Urinary output of endogenous monoamine oxidase inhibitor and isatin during acute migraine attacks

Urinary output of endogenous monoamine oxidase (MAO) inhibitory activity, was significantly raised in serial samples collected across a migraine attack compared with collections during attack-free periods and in healthy controls, which did not differ from each other. There was a highly significant correlation in output between isatin, a major fraction of the MAO inhibitory activity, and output of the MAO inhibitory activity itself. However, although there was a tendency towards increased isatin excretion during migraine attacks, it failed to reach statistical significance.

Isatin (indole-2,3-dione) in urine and tissues. Detection and determination by gas chromatography-mass spectrometry

A simple procedure based upon capillary column gas chromatography-mass spectrometry (GC-MS) is described for the detection and determination of isatin (indole-2,3-dione) in body fluids and tissues. After addition of 5-methylisatin as internal standard to urine or tissue homogenates, organic extracts are dried and derivatized successively with hydroxylamine hydrochloride and the reagent N-tert.-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). The tert.-butyldimethylsilyl derivatives obtained show good GC-MS properties and allow quantification by selected-ion monitoring of m/z 333 (isatin) and m/z 347 (internal standard). Adult and newborn human urine output values lie in the ranges 0.4-3.2 mg/mmol of creatinine (5-30 mg per 24 h) and 0.002-0.518 mg/mmol of creatinine, respectively. There is a discontinuous regional distribution in rat tissues. The GC-MS properties of a number of derivatives formed by successive reaction of isatin with hydroxylamine hydrochloride (or methoxyaminehydrochloride or ethoxyamine hydrochloride) and MTBSTFA, bis(trimethylsiyl)trifluoroacetamide, pentafluoropropionic anhydride or pentafluorobenzyl bromide are also described.

Effects of captopril on glucose tolerance in elderly patients with congestive cardiac failure

A prospective study was carried out to investigate the effects of the ACE inhibitor captopril on glucose tolerance in 14 elderly patients, aged 76 to 89 years, who had co-incident cardiac failure and stable Type II diabetes mellitus. Patients were maintained on their diet and diabetic therapy and were given 12.5 mg captopril twice daily. Clinical findings, including signs of cardiac failure, body weight and blood pressure, biochemical profile and chest X-ray appearance were documented at each visit. Blood glucose tolerance testing was carried out immediately before starting captopril and again 28 days later. A reduction in symptoms of heart failure occurred in all patients and 5 of them reduced their New York Heart Association grade of heart failure. Significant improvement in glucose tolerance occurred in all patients. Four were able to reduce hypoglycaemic therapy and 1 was able to stop his hypoglycaemic agents. This potentially valuable additional benefit of captopril in improving glucose tolerance has not yet been shown to occur with other ACE inhibitors.

Clinical pharmacology of moclobemide, a new reversible monoamine oxidase inhibitor

The clinical pharmacology of the new reversible monoamine oxidase (MAO) inhibitor, moclobemide, was examined in three separate studies in healthy male volunteers. In a single oral dose study, moclobemide (25-150 mg) was rapidly absorbed from the gastrointestinal tract and had a relatively short plasma half-life (mean 1.3 h after 150 mg). A decrease in the plasma concentrations of the noradrenaline metabolite 4- hydroxy-3-methoxyphenylglycol (HMPG), however, indicated a longer time to peak pharmacodynamic effect and longer duration of activity. Assay of platelet MAO activity did not reveal any evidence of irreversible inhibition of the B form of the isoenzyme. Single oral doses of moclobemide (150 and 300 mg) significantly lowered the threshold to the cardiovascular effects ('cheese reaction') of intravenous tyramine. However, after repeated administration of 100 mg three times daily for over 2 weeks, moclobemide caused significantly less potentiation than did phenelzine (15 mg three times per day) on the cardiovascular effects of oral tyramine, a clinically more relevant model. The MAO-B inhibitor, selegiline (5 mg once daily), also lowered the oral tyramine threshold significantly. Moclobemide was generally well tolerated by these healthy volunteers.

