Immunoreactive Delta Sleep-Inducing Peptide Secretion from Mouse Dissociated, Anterior Pituitary Cells: Regulation by Corticotropin-Releasing Factor and Arginine Vasopressin

Abstract

Immunoreactive delta sleep-inducing peptide (IR-DSIP) has previously been localized to the ACTH/MSH cells of the human and porcine pituitary gland. In the present report, the distribution of IR-DSIP in the mouse pituitary gland was examined by immunocytochemistry. In this species, IR-DSIP was found to be co-localized with thyroid-stimulating hormone (TSH) in anterior pituitary thyrotrophs and was also present in nerve fibers in the posterior and intermediate lobes. The effect of synthetic DSIP on IR-ACTH release from dissociated mouse anterior pituitary cells was also studied. DSIP (>10^–9 M) inhibited both basal and CRF-induced IR-ACTH release from these cells. In addition, the effect of synthetic rat corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) on IR-DSIP secretion was investigated. CRF and AVP at concentrations of 10^–11–10^–7M inhibited release of IR-DSIP from mouse anterior pituitary cells by 63%. When CRF and AVP (10^–10–10^–7 M) were given concomitantly, the maximal inhibition of IR-DSIP release was observed at a concentration of 10^–8 M of CRF and AVP. However, these two peptides when given together showed no additive effect on IR-DSIP secretion. These findings suggest that during CRF induction of ACTH secretion from anterior pituitary corticotrophs, CRF may also act simultaneously to inhibit DSIP secretion from the thyrotrophs.

Decreased Delta-Sleep and Plasma Delta-Sleep-Inducing Peptide in Patients with Cushing Syndrome

“…a nonapeptide which has been found to have sleep-inducing and -main taining properties in several species, including humans [10][11][12][13], on the sleep parameters of patients with Cushing syndrome and normal volunteers. DSIP-like immunoreactivity (DSIP-LI) has been found in thyrotropic cells in mice [14] and corticotropic/melanotropic cells in humans and pigs [15,16], where it appeared to be colocalized with ACTH and corticotropin-like intermediate-lobe peptide (CLIP). We, therefore, hypothesized that levels of this hormone may be altered in patients with Cushing syn drome and may be related to their sleep disturbances.…”

Biosynthesis and processing of delta sleep‐inducing peptide‐like precursors in primary cultures of mouse anterior pituitary cells

“…The immunoprecipitates were washed twice in the immunoprecipitation buffer and extracted from the Sepharose beads by suspending in the SDSjPAGE treatment buffer (described below) and analyzed by SDS/PAGE. The immunoprecipitations were carried out with two previously described antisera against synthetic DSIP: one (code 7915; generated by Dr R. Ekman, Lund University) is a rabbit antiserum against DSIP coupled to bovine serum albumin and recognizes the midportion of synthetic rabbit DSIP [20]; the other (code R:5; a kind gift from Dr P. G. Vallet, Geneva, Switzerland) was raised in a rat against thyroglobulin-conjugated DSIP [I 5, 161. For control experiments, increasing concentrations (0.2 -1.25 mg/ml) of synthetic DSIP (Peninsula Labs, Belmont, CA, USA) was added to the incubation for preabsorption of the DSIP antibodies.…”

“…'s 7911 (Milab AB, Malmo, Sweden) and 7915. Both antisera have been characterized previously [20,231 and were used at a dilution of 1 :500000 and 1 :60000, respectively. Antiserum 791 1 recognizes mainly the N-terminus of DSIP while 791 5 is more specific for the midportion of the molecule.…”

“…Its occurrence at all three levels of the hypothalamic pituitary -adrenal axis [15 -181, as well as the inhibitory effect of DSIP on adrenocorticotropin secretion, both basal and stimulated by corticotropin-releasing factor [8, 201 suggest an important role of DSIP-like peptides in the regulation of this axis. Furthermore, it was shown that corticotropin-releasing factor and [Argl-vasopressin, both of which stimulate the release of adrenocorticotropin [26], inhibited the release of DSIP-like immunoreactivity from mouse anterior pituitary cells [20]. Taken together, much evidence has accumulated to indicate that DSIP-related peptide(s) produced in central neurons and in endocrine cells may function as regulatory peptide(s) besides being a sleep factor in the central nervous system.…”

“…Injection of the synthetic DSIP nonapeptide in several mammals, including man, has produced a large number of different effects, besides sleep promotion, such as improvement of stress tolerance [5, 61, regulation of the release of hypothalamic and anterior pituitary hormones [7 -111 and cardiovascular effects [6, 121. Immunocytochemical and radioimmunoassay studies have indicated the presence of DSIP-like immunoreactivity in central neurons [ 13 -161, adrenal medulla and gut [17,19,221, as well as in cerebrospinal fluid, blood, urine and milk [23 -251; it has also been found in the pituitary. In man and pig, DSIPlike immunoreactivity is stored in corticotrophs/melanotrophs [17, 181, but in the mouse anterior pituitary, it is localized to the thyrotrophs [20]. Its occurrence at all three levels of the hypothalamic pituitary -adrenal axis [15 -181, as well as the inhibitory effect of DSIP on adrenocorticotropin secretion, both basal and stimulated by corticotropin-releasing factor [8,201 suggest an important role of DSIP-like peptides in the regulation of this axis.…”