calorimetry, infrared spectroscopy and X-ray powder diffraction. On the basis of some infrared bands, the hypothesis has been made that the different packing of forms I and II was due to the existence of the molecule in two different conformations in the two forms. The direct confirmation of the hypothesis has been sought by X-ray diffraction of single crystals, but a suitable crystal was obtained only for form II. Form II is orthorhombic, space group Pbca, with unit-cell dimensions: a = 13.05, b = 10.83, c = 10.21 A; Z = 8. From the X-ray analysis, carried out by direct methods, the molecule is planar and the vinyl group is cisoid to the heterocyclic CH group. Then, the existence of the molecule as transoid conformation in form I still remains a hypothesis.

Calorimetry, Differential Scanning↗
PubMed1978

[Cardiovascular action of 1,2,4-benzothiadiazine-1,1-dioxide derivatives. VI].

A series of 3,4-dihydro derivatives of 6-chloro-, 7-chloro-, 5,7-dichloro-, 6,7-dichloro-, 5,7-dibromo-, 5-nitro-7-chloro-, 7-nitro-, 7-amino-1,2,4-benzothiadiazine-1,1-dioxide, various substituted on the heterocyclic carbon, was prepared and tested for cardiovascular activity. It was found that in this series of compounds cardiac activity predominates and is exclusively of the depressant type. Bradycardial activity seems to be affected both by the nature of the substituent on the heterocyclic carbon atom and by the substituents on the benzene ring. An alkyl chain of three carbon atoms, normal or alpha-ethylsubstituted, on C3 and the presence of a chlorine atom in positions 6 or 7 seem to be the most significant structural features for this activity. Some of the substances tested showed a pressor effect (hypotension and/or increase in differential pressure).

Animals↗
PubMed1978

[Cardiovascular action of 1,2,4-benzothiadiazine-1,1-dioxide derivatives. VII].

A series of dimethylamino-, diethylamino-, pyrrolidyl- and morpholylalkyl derivatives of 3-amino-1,2,4-benzothiadiazine-1,1-dioxide (compounds I leads to XX) was prepared and tested for cardiovascular activity. It was found that substitution of the alkyl group with the above mentioned groups in 3-amino-1,2,4-benzothiadiazine-1,1-dioxide derivatives in most cases causes marked dissociation of hypotensive activity from bradycardial activity and also disappearance or great reduction in the effect on differential pressure. It was also found that hypotensive activity is particularly dependent on the nature of the basic chain in the two components: length of the carbon chain between the two nitrogens and nature of the basic grouping. For the first component a chain of three carbon atoms seems the most effective and for the second the diethylamino group seems the most favourable. In addition, substituents in the benzene ring influence hypotensive activity, often positively, and 6,7-dichlorosubstitution in some compounds also affects the increase of differential pressure.

Animals↗
PubMed1976

Effect of amantadine on drug-induced parkisonism: relationship between plasma levels and effect.

Amantadine, administered at a dose of 200 mg/day, antagonized the extapyramidal symptomatology induced by neuroleptic drugs in fifteen psychiatric patients. Steady-state levels were reached within 4-7 days of treatment. Individual plasma levels ranged from 200-900 ng/ml. Apparent plasma half-lives varied from 10-28.5 h with an apparent VD of 200-400 litres. A significant relationship was found between the plasma levels of amantadine and the effects on the extrapyramidal symptomatology. The data suggest a direct effect of amantadine on dopaminergic receptors.

Adult↗