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Biomedical subjects

C Martini

Publications and source records attributed to C Martini.

At least 199 records · Page 11Linked to original sources
PubMed1989

Further investigation on benzodiazepine binding inhibitory activity in patients with major depression or panic disorder and in healthy volunteers.

Preliminary findings regarding the presence of plasmatic benzodiazepine binding inhibitory activity (BBIA) in 14 psychiatric patients prompted us to investigate it further in larger samples of psychiatric patients (n = 44) and in healthy controls (n = 14). The results have shown that BBIA is present in all the subjects included with statistically significant differences between the patients and controls. The highest concentrations were found in the patients with no difference between anxious or depressed patients, and the lowest in the healthy controls. These findings indicate that BBIA might play a role in the pathophysiology of some manifestations of anxiety.

Adult↗
PubMed1989

Possible involvement of endogenous opioids in beta-cell hyperresponsiveness in human obesity.

Since increased opiate production in obesity has been reported, the effects of naloxone in obese subjects were studied in order to ascertain whether endogenous opioid peptides play a role in the abundant insulin secretion of obesity. The results obtained showed that intravenous administration of naloxone considerably reduced insulin of obese subjects to a mixed meal, whereas it did not modify the blood insulin response to arginine or glucose infusion. Glucagon secretion to ingestion of a mixed meal and to arginine infusion was not modified by the opioid receptor blocking agent. This study seems to indicate that hyperproduction of endogenous opioid peptides in obesity increases insulin secretion stimulated by food intake, whereas it does not appreciably affect insulin production stimulated by circulating glucose or aminoacids.

Adolescent↗
PubMed1989

Dipyrazolo[5,4-b:3',4'-d]pyridines. Synthesis, inhibition of benzodiazepine receptor binding and structure-activity relationships.

Some 2,6,8-trisubstituted dipyrazolo[5,4-b:3',4'-d]pyridin-3-ones related to the CGS series were synthesized and tested for their ability to displace [3H]flunitrazepam binding from bovine brain membranes. However the affinity for the benzodiazepine receptor of the tested compounds was lower than that of the CGS series, although it was comparable to that of chlordiazepoxide. It follows that some structure-activity relationships on the tested compounds can be drawn.

Animals↗
PubMed1988

Specific inhibition of benzodiazepine receptor binding by some 1,2,3-triazole derivatives.

Certain 1,2,3-triazole derivatives were prepared and tested for their ability to displace [3H]diazepam from bovine brain membranes. From these compounds, the quinolytriazole derivatives (14, 15, 16, 17) were clearly the most potent, while the naphthyl- and the naphthyridyl-triazoles were considerably less active. The p-nitrophenyl derivative (15) was the compound that bound with the highest affinity within the quinolyltriazole compounds class. The replacement of the p-nitrophenyl group with other substituents greatly decreased the binding activity. From a Lineweaver-Burk analysis of 11, it appears that the inhibition is competitive.

Animals↗
PubMed1988

An anomalous effect of N-isopropyl substitution in determining beta-adrenergic activity.

We report unexpected results in an investigation of cyclic analogues of dopamine and norepinephrine possessing the structures 1-(aminomethyl)-5,6-dihydroxy-1,2,3,4-tetrahydronaphthalene (3) and 1-(aminomethyl)-5,6-dihydroxy-1,2,3,4-tetrahydro-1-naphthalenol (7). N-Isopropyl substitution of these compounds, providing 4 and 8, brings about the total disappearance of their stimulant activity on beta-adrenergic receptors. On the basis of current knowledge about the structure-activity relationship of adrenergic drugs, it is difficult to provide an explanation for these results; however a tentative rationalization based on conformational considerations is suggested.

1-Propanol↗
PubMed1987

3-[(2-ethoxyphenoxy)methyl]piperidine derivatives. Synthesis and antidepressant activity.

