ABSTRACT
BACKGROUND: The beneficial effect of antidepressant interventions has been proposed to depend on suppression of rapid eye movement (REM) sleep or inhibition of electroencephalographic (EEG) slow-wave activity (SWA) in non-REM sleep. Use of the monoamine oxidase inhibitor phenelzine sulfate can eliminate REM sleep. We studied the relation between REM sleep suppression and antidepressant response and the effect of phenelzine therapy on sleep EEG power spectra. METHODS: Open-labeled prescriptions of 30 to 90 mg of phenelzine were given to 11 patients with major depressive disorder (6 men and 5 women; mean age, 41.4 years); all were physically healthy. Mood, dream recall, sleep, sleep EEG, and ocular and muscular activity during sleep were studied before treatment and during the third and fifth weeks of pharmacotherapy. RESULTS: Six patients remitted from depression, 2 responded partially, and 3 showed no antidepressant response. Independent from clinical response, REM sleep was dramatically suppressed. On average, only 4.9 minutes of REM sleep was observed in treatment week 5, and it was completely absent in 6 patients. This effect was compensated for by increased stage 2 sleep. In non-REM sleep, EEG power was higher than at baseline between 16.25 and 25 Hz. Slow-wave activity (power within 0.75-4.5 Hz) and the exponential decline of SWA during sleep were not affected. CONCLUSIONS: Antidepressant response to phenelzine treatment does not depend on elimination of REM sleep or inhibition of SWA in non-REM sleep. In depressed patients, REM sleep is regulated independently from non-REM sleep and can be manipulated without altering the dynamics of SWA.
Subject(s)
Depressive Disorder/drug therapy , Electroencephalography/drug effects , Monoamine Oxidase Inhibitors/therapeutic use , Phenelzine/therapeutic use , Sleep/drug effects , Adult , Affect/drug effects , Affect/physiology , Depressive Disorder/diagnosis , Dose-Response Relationship, Drug , Dreams/drug effects , Dreams/psychology , Electroencephalography/statistics & numerical data , Female , Humans , Male , Mental Recall/drug effects , Mental Recall/physiology , Middle Aged , Monoamine Oxidase Inhibitors/administration & dosage , Monoamine Oxidase Inhibitors/pharmacology , Phenelzine/administration & dosage , Phenelzine/pharmacology , Sleep/physiology , Sleep, REM/drug effects , Sleep, REM/physiology , Treatment OutcomeABSTRACT
The nucleotide sequence of a Salmonella typhimurium DNA segment of 549 base pairs which encompasses the operator-promoter of the pts operon, the entirety of the ptsH gene, encoding HPr of the phosphotransferase system (PTS), the first 29 nucleotides of the ptsI gene, encoding Enzyme I of the PTS, and the intercistronic region between the ptsH and ptsI genes was determined and compared with the corresponding sequence from Escherichia coli (De Reuse et al., 1985). The two sequences showed 91% overall identity, with some regions showing sequence conservation and others exhibiting relative divergence. Two open reading frames were identified in both species: one encoded HPr on the 'sense' strand (255 nucleotides; 12 nucleotide differences, no amino acid differences); the other, on the anti-sense strand, consisted of 291 nucleotides (13 nucleotide differences, 13 amino acid differences). While HPr bears a net negative charge, the putative protein encoded by the open reading frame on the anti-sense strand is strongly basic. Computer analyses of HPr proteins from five different bacterial genera revealed four regions which show strong sequence identity and therefore are presumed to be critical for maintenance of biological activity. Two of these regions were specific to Gram-positive bacteria. Proposed functions for each of these regions are discussed. Relative evolutionary distances between the HPr proteins were also computed.
