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Biomedical subjects

D L Murphy

Publications and source records attributed to D L Murphy.

At least 343 records · Page 19Linked to original sources
PubMed1985

Therapeutic responses to tricyclic antidepressants and related drugs in non-affective disorder patient populations.

Although therapeutic responsiveness to tricyclic antidepressants has been primarily associated with the affective disorders, clinical investigations in the last decade have suggested that non-affective disorders such as panic disorder, obsessive-compulsive disorder, anxiety disorder, bulimia, enuresis, migraine, and the chronic pain syndrome may also respond to tricyclics and other antidepressants. This therapeutic responsiveness may sometimes be related to improvement in secondary depressive symptoms, but may also clearly occur in the absence of secondary depression; in particular, improvement in the core symptoms of at least some of these disorders may occur without a change in mood. Furthermore, many patients with these disorders display psychobiologic abnormalities that show many similarities, but also some differences, compared to those observed in patients with affective disorders, despite the frequent absence of affective symptoms. While an improvement in subclinical or "masked" depression remains one hypothesis linking tricyclic responsiveness and shared biological abnormalities in this diverse group of diagnostic entities, an alternative hypothesis (the "ven disorder" hypothesis) is presented, suggesting the possibility that tricyclic and other antidepressant-responding patients have a core disorder with common psychobiologic abnormalities but multiple clinical and diagnostic presentations. An alternative hypothesis (the "shotgun" hypothesis) suggests that the multiple actions of tricyclics (e.g. on adrenergic receptors vs. muscarinic receptors vs. serotonin system changes) may each be differentially important in the therapeutic outcome in patients with specific or predominant problems in one or another of these areas. An examination of both the similarities and differences among the non-affective, tricyclic-responsive disorders and the affective disorders may provide clues about the important psychobiologic elements in these disorders, and to the mode of action of tricyclic antidepressants and related drugs across the psychiatric disorder spectrum.

Anorexia Nervosa↗
PubMed1985

Biological alterations in the primary affective disorders and other tricyclic-responsive disorders.

Noradrenergic function was studied in patients with primary affective disorder and other tricyclic-responsive disorders including obsessive-compulsive disorder, anorexia nervosa and panic attack/agoraphobia in medication-free states. Pre-synaptic noradrenergic activity was assessed by assaying plasma concentrations of norepinephrine (NE) and its metabolite 3-methoxy,4-hydroxyphenylglycol (MHPG). Noradrenergic receptor responsiveness was evaluated by measuring plasma growth hormone (GH), MHPG, and NE responses to clonidine. Binding of tritiated dihydroergocriptine (3H-DHE) and biochemical responsiveness of alpha 2-adrenergic receptors were measured in platelet preparations. These studies suggest that noradrenergic activity may be altered in several tricyclic-responsive disorders and are consistent with the possibility that tricyclic antidepressants may serve to stabilize a dysregulated noradrenergic system in patients from several diagnostic categories.

Adult↗
PubMed1985

Tricyclic response in obsessive compulsive disorder.

Therapeutic responses to the tricyclic antidepressant clomipramine have been demonstrated in five double blind studies of patients with obsessive compulsive disorder. Biological alterations in patients with obsessive compulsive disorder resemble those of depressed patients for the dexamethasone suppression test, for some measures of sleep physiology, and in similar neuroendocrine responses to clonidine. Clomipramine's antiobsessional effect does not require high baseline depression ratings or biological abnormalities similar to those seen in depressives. Preliminary results suggest that in contrast to depressives, patients with obsessive compulsive disorder may respond to clomipramine but not to the tricyclic antidepressant desipramine.

Adolescent↗
PubMed1985

Neuroendocrine effects of M-chlorophenylpiperazine, a serotonin agonist, in humans.

M-Chlorophenylpiperazine (m-CPP) produces effects on the central serotonergic system in animals compatible with direct agonist activity on postsynaptic serotonin receptors. Although it is a metabolite of the antidepressant trazodone, m-CPP has not previously been given to humans. To evaluate the neuroendocrine, behavioral, and physiological effects of m-CPP, 15 normal subjects were given 0.5 mg/kg m-CPP, orally. Administered acutely under double blind, placebo-controlled conditions, m-CPP was well tolerated by 14 of the 15 subjects; it produced significant increases in plasma PRL and cortisol and in body temperature, without changing pulse or blood pressure. The mean (SD) maximal increases over baseline for PRL, cortisol and temperature were 13.4 (9.9) ng/ml, 10.1 (6.7) micrograms/100 ml, and 0.4 (0.2) C, respectively. A small but significant increase in self-rated activation-euphoria and anxiety was noted by some subjects, whereas there were no significant effects on ratings of depression, dysphoria, altered self-reality, or functional impairment. These results are similar to those for other serotonin agonists and, thus, suggest that m-CPP merits further study as a pharmacological probe of serotonergic responsivity in humans. The results also support the hypothesis that serotonin plays a role in the regulation of PRL, cortisol, body temperature, and mood.

