Disease relevance of Vip

• Vasoactive intestinal polypeptide antiserum affects rat prolactin mRNA in 40-day but not 110-day diethylstilbestrol-induced prolactinoma tissue [1].
• To elucidate the role of VIP in this context, lactotroph hyperplasia was induced in female Fisher 344 rats by implanting sc pellets of diethylstilbestrol (DES) [2].
• Less than 1% of FG-labeled neurons were immunoreactive for VIP in this ganglion [3].
• Neuroblastoma cells also produce other neuropeptides, among them vasoactive intestinal polypeptide (VIP) [4].
• Infusion of rat VIP (25 pmol/min) failed to affect GMBF and mean arterial blood pressure, whereas a fivefold higher dose of VIP (125 pmol/min) led to a significant rise of GMBF and to significant hypotension [5].

Psychiatry related information on Vip

• In rats, rapid eye movement (REM) sleep can be elicited by microinjection of vasoactive intestinal polypeptide (VIP) into the oral pontine reticular nucleus (PnO) [6].
• Motor activity of vascularly perfused rat duodenum. 2. Effects of VIP, PACAP27 and PACAP38 [7].
• However, both VP and VIP contribute to the regulation of the amount of time spent in sleep and wakefulness and the level of VP in the CSF is correlated with the amplitude of the rhythm [8].

High impact information on Vip

• In addition, we have observed by both light and electron microscopy that some VIP- and some ChAT-positive structures in cortex are closely associated with blood vessels [9].
• Vasoactive intestinal polypeptide (VIP) is present in high concentrations in the cerebral cortex, where it is the putative neurotransmitter of a major intracortical neuronal system [10].
• Homogenates of cortical tissue contain high-affinity, specific binding sites for VIP as well as an adenylate cyclase system which is sensitive to this peptide [10].
• As with many of the other peptidergic systems which have been identified in the central nervous system (CNS), it has proved extremely difficult to elucidate the nature and extent of the functional role of VIP in specific brain areas [10].
• VIP occurs in intrathyroidal nerves and stimulates thyroid hormone secretion [11].

Chemical compound and disease context of Vip

• VIP- and, to a lesser extent, NPY-IRs are found in numerous neuronal cell bodies and in nerve fibers; GRP-IR is present in numerous nerve processes and in few cell bodies; CGRP- and SP/TK-IRs are detected only in fibers wrapping around unlabeled ganglion cells [12].
• Energy metabolism in rat pituitary tumors during stimulation of prolactin by vasoactive intestinal polypeptide and thyrotropin-releasing hormone: a study with nuclear magnetic resonance spectroscopy [13].
• The signal transduction pathway mediating VIP- and PACAP-induced potentiation of nicotinic ACh-evoked currents involves a pertussis toxin (PTX)-sensitive G-protein [14].
• The concentration of vasoactive intestinal polypeptide (VIP) in the anterior pituitary gland of female rats was significantly reduced by pituitary implants, prolactin-secreting tumours or dopamine blockade-induced hyperprolactinemia [15].
• To determine whether thyroid hormone alters VIP biosynthesis in the PVN, we studied the effect of hypothyroidism on the content of immunoreactive (IR)-VIP and VIP mRNA in PVN neurons using histochemical techniques [16].

Biological context of Vip

• Results from this experiment reveal partial immunoneutralization of intrapituitary VIP significantly decreased PRL secretory rate by rapid reduction in rRPL mRNA in the 40-day tumors [1].
• When a DNA plasmid containing multiple copies of the CRE was injected into newly cultured sensory neurons to sequester transcription factors binding the endogenous CRE, there was a selective reduction in VIP expression [17].
• VIP induction in sensory neurons therefore probably results from transcriptional activation by c-Jun acting in combination with other factor(s), possibly acting through the CRE [17].
• Marked, prolonged tachyphylaxis to NPY and VIP was observed following brief exposure to these peptides [18].
• Both PACAP and VIP had little effect on phosphoinositide hydrolysis in these cells [19].

Anatomical context of Vip

• The entire VIP nerve fiber population was found to also contain PHI [20].
• In the somatolactotrope GH4C1 cell line, we have previously identified crosstalk between the MAPKinase cascade ERK1/2 and the cAMP/protein kinase A pathway after the activation of the VPAC2 receptor by vasoactive intestinal polypeptide (VIP) or pituitary adenylyl cyclase-activating polypeptide (PACAP38) [21].
• About half of the labeled nerve cell bodies in the sphenopalatine and otic ganglia contained VIP [22].
• To elucidate the structural domains involved in a selectivity for VIP binding and the subsequent receptor activation, a series of chimeric receptors between the VIP and PACAP receptors was constructed, expressed in COS-7 cells, and analyzed for ligand binding and cAMP generation [23].
• Rhythmic secretion of prolactin in rats: action of oxytocin coordinated by vasoactive intestinal polypeptide of suprachiasmatic nucleus origin [24].

