Immunoreactive Delta Sleep-Inducing Peptide in Pituitary Adrenocorticotropin/Alpha-Melanotropin Cells and Adrenal Medullary Cells of the Pig

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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.

Section: Ria O F Acth and Dsipmentioning

confidence: 87%

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

Bjartell

Castro²,

Ekman³

et al. 1989

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“…Since the first evidence of the colocalization of several neurotransmitters in single neuronal cell bodies [25], many attempts have been made to immunohistochemically demonstrate the colocalization of signal substances in the nervous systems an d /o r peripheral organs [26,27]. With regard to DSIP, recent studies have re ported the intracellular coexistence of this peptide with some regulatory' peptides in the gut, such as gastrin/CCK, secretin and PYY/glicentin [20], DSIP immunoreactivity could also be detected in noradrenaline-storing cells of adrenal medulla and ACTH/MSH cells of pituitary in several species [4,5,28].…”

Section: Discussionmentioning

confidence: 99%

“…DSIP immunoreactivity is widely distributed in biological fluids, brain and glandular system of several species [4][5][6][7][8]. Besides some sleep-promoting effects [1.…”

Section: Introductionmentioning

confidence: 99%

Light and Electron Microscopic Immunocytochemical Evidence that Delta Sleep-Inducing Peptide and Gonadotropin-Releasing Hormone Are Coexpressed in the Same Nerve Structures in the Guinea Pig Median Eminence

Charnay

Leduque

et al. 1991

The relationships between delta sleep-inducing peptide (DSIP) and GnRH immunoreactivity within the guinea pig median eminence are investigated by light and electron microscopic immunocytochemistry. Indirect immunofluorescence and elution-restaining experiments show that at the light microscopic level the distribution patterns of DSIP and GnRH immunoreactivity are indistinguishable. This suggested the possible coexistence of both immunoreactivities within the same fibers and neurosecretory endings. At the electron microscopic level, a preembedding double-immunolabeling technique using both indirect immunoperoxidase and immunogold methods, clearly indicate that DSIP and GnRH immunoreactivity are frequently colocalized within single secretory granules. In addition DSIP/GnRH immunoreactive nerve endings were also observed often in close proximity to tanycyte elements. Taken together, the present results provide for the first time ultrastructural evidence for the presence of DSIP immunoreactivity and demonstrate that DSIP and GnRH immunoreactivities may be coexpressed within the same neuronal elements in the median eminence.

“…Moreover, we could demonstrate that LH-RH and DSIP (or a closely related molecular form) are contained not only in the same axons, but also in the same ~ 100-nm dense-core vesicles, suggesting cosecretion of these peptides. [8,12], and human [9,13] brains. Its distribution pattern corresponded to that of luteinizing hor mone releasing hormone (LH-RH) [14][15][16].…”

mentioning

confidence: 99%

Colocalization of Delta Sleep Inducing Peptide and Luteinizing Hormone Releasing Hormone in Neurosecretory Vesicles in Rat Median Eminence

Vallet¹,

Charnay²,

Boura³

et al. 1991

The colocalization of immunoreactivities similar to delta sleep inducing peptide (DSIP) and luteinizing hormone releasing hormone (LH-RH) was investigated by light and electron microscopic immunocytochemistry in the rat median eminence. At the light microspic level, DSIP and LH-RH immunostained fibers, and varicosities exhibited a similar distribution pattern throughout the median eminence. Immunoreactive axons were mainly found in the lateral part of the external layer. Using an elution-restaining technique, the coexistence of LH-RH and DSIP immunoreactivities was observed in most labelled axons. To determine the intracellular localization of DSIP and LH-RH, we used double immunocytochemical labelling with species-specific antibodies and secondary antibodies conjugated to different sizes of gold particles. The two peptides were found colocalized in single axons. Immunoreactive terminals frequently showed direct membrane apposition with tanycyte processes but rare contacts with portal capillaries. No staining was observed in tanycytes and ependymal or glial elements. Moreover, we could demonstrate that LH-RH and DSIP (or a closely related molecular form) are contained not only in the same axons, but also in the same ∼ 100-nm dense-core vesicles, suggesting cosecretion of these peptides.