The 3-[(2-ethoxyphenoxy)methyl]piperidine derivatives 3-5 were synthesized and screened as potential antidepressant agents by the reserpine interaction test in mice and the evaluation of reuptake inhibition of biogenic amines in pig brain synaptosomal fractions. In addition, their anticonvulsant activity, tested by pentyleneetrazole antagonism, and approximate acute toxicity were evaluated. In vivo and in vitro tests showed that compounds 3 and 5 possess a biological activity comparable to that of the antidepressant drug viloxazine.

Animals↗
PubMed1987

Affinity labeling of adenosine A1 binding sites.

The adenosine A1 receptors of sheep brain membranes have been identified by the specific binding of radiolabeled cyclohexyl[3H]adenosine ([3H]CHA). Pretreatment of membranes with periodate-oxidized CHA causes a dose- and time-dependent decrease in the number of binding sites. No decrease occurs when membranes are pretreated with CHA. Binding of [3H]CHA to the remaining sites occurs with the same characteristics as binding to the untreated receptor population.

Adenosine↗
PubMed1987

A 3H-flunitrazepam binding inhibitor is present in psychiatric patients' sera.

We investigated the possible existence of endogenous compounds acting on benzodiazepine central receptors in the serum of patients with panic attacks or depression. Our results show the presence of a substance which inhibits the 3H-flunitrazepam binding specifically in the samples taken from the patients' groups, and which is not present in normal controls, in the range of concentrations used. This compound has a molecular weight below 1,000 daltons, is heat-stable, and resistant to proteolytic degradation. The demonstration of this inhibitor opens new perspectives in the study of the biochemistry of anxiety.

Adolescent↗
PubMed1986

Pyrazolo[4,5-c]quinolines. 3. Synthesis, receptor binding, and 13C NMR study.

Some 1-aryl-3-methylpyrazolo[4,5-c]quinolin-4-ones, were prepared and tested for their ability to displace specific [3H]flunitrazepam binding from bovine brain membranes. The 1-meta-aryl derivatives were the compounds that bound with the highest affinity within this class. Our 13C NMR study suggested a correlation between the binding affinity and the chemical shift value of a carbon atom of the tricyclic system.

Animals↗
PubMed1986

Effect of exercise on plasma kallikrein and muscular phospholipase A2 activity in rats.

Many experimental observations show that prolonged physical exercise produces an increase of muscular glucose uptake. Recent findings suggest that the kallikrein-kinin-prostaglandin system may be related to this phenomenon, but so far, no direct evidence of quantitative alteration in this system has been observed during exercise. We measured plasma kallikrein and muscular phospholipase A2 activity, respectively the first and the last steps of reactions leading to prostaglandin synthesis. We demonstrated, for the first time, that during exercise plasma kallikrein activity increases in rats. We also observed an increase of muscular phospholipase A2 activity after exercise and a positive correlation between these parameters. Our findings demonstrate, under physiological conditions of enhanced muscular glucose uptake, a concomitant significant increase of plasma kallikrein and muscular phospholipase A2 activity, supporting the hypothesis that activation of the kallikrein-kinin-prostaglandin system may play some part in the enhanced muscular glucose uptake during physical activity.

Animals↗
PubMed1986

Pyrazolo[4,5-c]quinolines. 2. Synthesis and specific inhibition of benzodiazepine receptor binding.

A series of 1-aryl-3,5-dimethyl-4,5-dihydro-1H-pyrazolo[4,5-c]quinolin-4-ones (2a-e) and 1-aryl-3-methyl-1H-pyrazolo[4,5-c]quinolines (3-7a-e) bearing different substituents at position 4 were prepared and tested for their ability to displace specific [3H]flunitrazepam binding from bovine brain membranes. The 5-N-methyl derivatives 2a-c,e were the compounds that bound with the highest affinity within this class. The replacement of the carbonyl group with other substituents and the resulting aromatization of the pyridine moiety greatly decreased the binding affinity. From a Lineweaver-Burk analysis on the most active compound 2b, it appears that the inhibition is a competitive one.

Animals↗