Adult↗
PubMed1985

Erythrocyte deformability changes in autoimmune hemolytic anemia during development of NZB mice and their (NZB/NZW)F1 hybrid.

NZB and B/W hybrid mice develop compensated hemolytic anemia during the first year of their life. By the age of 3-5 months, their erythrocytes show evidence of spherocytosis, increased osmotic fragility and decreased whole cell deformability, as measured by ektacytometry, a laser diffraction technique. The presence of spherocytes with decreased surface area/volume ratio was confirmed by scanning electron microscopy and osmotic gradient ektacytometry. Whereas these abnormalities persisted and worsened in the NZB mice with further growth, they gradually improved and reverted to normal by the age of 12 months in B/W mice. This spontaneous improvement seems to be due to the accumulation of red cell membrane lipids reflecting the lipemia of immune complex nephritis in B/W mice. The implications of these findings in the modulation of autoimmune hemolytic anemia are discussed.

Age Factors↗
PubMed1984

Differential effects of clorgyline on catecholamine and indoleamine metabolites in the cerebrospinal fluid of rhesus monkeys.

The effects of acute and chronic administration of clorgyline, an irreversible inhibitor of monoamine oxidase type A (MAO-A), on the deaminated metabolites of norepinephrine, dopamine and serotonin were examined in rhesus monkey cerebrospinal fluid (CSF). Acute clorgyline treatment resulted in highly significant, dose-dependent reductions in 3-methoxy-4-hydroxyphenylglycol (MHPG) of 50% (1 mg/kg) and 68% (2 mg/kg) compared to pretreatment values. Chronic clorgyline administration (0.25 to 0.5 mg/kg X 24 days) resulted in a 67% reduction in CSF MHPG. In contrast, the concentrations of 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) were less affected by acute clorgyline administration, being reduced significantly only after the 2 mg/kg dose, which lowered 5-HIAA 27% and HVA 48%. Chronic clorgyline treatment had no significant effect on the CSF concentrations of HVA and 5-HIAA. These data, which suggest that MAO-A inhibition by clorgyline in vivo is more closely associated with changes in the noradrenergic than the serotonergic or dopaminergic systems in nonhuman primates, are in general agreement with the effects of clorgyline on CSF and urinary biogenic amine metabolites in man. They differ from several in vitro studies which indicate a primary role of MAO-A in the metabolism of serotonin and of MAO-B in norepinephrine degradation in primate brain. The discrepancies may reflect modulating effects of synaptic feedback mechanisms on the actions of clorgyline in vivo or perhaps a failure of CSF metabolites to adequately reflect brain amine metabolism changes. The lack of change in platelet MAO-B activity during clorgyline treatment together with the minimal changes in HVA concentrations indicate that the selective inhibitory effects of clorgyline on MAO-A were maintained during chronic administration of low drug doses.

Animals↗
PubMed1984

Neuroendocrine and behavioral effects of m-chlorophenylpiperazine administration in rhesus monkeys.

The effects of m-chlorophenylpiperazine (mCPP), a serotonin receptor agonist, on the release of plasma prolactin (PRL), growth hormone (GH), and cortisol in the rhesus monkey were studied. mCPP was administered intravenously at doses of 0.5, 1.5, and 3.0 mg/kg. GH and cortisol were increased significantly at all doses while PRL was significantly increased only following administration of 3.0 mg/kg mCPP. mCPP administration also produced behavioral alterations in each monkey, including sedation, penile erection, and defecation. PRL, GH and behavioral responses to mCPP were completely blocked by pretreatment with the serotonin antagonist metergoline (MTG). However, pretreatment treatment with MTG failed to entirely anagonize the cortisol response to mCPP. These data suggest that mCPP has prominent neuroendocrine and behavioral effects which are mediated, in part, by serotonergic mechanisms.

Animals↗
PubMed1984

Plasma prolactin changes following fenfluramine in depressed patients compared to controls: an evaluation of central serotonergic responsivity in depression.

In an attempt to evaluate the responsiveness of the serotonergic neurotransmitter system in depression, fenfluramine, a serotonin releasing agent, was administered to 18 depressed patients and 10 controls, and placebo was administered to 16 of the depressed patients in a double-blind paradigm. Plasma prolactin levels were measured prior to and for five hours following fenfluramine. Fenfluramine produced a significant increase in prolactin in both patients and controls. However, the prolactin response to fenfluramine whether measured as an absolute increase or percent increase from baseline was significantly less in depressed patients than controls. This difference remained equally statistically significant when age-and-sex-matched pairs of depressed patients and controls were compared. These results suggest that the central serotonergic system is less responsive in depressed patients than controls.

Adult↗
PubMed1984

Plasma cortisol responses to clonidine in depressed patients and controls. Evidence for a possible alteration in noradrenergic-neuroendocrine relationships.