Platelet [3H]imipramine binding in migraine and tension headache in relation to depression

Platelet [3H]imipramine binding was measured in 40 migrainous (7 classical and 33 common) and 17 tension headache patients and in 28 normal controls. A significant reduction in Bmax was found in migraine compared with controls (p less than 0.05) but not in tension headache. In migraine, there was no significant relationship between Bmax and depression or anxiety score on the self-rating Hospital Anxiety and Depression (HAD) Scale, suggesting that the reduction in Bmax is a concomitant of migraine itself rather than a manifestation of associated depression. Preliminary evaluation using the Schedule of Affective Disorders and Schizophrenia-Lifetime Version (SADS-L) tended to confirm this conclusion.

Tyramine conjugation test distinguishes unipolar from bipolar depressed patients and controls

Tyramine sulphate conjugation following oral tyramine administration (the tyramine test) has previously been found to distinguish endogenous unipolar from neurotic depression and appears to be a trait marker. In this study, the test was used in 24 unipolar depressed patients compared with similar sized matched groups of bipolar depressed patients and normal controls. Most of the depressed patients in each group showed endogenous features. The study found that whereas tyramine sulphate conjugation was significantly impaired in unipolar patients, values in the bipolars were similar to those of controls. These results provide further evidence for the biological difference between unipolar and bipolar depression.

Release of (14C)5-hydroxytryptamine from human platelets by red wine

Red wine, at a final dilution of 1/50, caused release of [14C]5-hydroxytryptamine (5-HT) from preloaded platelets, an effect which was not observed with any white wines or beers tested. Since 5-HT, is probably released from body stores during migraine attacks and red wine is known to provoke migraine episodes in susceptible individuals, release of 5-HT, possibly from central stores, could represent a plausible mechanism for its mode of action.

Can we predict and/or prevent type I diabetes?

The highest risk for the development of type I diabetes resides with first-degree relatives of the diabetic proband, this risk being in the order of 2.9%, 6.6% and 4.9% for parents, siblings and children of the proband, respectively. The major genetic markers associated with the development of insulin-dependent diabetes mellitus (IDDM) is the possession of the HLA alleles DR3/DR4 and more recently the absence of aspartate in the 57th position on the beta-chain of the HLA DQ gene (HLA DQ beta Asp 57 negative). The most important auto-immune marker for predicting preclinical IDDM is the presence of high titres (greater than 40 Juvenile Diabetes Foundation units) of islet cell antibodies (ICA), while the finding of insulin auto-antibodies (IAA) is a good predictive marker in children less than 5 years of age. The presence in a susceptible individual of ICA plus IAA is a better predictor of impending IDDM than the presence of either of these two markers alone. Antibodies which precipitate an islet membrane protein (MW 64K) are highly sensitive and specific markers of preclinical IDDM. The presence of 64K antibodies may well be the most important predictive marker of impending IDDM in the future. The progressive decline of the first phase of insulin secretion in response to an intravenous glucose challenge is associated with the onset of IDDM within 18 months. Of the immunotherapeutic agents at present used in clinically manifest IDDM, azathioprine has been shown to be ineffective in increasing the remission phase, while the value of nicotinamide is controversial.(ABSTRACT TRUNCATED AT 250 WORDS)

Is the lung a 'target organ' in diabetes mellitus?

Histopathologic evidence of lung involvement in subjects with diabetes mellitus has included thickened alveolar epithelial and pulmonary capillary basal laminae, the latter being suggestive of existing pulmonary microangiopathy. Abnormal pulmonary function has been detected in some diabetic patients; the most consistent abnormalities are reduced lung volumes in young (aged less than 25 years) insulin-dependent diabetic subjects, reduced pulmonary elastic recoil in both young and adult (aged greater than 25 years) diabetic subjects, and impaired diffusion due to a reduced pulmonary capillary blood volume in the adult group. Nonenzymatic glycosylation-induced alteration of lung connective tissue is the most likely pathogenetic mechanism underlying mechanical pulmonary dysfunction in diabetic subjects, while the most tenable explanation for impaired pulmonary microangiopathy. these patients is the presence of underlying pulmonary microangiopathy. The finding of abnormal lung function in some diabetic subjects suggests that the lung should be considered a "target organ" in diabetes mellitus; however, the clinical implications of these findings in terms of respiratory disease are at present unknown.

