Cinzia Arancio

Pharmacologic effect of imipramine, paroxetine, and sertraline on 35% carbon dioxide hypersensitivity in panic patients: a double-blind, random, placebo-controlled study.

The effects of short treatment (7 days) with the tricyclic antidepressant imipramine and the two selective serotonin reuptake inhibitors paroxetine and sertraline on the reactivity to inhalation of 35% CO2/65% O2 were compared in 70 panic patients who had positive responses to 35% CO2 inhalations. A double-blind, random, placebo-controlled design was applied. Each patient was given the 35% CO2 challenge on days 0 (before starting the treatment), 3, and 7. In the placebo group, there were no significant changes in the reactivity to 35% CO2 in the three sessions whereas there were significant similar reductions of reactivity to 35% CO2 in all three drug-treated groups. These results confirm the good reproducibility of 35% CO2 reactivity and the negligible effects of placebo on reactivity to CO2 and suggest that short treatments with imipramine, paroxetine, and sertraline decrease reactivity to 35% CO2, possibly as an expression of their antipanic properties.

Plasma Interleukin-1β and Tumor Necrosis Factor Concentrations in Obsessive–Compulsive Disorders

Plasma interleukin-1 beta (Il-1 beta) and tumor necrosis factor-alpha (TNF-alpha) concentrations were measured twice, at a 48-hour interval, in 27 drug-free obsessive-compulsive patients (12 women and 15 men) and in 27 sex-age-matched healthy controls. Il-1 beta and TNF-alpha concentrations were significantly lower in patients than in controls, whereas there were no differences in either group between men and women, between the samples of the two days, or, in the patients, between those who had and those who had not been previously treated with psychopharmacologic drugs.

Dopamine function in obsessive—compulsive disorder: Growth hormone response to apomorphine stimulation

Indirect observations suggest that the dopaminergic system may be involved in the pathophysiology of obsessive-compulsive disorder (OCD). The dopaminergic function of 15 patients with OCD and 15 age/sex-matched controls was evaluated by measuring the growth hormone (GH) responses to stimulation with the dopaminergic agonist apomorphine (APO), which increases growth hormone-releasing hormone (GHRH), GH, and somatomedine C (SMD-C) secretions. Therefore, we measured basal plasma GH and SMD-C concentrations and GH responses to GHRH stimulation to exclude that a downstream pathology of the somatotropic axis could obscure the significance of the results of the APO test. The response of prolactin (PRL) to APO inhibition were also measured. Basal plasma levels of GH, SMD-C, and PRL, GH responses to GHRH stimulation, and PRL responses to APO inhibition did not differ in the two groups of subjects. GH responses to APO stimulation were blunted in obsessive-compulsive (OC) patients. The emetic response to the same stimulation was stronger in patients than in controls. These responses suggest that in our OC patients there is a dysregulation of the dopaminergic system, which is possibly expressed in different ways in the various areas of the central nervous system.

Menstrual cycle-related sensitivity to 35% CO2 in panic patients

In a double blind, random, cross-over design, 10 patients and seven controls inhaled one vital capacity of 35% CO2-65% O2 during their early-follicular and midluteal phases. Anxiety after CO2 intake was significantly stronger in the early-follicular phase than in the midluteal phase for patients. Controls had no anxiety reactions.

Pharmacologic effect of toloxatone on reactivity to the 35 % carbon dioxide challenge : a single-blind, random, placebo-controlled study

The effect of a short treatment (7 days) with the reversible monoamine oxidase type A inhibitor toloxatone on the reactivity to the inhalation of 35% CO2 was evaluated in 18 panic patients who responded to 35% CO2 inhalation with panic before treatment. A single-blind, placebo-controlled design was applied. Panic patients were randomly assigned to the toloxatone (N = 10) or placebo (N = 8) groups and were given the 35% CO2 challenge on days 1 (before starting the treatment), 3, and 7. Patients on placebo did not report any significant changes in their reactivity to 35% CO2 during the three sessions, whereas patients on toloxatone reported a significant attenuation of the reactivity on day 7. These results indicate that (1) anxiety provoked by the inhalation of 35% CO2 is reproducible; (2) placebo has a negligible effect on 35% CO2 reactivity; and (3) reactivity to 35% CO2 is significantly attenuated by short treatment with toloxatone, possibly related to its antipanic activity.

