The influence of synthetic DSIP (delta-sleep-inducing-peptide) on disturbed human sleep

Distribution and colocalization of delta sleep inducing peptide (DSIP) with corticotropin-like intermediate lobe peptide (CLIP) in the human hypophysis

DSIP and CLIP [ACTH(18-39)] immunoreactive (IR) neurons and fibers were examined in the human hypophysis and pituitary stalk using immunmohistofluorescence and peroxidase-antiperoxidase methods. Double-stained and adjacent stained sections demonstrate that DSIP is colocalized in about 75% of CLIP-IR-like cells in the anterior pituitary and in residual intermediate lobe cells. Only few CLIP-IR-like fibers are observed in the posterior lobe. On the contrary, a high density of DSIP-IR fibers is visualized in the stalk. It is suggested that DSIP acts as a sleep promoting factor (one of many other actions) and that CLIP increases the paradoxical sleep, so that these two peptides could play a role in the regulating system of the sleep-waking cycle.

Evidence for a role of delta sleep-inducing peptide in slow-wave sleep and sleep-related growth hormone release in the rat

To examine the role of delta sleep-inducing peptide (DSIP) in sleep-related growth hormone (GH) release, male rats were deprived of sleep for 4 hr by placing them on a slowly rotating wheel. Sleep deprivation by this method caused a significant increase in GH release, as indicated by the increase in plasma GH concentrations (P less than 0.01), and also in the amount of slow-wave sleep (SWS) (P less than 0.001) above initial values after removal of the animals from the rotating wheel. These increases were blocked by microinjection into the third cerebral ventricle of highly specific antiserum to DSIP. In control rats receiving an equal volume of normal rabbit serum, the significant increase in plasma GH as well as SWS remained after removal of the rats from the wheel. The increased release of endogenous DSIP in the sleep-deprived animals may have caused an increase in SWS as well as plasma GH. Since DSIP increases plasma GH after its injection into the third cerebral ventricle and since passive immunization against DSIP blocks the increase in SWS and GH release that follows the 4 hr of sleep deprivation, the results suggest that DSIP can be a physiological stimulus for sleep-related GH release as well as for the induction of SWS.

Delta sleep-inducing peptide (DSIP) stimulates growth hormone (GH) release in the rat by hypothalamic and pituitary actions

To evaluate possible effects of delta sleep-inducing peptide on GH release, the peptide was micro-injected into conscious animals with third ventricular cannulae and blood samples were drawn from indwelling external jugular vein cannulae. Ovariectomized animals were used in order to eliminate gonadal steroid feedback. In the initial experiment, intraventricular injection of 5 micrograms of the peptide induced an elevation of GH which became significant by 30 min and persisted for the 120 min duration of the experiment after the injection. Diluent-injected animals showed a slight initial drop in GH and then no increase. The increase in plasma GH induced by the peptide was dose-related with a minimal effective dose of 0.1 microgram and a linear log-dose increase to a dose of 10 micrograms. This effect is presumably mediated hypothalamically via a dopaminergic mechanism since it could be blocked by pre-treatment of the animals with pimozide, a dopamine receptor blocker. Dispersed overnight, cultured pituitary cells from ovariectomized rats exhibited a dose-related increase in GH release in static incubations with DSIP. A response occurred with the lowest dose tested (10(-12) M) which increased to a maximum at 10(-10) M DSIP. The responses then declined at higher doses such that they were no longer significant at doses of 10(-7) and 10(-5) M. The increase even at the most effective dose was approximately 50% above the basal values. The results are consistent with the hypothesis that DSIP may be involved in GH release via a dopaminergic mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Delta-sleep-inducing peptide (DSIP): a review

Since the turn of the century, it has been postulated that humoral factors induce sleep. Many compounds were proposed as sleep-factors, but only two of the sleep-peptides have been purified to homogeneity and characterized, so far. One of them, DSIP, was shown to be a nonapeptide of MW 849 and to induce mainly delta-sleep in rabbits, rats, mice, and humans, whereas in cats, the effect on REM sleep was more pronounced. A U-shaped activity curve was determined for the dose as well as for the time of infusion. DSIP-like material was found by RIA and immunohistochemistry in brain and by RIA in peripheral organs of the rat as well as in plasma of several mammals. In addition to sleep, the peptide also has been observed to affect electrophysiological activity, neurotransmitter levels in the brain, circadian and locomotor patterns, hormonal levels, psychological performance, and the activity of neuropharmacological drugs including their withdrawal.

