Plasma catecholamines and ECT

No early effects of electroconvulsive therapy on tryptophan metabolism and disposition in endogenous depression

The possibility that a single electroconvulsive therapy (ECT) could increase tryptophan (Trp) availability to the brain for 5-hydroxytryptamine (5-HT, serotonin) synthesis was examined in 10 depressed patients before and during the 1st hour following an ECT and in 4 control (minor ear, nose, and throat surgical) subjects receiving similar premedication. Trp availability to the brain, expressed as the serum Trp: competing amino acid ratio, and related aspects of Trp disposition were not significantly altered by ECT any differently than from preoperative stress and premedication. We suggest that Trp availability to the brain and, hence, cerebral 5-HT synthesis are not altered in depressed patients early after a single ECT.

Oscillometric blood pressure measurements by different devices are not interchangeable

Blood pressure (BP) is frequently measured in patients by noninvasive blood pressure (NIBP) monitors. Values obtained by oscillometric devices of different brands may appear in one patient's record as if they were interchangeable; their concordance, however, has not been established. In 25 patients with major depression who were treated with electroconvulsive therapy (ECT) BP was measured on either arm by devices manufactured by SpaceLabs (SpL, 12 patients, 182 data points) and Marquette (Marq, 13 patients, 193 data points), respectively, and comparisons were made with simultaneous measurements on the opposite arm by Dinamap 1846SX (DIN), during the awake state and at 1-min intervals up to 5-7 min after ECT. Because ECT is associated with an intense, but short-lasting hyperdynamic state, comparisons of BP values could be made over a wide range of pressures. Bland-Altman plots were constructed to show the distribution of pressure differences at all pressures. Agreements between two instruments were judged according to guide lines by the American Association for Advancement of Medical Instrumentation (AAMI). The standard deviation of the difference (SDD) between two DIN devices was 7 mm Hg for systolic (SBP) and 6.3 mm Hg for diastolic blood pressure (DBP), whereas mean differences were 0.9 and 0.2 mm Hg, respectively (P = not significant [NS]), thus showing reproducibility. Corresponding SDD values SpL versus DIN were 9.1 for SBP and 8.3 mm Hg for DBP, while the mean differences were 1.6 (P = 0.026) and 7.3 (P = 0.0001) mm Hg, respectively. Corresponding SDD values for Marq versus DIN were 11.8 and 9.7 mm Hg with mean differences of 0.8 (P = NS) and 0.3 (P = NS) mm Hg. Whereas SBP differences DIN versus DIN exceeded 10 mm Hg in only 10% of observations, they exceeded that threshold in 31% and 32% of observations for SpL versus DIN and Marq versus DIN, respectively. In view of the variability that exceeds the AAMI guidelines and the one out of three occurrence of individual SBP differences exceeding 10 mm Hg for comparisons of SpL or Marq versus DIN, measurements by these three oscillometric devices are not interchangeable.

Acute effects of single and repeated electroconvulsive therapy on plasma catecholamines and blood pressure in major depressive disorder

The role of activation of adrenergic neurons by electroconvulsive therapy (ECT) in its antidepressant action was studied by examining acute sympathetic nervous system (SNS) responses to ECT during a course of treatment in patients with melancholia. ECT had an acute dose-dependent effect on plasma norepinephrine (NE) level and blood pressure. The postictal increase in plasma NE and blood pressure was independent of electrical seizure duration. Acute levels of NE and epinephrine after ECT correlated positively with ECT dosage. No cumulative effect of repeated ECT was found on the SNS responses. ECT does activate the SNS in a dose-dependent fashion. However, alternative strategies seem necessary for studying the action of ECT on noradrenergic neurons to identify effects that are cumulative, correspond more closely to the time course of its antidepressant action, and correlate with clinical outcome.

The effect of ECT on plasma cyclic nucleotides: a simulated ECT controlled study in melancholic patients

Concentrations of cAMP and cGMP in plasma were measured in 20 drug-free melancholic patients during a simulated electroconvulsive treatment (SECT) and a bilateral ECT session. Blood samples were taken every 15 min beginning 15 min before and ending 60 min after the SECT or the ECT. Two-way ANOVA and paired t-test demonstrated a significant and greater fall in cAMP over time following SECT. ECT induced a marginal increase (P less than 0.05) at 45 min postictally. It is postulated that ECT causes an increase in cAMP levels which is masked by the decrease observed during SECT, caused presumably by the anaesthetic medication. The plasma cGMP levels were increased gradually and significantly after SECT and the same rise was observed during ECT. These effects are discussed in relation to changes in adrenergic-cholinergic activities induced by the medication and the electrical stimulus.

Effect of single and repeated electroconvulsive shock on the hypothalamic-pituitary-adrenal axis and plasma catecholamines in rats

The effects of single and repeated electroconvulsive shock (ECS) on the hypothalamic-pituitary-adrenal (HPA) axis and plasma catecholamines were studied. Rats were divided into three groups and each group received sham treatment, single ECS, or ten once-daily ECS. Jugular venous blood samples were obtained immediately before treatment and at 10, 30, 60, and 90 min following sham treatment, a single ECS or following the last of ten ECS. Plasma concentrations of corticosterone (CS), ACTH, immunoreactive beta-endorphin (ir-BE), epinephrine (E) and norepinephrine (NE) were determined. Following the single ECS plasma CS was significantly elevated at 10 and 30 min, ACTH was significantly elevated at 10, 30, and 60 min, whereas ir-BE and E peaked at 10 min and returned to basal concentration by 30 min. The concentration of plasma NE did not significantly vary at any time point. Following the tenth ECS the concentration of plasma CS revealed a significant attenuation of the increase at 10 and 30 min when compared with the CS changes observed following a single ECS. Plasma ACTH following chronic ECS was also significantly decreased in magnitude at 10, 30, and 60 min when compared with plasma ACTH levels following a single ECS. Ir-BE in plasma following ten ECS mirrored the changes following single ECS. In contrast to the attenuation of CS and ACTH following chronic ECS, the increase in peripheral catecholamines was markedly elevated after the last of ten ECS. Compared with single ECS, ten ECS produced significant increases in plasma E at 10, 30, and 60 min and at 10, 30, 60, and at 90 min for NE.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of circadian rhythm in plasma levels of 3,4-dihydroxyphenylethyleneglycol in healthy human subjects

In order to investigate the possible existence of a circadian rhythm in plasma free and sulfate-conjugated 3,4-dihydroxyphenylethyleneglycol (DOPEG), the plasma levels of this metabolite (and for comparison, of melatonin and cortisol) were measured in seven healthy volunteers at 4-h intervals over a period of 24 h. Plasma concentrations of melatonin and cortisol showed distinct diurnal variations with acrophases at 2.5 h and 8.5 h, respectively. In contrast, plasma free DOPEG levels were relatively stable over the 24-h period studied. Sulfate-conjugated and free + sulfate-conjugated DOPEG levels showed a slight, non-significant increase in the early afternoon. These results indicate that in contrast to plasma 3-methoxy 4-hydroxyphenylethyleneglycol, plasma free and conjugated DOPEG levels do not exhibit a circadian rhythm.