Noradrenergic receptor sensitivity in obsessive-compulsive disorders: I. Growth hormone response to clonidine stimulation

In 15 patients with obsessive-compulsive disorder (OCD) and in 15 healthy controls postsynaptic alpha-2-adrenoceptor sensitivity was examined by measuring the growth hormone (GH) response to growth hormone-releasing hormone (GHRH) and to clonidine stimulation. Basal values of GH and somatomedin-C (SMD-C) and mean GH responses to GHRH were the same in patients and controls, thus suggesting that a peripheral pathology of the somatotropic axis should not be present. GH responses to clonidine stimulation were blunted in patients suggesting that post-synaptic alpha-2-adrenoceptors are subsensitive, possibly due to higher than normal noradrenergic secretion.

Comparison of 35% carbon dioxide reactivity between panic disorder and eating disorder

Patients with panic disorder (PD) are hyperreactive to carbon dioxide (CO(2)), but the specificity of this characteristic to PD is controversial. Anxiety and phobic symptomatology are common to both panic and eating disorders (ED). To investigate the specificity of CO(2) hyperreactivity to PD, the responses to inhalation of a 35% CO(2) and 65% oxygen (O(2)) gas mixture were assessed. Reactions to 35% CO(2) challenge were compared among three groups of age- and sex-matched subjects: 14 patients with ED, 14 patients with PD, and 14 healthy controls (HC). A double-blind, randomized, crossover design was used. Only patients with PD showed a strong reaction to 35% CO(2), while patients with ED and HC did not react significantly. The results support the specificity of CO(2) hyperreactivity to PD.

Neurotransmitter and Hormonal Background of Hostility in Anorexia nervosa

Marked hostility toward relatives, therapists and friends is very frequently observed in anorexia nervosa (AN) as expression of outward-directed aggressiveness which interferes with the therapeutic programs of the patients. With the purpose to investigate this aspect of the disorder and its biological background, we studied in anorexics some neurotransmitter-hormonal secretions which are known to modulate aggressivity-hostility by measuring plasma concentrations of total (TT) and free testosterone (FT), total estrogens (TE), the TT/E and FT/TE ratios, and the serotonergic function by measuring basal prolactin (PRL) levels and responses to stimulation with the specific serotonin (5-HT)-releasing agent D-fenfluramine (D-Fen). In 13 women with AN, 5 of the restricted (AN-R) and 8 of the bingeing/purging type (AN-BP) in an active phase of the disease, and in 13 healthy controls matched for sex and age, we measured hostility by the SCL-90 scale (subscale items 11, 24, 63, 67, 74, 81). Basal TT, FT, TE, TT/TE, FT/TE, PRL values and PRL responses to D-Fen and to saline administration were measured radioimmunologically in AN patients and controls. Hostility was significantly higher in AN patients than in controls, TT, FT and TE concentrations were significantly lower in AN patients than in controls, TT/TE ratio was significantly higher in AN patients than in controls, and FT/TE ratio was not different in the two groups. In AN patients and controls, hostility correlated positively with TT and FT values. Basal PRL values and responses to D-Fen administration were significantly lower in anorexics than in controls, but they did not correlate with the degree of hostility in either patients or controls. In conclusion, hostility is higher than normal in anorexics, and its severity seems to be linked to the secretion of FT and not to the alterations in the 5-HT function.

Growth hormone response to growth hormone-releasing hormone stimulation in obsessive–compulsive disorder

Two groups of 30 patients with obsessive-compulsive disorder and 30 age- and sex-matched healthy control subjects were given a growth hormone-releasing hormone (GHRH) stimulation test to determine: (1) whether the downstream function of the somatotropic axis (growth hormone = GH, somatomedin-C = SMD-C) was impaired; (2) what might be the central alteration responsible for such impairment; and (3) whether alterations might be linked to the etiopathogenesis of the disease. Basal values of GH and SMD-C were the same in patients and control subjects, but GH responses to GHRH stimulation were significantly lower in patients than in control subjects. The absence of a pathology of basal GH and SMD-C concentrations indicates that the blunted GH responses to GHRH stimulation are not due to a negative feedback mechanism and suggests that a central neurotransmitter-neuropeptide pathology might be involved in the phenomenon.