High incidence of endogenous depression in migraine: confirmation by tyramine test

Forty patients with migraine who were attending a specialist clinic were interviewed with the Schedule for Affective Disorders and Schizophrenia--Lifetime version. Sixteen (40%) had a history of major depression which was of endogenous type in 15, according to Research Diagnostic Criteria. The tyramine test, a previously established trait marker for endogenous depression, showed that the migraine group as a whole had significantly low values compared with 14 normal controls, due almost entirely to low values in the endogenous depressive subgroup; there were no differences between diet-sensitive and non-diet-sensitive migraine patients. Thus depression in patients with migraine seems unlikely to be secondary to migraine per se. A substantial subgroup of patients with migraine may possess an inherent predisposition to endogenous depression.

Stress reduces in vivo inhibition of monoamine oxidase by phenelzine in rat brain

The level of inhibition of rat whole brain monoamine oxidase activity produced by the irreversible monoamine oxidase inhibitor phenelzine has been studied with or without concurrent cold restraint stress. We have found that phenelzine caused significantly less enzyme inhibition when given during a period of stress than during a control period. Thus, stress can reduce the in vivo potency of MAO inhibitors. This would be compatible with an increased production of the reversible, endogenous monoamine oxidase inhibitor, tribulin, competing for the active site of the enzyme.

Isatin and tribulin concentrations are increased in rabbit brain but not liver following pentylenetetrazole administration

Isatin has recently been identified in rat tissues and normal human urine where it constitutes the major part of the endogenous monoamine oxidase inhibitor, tribulin. In this study, we have measured both isatin (by gas chromatography/mass spectrometry) and tribulin (inhibition of a standard rat liver monoamine oxidase preparation) in extracts of rabbit brains and livers after intravenous administration of the anxiogenic, proconvulsant agent pentylenetetrazole. There were increased levels of both isatin and tribulin in rabbit brains, but not in livers, after pentylenetetrazole, compared with saline treated controls. This finding supports the hypothesis that isatin is a component of tribulin activity and may have a role in anxiety or epilepsy.

The destination and dependency of patients discharged from care of the elderly units in the West Midlands

Between November 1988 and January 1989 a prospective survey was undertaken on patients aged 65 years and over who were discharged from the care of geriatricians in seven District General Hospitals. The survey aimed to provide a regional perspective on patient dependency by relating dependency at discharge to the discharge destination. The findings show that the majority of patients were relatively independent and most returned home. A significant number of the very dependent patients were discharged to the community with private residential and nursing homes making an important contribution to the placement of highly dependent patients.

Endogenous urinary monoamine oxidase inhibitor excretion in Parkinson's disease and other neurological disorders

In this study, urinary output of both neutral (tribulin) and basic monoamine oxidase inhibitory activity was measured in parkinsonian patients, other neurological patients and controls. No significant differences in output were found between these different groups. In general, tribulin output rose with age, in parallel with known changes in monoamine oxidase B activity.

Psychiatric morbidity, platelet monoamine oxidase and tribulin output in headache

A significantly higher proportion of patients with headache showed scores in the psychopathological range of the General Health Questionnaire (GHQ) compared with controls, with ratings particularly high on the anxiety and depression subscales. Across the whole group, there was a significant negative correlation between platelet monoamine oxidase (MAO) activity and GHQ score overall, and with the anxiety and depression subscales. There was a significant positive correlation between platelet MAO activity and urinary output of the endogenous MAO inhibitor, tribulin. Within the migraine group, there was a significant negative correlation between tribulin output and GHQ score. These findings suggest that the biochemical nature of the anxiety associated with migraine may differ from that in other conditions such as generalized anxiety disorder where high platelet MAO activity and high tribulin output have been reported.