Associations of Vip with chemical compounds

• Release of oxytocin and vasopressin by intracerebroventricular vasoactive intestinal polypeptide [25].
• Vasoactive intestinal polypeptide (VIP) content is increased in the hyperplastic pituitaries of estrogen (E)-treated rats, thus suggesting that this neuropeptide could mediate the E effect on lactotrophs [2].
• DES treatment also increased pituitary VIP content and VIP mRNA levels, but not in the hypothalamus and cerebral cortex [2].
• Retinal lesion of photoreceptors resulted in increased tissue levels of all measured neuropeptides except SP in the hypothalamus and increased VIP in the ventral tegmental area/substantia nigra [26].
• A small population (1% of submucosal plexus neurons) containing vasoactive intestinal polypeptide- and peptide histide isoleucine-like immunoreactivity without NPY-like immunoreactivity was also observed [27].

Physical interactions of Vip

• This suggests that there is a nonbiologically relevant high affinity VIP-binding site within the rat PACAP receptor [23].
• The observed overlap in the distributions of NPY- and VIP-immunoreactive fibers in these glands further suggests that NPY may interact with VIP to stimulate secretion [28].

Co-localisations of Vip

• Some VIP-like immunoreactive nerves were shown to be co-localized with acetylcholinesterase-positive cholinergic nerves [29].
• In some fibres, which seem to originate in the local paracervical ganglia, PACAP was co-localized with vasoactive intestinal polypeptide [30].

Regulatory relationships of Vip

• Vasoactive intestinal polypeptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) receptors are closely related G protein-coupled receptors with seven-transmembrane domains [23].
• Neurosecretory OT cells of the hypothalamic paraventricular nucleus that express VIP receptors were identified by using immunocytochemical techniques in combination with the retrogradely transported neuronal tracer Fluoro-Gold (iv injected) [24].
• Antisera to vasoactive intestinal polypeptide inhibit basal prolactin release from dispersed anterior pituitary cells [31].
• NPY induced contractions were significantly (p less than 0.01) weaker (lower Emax) in SAH as compared to control rats while the relaxant responses to ACh and VIP were slightly increased after SAH [32].
• Vasoactive intestinal polypeptide stimulates cholecystokinin secretion in perfused rat duodenum [33].

Other interactions of Vip

• The cAMP responses of these receptors generally correlated with the ability of VIP to compete for PACAP radioligand binding with the exceptions for some particular chimeras [23].
• The most dramatic change in expression occurred for GAL, NPY and VIP mRNAs which all rose rapidly (day 3) from non-detectable levels [34].
• These observations suggest a central site of action for VIP in OT and AVP release, probably in the hypothalamus [25].
• NC/CB, NC/CR and NC/VIP double-labeled cells were found in all hippocampal regions, and represented 29%, 24% and 18% of the NC-IR cells, respectively [35].
• Somatostatin, ENK and VIP were found to be the most dense in the dorsal PBL [36].

Analytical, diagnostic and therapeutic context of Vip

• Vasoactive intestinal polypeptide (VIP)- and peptide histidine-isoleucine (PHI)-IR fibers in hypophysectomized animals had already contacted portal vessels 5 d after hypophysectomy, and from then on progressively increased in numbers [37].
• Regulation of VIP and other neuropeptides by c-Jun in sensory neurons: implications for the neuropeptide response to axotomy [17].
• We blocked c-Jun synthesis by microinjecting antisense oligonucleotides and found that VIP expression, determined by quantitative immunofluorescence, was specifically reduced [17].
• Since in vitro electrophoretic mobility shift assays showed that a nominal cyclic AMP responsive element (CRE) associated with the rat VIP gene could bind c-Jun-containing transcription factor complexes, we next investigated whether VIP expression in sensory neurons might depend on transcription factor binding to the CRE [17].
• Using double immunohistochemistry, with VIP as a marker for intrinsic innervation and calcitonin-gene related peptide (CGRP) as a marker for mainly extrinsic innervation, the distribution and localization of PACAP were studied in the rat pancreas [38].

References