Localization of neurons containing immunoreactive delta sleep-inducing peptide in the rat brain: an immunocytochemical study

Delta sleep-inducing peptide has been found in the peripheral circulation of animals entering slow-wave, or delta, sleep. An antiserum to this peptide was used to localize immunoreactive-like delta sleep-inducing peptide in the rat brain. The peptide was shown to have a rather widespread distribution. In the forebrain, the majority of these neurons were found to extend in a continuous rostral-caudal band in the ventral one-third of the brain from the primary olfactory cortex to the lateral hypothalamus. Neurons were also present in the basal ganglia, amygdala, septum, and thalamus. In the brainstem, the neurons were widespread and associated with the reticular formation, raphe nuclei, nuclei of the trigeminal complex, several auditory nuclei--nuclei of the lateral lemniscus, cochlear nuclei, and inferior colliculus--, cerebellum, locus ceruleus, periventricular gray, and vagal and hypoglossal nuclei. Immunoreactive fibers were, in general, difficult to demonstrate; they were seen mainly in the vicinity of the third ventricle and near blood vessels. The function of delta sleep-inducing peptide is unknown and its role in sleep is still under investigation. The distribution of delta sleep-inducing peptide in the present study suggests that the peptide is a component of several systems--arousal, locomotion, auditory, visual and sensory--both somatic and vestibular. The widespread distribution of the peptide, the lack of demonstrable immunoreactive fiber tracts, and the presence of these neurons in areas known to contain aminergic and peptidergic neurons, raises the possibility that neurons containing delta sleep-inducing peptide may exert their effect by projecting directly into blood vessels and/or interacting with neurons in their immediate vicinity.

Sleep disturbances in a case of brain-stem lesions; pharmacological study

A pharmacological study was carried out of a case of severe insomnia following brain-stem lesions; several polygraphic controls were used. Initially total duration of sleep was brief (less than 4 h) with a high REM/NREM ratio and a short paradoxical sleep (PS) latency. In addition, periodic breathing and tremor were observed. Slow injection of delta-sleep-inducing peptide (DSIP) improved sleep both quantitatively and qualitatively, although PS latency remained short. These effects were reversible. The effects of 5-HTP + benzerazide, of L-DOPA + benzerazide (Modopar) and of clonazepam (Rivotril) were compared.

Autoradiographic localization of binding sites for the delta sleep-inducing peptide ( [3H]DSIP) on neurons of cultured rat brainstem

Binding of the delta sleep-inducing peptide (DSIP) was studied in cultures of rat brainstem by means of autoradiography. Binding sites for [3H]DSIP were observed on small, medium-sized and large brainstem neurons but not on glial cells. Addition of unlabeled DSIP inhibited or markedly reduced binding of [3H]DSIP. It is suggested that brainstem neurons might possess receptors for this sleep-inducing peptide.

Insomnia: I. Classification, assessment and pharmaceutical treatment

Insomnia is a public health problem because of its high prevalence, the risk of hypnotic drug abuse, and self medication combined with alcohol and other nonprescription chemicals. Clinical experience has given rise to a descriptive classification of the insomnias many of which are secondary to medical disease. The information now available allows us to suggest a systematic approach to the assessment of insomnia emphasizing its history, events associated with sleep onset, observable behaviour and experience associated with interruptions in sleep. This paper attempts to organize the present state of knowledge in a format that can be taught to general physicians who deal with the most insomnia patients.

Amphetamine-induced locomotor behavior of mice is influenced by DSIP

The delta sleep-inducing peptide (DSIP) has been shown to induce effects other than only delta sleep. One of these effects was the paradoxical thermoregulatory and locomotor response of rats to amphetamine after DSIP administration. In the present investigation we found similar effects of DSIP on the locomotor activity in mice. However, two different doses of DSIP (30 and 120 nmol/kg) and 3 doses of amphetamine (4, 10, and 15 mg/kg) produced a complex pattern of effects in mice tested at 22 degrees C. In general, DSIP-treated mice showed lower locomotor activity after amphetamine than controls, but under two conditions, both using 15 mg/kg amphetamine, DSIP produced higher scores; this occurred in the first two hours after amphetamine for the 30 nmol/kg DSIP group and in the third hour for mice given 120 nmol/kg DSIP. The results indicate that the effects of DSIP on locomotor behavior were dependent on the dosage of the peptide and the time of measurement as well as the level of amphetamine stimulation.

DSIP/DSIP-P and circadian motor activity of rats under continuous light

Daily intravenous injection of 30 nmol/kg DSIP (delta sleep-inducing peptide) in rats under constant illumination produced marked changes of their motor activity as compared to saline controls. Similar marked but distinctly different effects on the circadian pattern of locomotor behavior partially abolished by constant illumination were also obtained after repeated administration of 0.1 nmol/kg DSIP-P (the phosphorylated analogue of DSIP) which enhanced overall motor activity. In both instances the results additionally differed from those reported for a normal 12 hr light:dark cycle. The present results support the hypothesis that DSIP might primarily act by influencing circadian rhythmicity.