Plasma cortisol responses to the intravenous administration of clonidine hydrochloride and placebo were evaluated in depressed patients and controls. Depressed patients had higher mean baseline cortisol levels than controls. Cortisol levels decreased during the morning study period following both placebo and 2 micrograms/kg of clonidine hydrochloride in the depressed patients, but the cortisol decrease was sixfold greater on the day of clonidine administration; these placebo-clonidine differences were statistically significant, whether calculated on an absolute decrement basis or as a percent change. In contrast, controls responded to clonidine with only a 1.5-fold greater cortisol reduction than that found after placebo, a nonsignificant difference from the day of placebo administration. Reductions in the concentration of plasma 3-methoxy-4-hydroxyphenylglycol following clonidine administration were significantly negatively correlated with baseline plasma cortisol levels, raising the possibility that abnormalities in the responsiveness of the alpha 2-noradrenergic system may be associated with the hypothalamo-pituitary-adrenal (HPA) axis dysfunction found in depressed patients.

Aged↗
PubMed1984

Biological markers in obsessive-compulsive and affective disorders.

To explore the relationship between obsessive-compulsive disorder (OCD) and affective disorder, patients with OCD were studied using a series of biological markers which have been previously reported to be abnormal in patients with affective illness. These "markers" included the dexamethasone suppression test, sleep electroencephalography, the plasma growth hormone response to clonidine, and platelet 3H-imipramine binding. Results from each of these studies suggested similarities between patients with obsessional disorder and those with affective illness. Many of these biological abnormalities were evident in obsessional patients who did not manifest depressive symptoms. As a tricyclic antidepressant, clomipramine, has been found to reduce obsessional symptoms, the relationship between these "affective-like" laboratory findings and the clinical response to clomipramine was studied in a subgroup of OCD patients. Preliminary results suggest that none of the markers studied predict clomipramine response.

Blood Platelets↗
PubMed1984

Phenylethylamine excretion in depression.

Urinary phenylethylamine (PEA) excretion was evaluated in two populations of depressed hospitalized patients. Seven of 53 patients had PEA values exceeding three times the highest value found in 16 normal controls. The patients with high PEA excretion were all females. They were not, however, otherwise clinically distinguishable from depressed patients with low PEA. In a subsample of 31 patients and 10 controls, PEA excretion was not correlated with phenylacetic acid (PAA) excretion. These results suggest that depression is not associated with a generalized PEA deficit and that PAA reductions, previously reported in a depressed patient population, may not reflect a PEA abnormality.

Adolescent↗
PubMed1984

Impaired smooth pursuit eye movement: vulnerability marker for schizotypal personality disorder in a normal volunteer population.

Impaired smooth pursuit eye movement has been proposed as a possible biologic marker for schizophrenia. Preliminary studies have suggested that this impairment may be associated with social introversion and related psychopathology in a nonpsychiatric population. To evaluate the relationship between dysfunctional smooth pursuit eye movement and schizophrenia-related psychopathology, the authors screened a new, volunteer sample of 284 male college students for eye tracking accuracy. Volunteers identified as low-accuracy trackers were significantly more likely to be diagnosed (blindly) as having a schizotypal personality disorder by DSM-III criteria than those identified as high-accuracy trackers. The authors suggest that disordered smooth pursuit eye movement may reflect a vulnerability marker for schizotypal personality disorder.

Adult↗
PubMed1984

Differential inhibitory noradrenergic responses to clonidine in 25 depressed patients and 25 normal control subjects.

The authors measured plasma 3-methoxy-4-hydroxyphenylglycol (MHPG), plasma norepinephrine, blood pressure, and heart rate responses to the alpha 2-adrenergic agonist clonidine in 25 depressed patients and 25 normal control subjects. In the control subjects clonidine reduced plasma norepinephrine, blood pressure, and heart rate significantly more than placebo. In the depressed patients clonidine reduced blood pressure and the percent fall in plasma norepinephrine but not plasma MHPG or heart rate significantly more than placebo. The absolute and percent reductions in plasma MHPG and heart rate following clonidine were significantly less than in control subjects. These results raise the possibility that the sensitivity of the alpha 2-adrenergic receptors inhibitory to noradrenergic output may be reduced in depression.

Adult↗
PubMed1984

Psychophysiological changes during pharmacological treatment of patients with obsessive compulsive disorder.

Twelve patients with obsessive compulsive disorder were studied with psychophysiological measures during a randomised, double-blind placebo-controlled drug trial. Significant clinical improvement followed six weeks of treatment with the tricyclic antidepressant clomipramine, but was not evident after an equal period of treatment with the monoamine oxidase inhibitor (MAOI) clorgyline. Compared to placebo, both drugs reduced skin conductance indices of baseline arousal, but only clomipramine reduced skin conductance and heart rate responses to loud tones and tonic and phasic skin conductance responses in a two-flash discrimination task. This suggests that reductions in autonomic responses to important and/or aversive stimuli may be critical to clinical improvement in obsessive compulsive disorder.

Adolescent↗