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Biomedical subjects

J D Coplan

Publications and source records attributed to J D Coplan.

62 records · Page 4Linked to original sources
PubMed1992

Noradrenergic function in panic disorder. Effects of intravenous clonidine pretreatment on lactate induced panic.

To assess the role of noradrenergic stimulation during lactate-induced panic, ten patients with panic disorder who panicked during a standard sodium-lactate infusion underwent a repeat infusion following intravenous clonidine pretreatment. Although clonidine significantly lowered prelactate systolic blood pressure, the drug did not significantly lower prelactate anxiety levels, as reflected by the Acute Panic Inventory (API). Clonidine blocked lactate-induced panic in four of ten subjects, a significant effect. Clonidine treatment also significantly attenuated lactate-panic symptoms, as reflected by time to panic and API comparison between trials. Nevertheless, over half the subjects still panicked in response to lactate despite clonidine. This preliminary study suggests that reduction of central noradrenergic activity by clonidine, at least at the dosage levels employed in the current study, only partially attenuates panic response to lactate. Noradrenergic theories of panic may not therefore fully account for lactate panicogenesis.

Adult↗
PubMed1992

Effects of sodium lactate infusion on cisternal lactate and carbon dioxide levels in nonhuman primates.

OBJECTIVE: To further the understanding of lactate-induced panic in patients with panic disorder, the authors examined cisternal lactate and carbon dioxide levels in nonhuman primates after infusions of sodium lactate comparable to those used in studies of human beings. METHOD: CSF and venous blood lactate, pH, PCO2, PO2, and bicarbonate were measured in five ketamine-anesthetized nonhuman primates, without mechanical ventilation, before and after they underwent infusions of sodium lactate. In addition, the same measurements were made for three of the five subjects who were given saline infusions. RESULTS: Despite the development of the characteristic peripheral biochemical effects of infused sodium lactate--increased lactate and bicarbonate levels and metabolic alkalosis--no increases in central lactate or carbon dioxide levels were observed. Saline infusions produced no biochemical effects on venous and cisternal measures. CONCLUSIONS: The results of this study are in keeping with previous findings of nonpermeability of the blood-brain barrier to anionic compounds such as lactate. They therefore support theories of lactate panic based on cognitive and/or brainstem misevaluation of peripheral somatic sensations.

Animals↗
PubMed1992

Amelioration of mitral valve prolapse after treatment for panic disorder.

Twenty panic disorder patients with mitral valve prolapse showed amelioration of prolapse on repeat echocardiogram after treatment for panic disorder. This effect was significant when compared to repeat echocardiograms in eight psychiatrically normal control subjects with mitral valve prolapse.

Adult↗
PubMed1992

Serotonin related functions in panic-anxiety: a critical overview.

The antipanic utility of imipramine and monoamine oxidase inhibitors has led to hypotheses of noradrenergic and/or serotonin (5-HT)-related abnormalities underlying panic disorder (PD) and its agoraphobic complications. Further data support significant antipanic effects for agents with acute 5-HT reuptake blockade effects. It is unlikely that ameliorative effects observed following chronic administration of 5-HT drugs remain 5-HT specific. Despite a range of recently discovered 5-HT receptor subtypes, evidence for a specific receptor abnormality in PD is lacking. Preclinical studies suggest an important role for 5-HT effects in several animal models of anxiety, including separation-induced infant protest responses and respiratory modulation. Induction of anxiety with putative 5-HT agents such as meth-chloro-phenylpiperazine and fenfluramine lend further support to 5-HT involvement in anxiety states. Critical behavioral, physiologic, and neuroendocrine differences between putative 5-HT anxiogens and "classic" panicogens, such as lactate and carbon dioxide are discussed. We propose that 5-HT agents mediate antipanic effects through amelioration of a deranged internal evaluative mechanism along cybernetic lines, rather than simple augmentation or reduction of 5-HT function.

Animals↗
PubMed1992

Behavioral effects of oral yohimbine in differentially reared nonhuman primates.

Eight unrestrained macaques were observed for 2 hours following either two oral doses of yohimbine (0.2 mg/kg and 2.0 mg/kg) or placebo administration. Four of the subjects were normally reared and four subjects had early maternal and social deprivation. In the normal subjects, yohimbine, at both doses, produced increased tension and enervation and decreased species-typical "normal" behaviors. In deprivation-reared subjects, low-dose yohimbine produced reductions in tension and enervation, and increases in "normal" behaviors. High doses of yohimbine diminished behavioral score differences between groups. The prominent increases in enervation observed in normally reared subjects suggests that yohimbine is not unequivocally anxiogenic. Moreover, early social deprivation may alter the pattern of response to yohimbine, perhaps as a result of aberrant neurodevelopment. This study reflects the role of experiential factors in determining patterns of affective response to putative anxiogenic agents.

Aging↗
PubMed1991

Dose-response effects of oral yohimbine in unrestrained primates.

Six unrestrained bonnet macaques were each observed after oral administration of four dosages of yohimbine hydrochloride (0.10, 0.25, 0.50, and 0.75 mg/kg) and a placebo. Yohimbine significantly increased episodes of motoric activation and affective response interspersed with intervals of behavioral enervation. Yohimbine scores correlated closely with baseline levels; there was no dose-response relationship. Response to oral yohimbine differed in several ways from subcutaneous and intravenous sodium lactate infusions, including prominent enervative symptoms and the appearance of sexual arousal. In light of the appearance of cyclic enervative episodes, this study suggests limitations to primate models of panic disorder utilizing oral yohimbine.

Administration, Oral↗
PubMed1990

Treatment of anxiety disorder in patients with mood disorders.

Symptoms compatible with a diagnosis of anxiety disorder frequently complicate the course of affective illness. Patients with depression may have panic attacks, phobias, severe social anxiety, obsessions, compulsions, and generalized anxiety. If the affective disorder is the primary condition, its treatment should be sufficient in most instances to relieve the concomitant anxiety symptoms. Thus, judicious choice of antidepressant therapy for treatment of major and atypical depression will usually resolve associated panic attacks, generalized anxiety, phobias, and compulsions. It must be recalled, however, that antidepressant therapy usually takes between 4 and 6 weeks to have full clinical effect; in the interim, anxiety symptoms may be the most troubling and disabling aspect of the illness. Therefore, using antianxiety agents in treating depressed patients who also have anxiety symptoms is often recommended while waiting for the antidepressant to work. Benzodiazepines are extremely useful for short-term treatment of most anxiety symptoms in depressed patients. The dose should be kept to the lowest possible to relieve symptoms, and the medication should be tapered and then discontinued once the underlying affective disturbance is relieved. Buspirone is also very effective in treating generalized anxiety disorder and may be used in conjunction with antidepressants of most classes. A wide range of behavioral and cognitive techniques may also help relieve anxiety symptoms in the depressed patient.

Antidepressive Agents↗