Distribution Of Vasoactive Intestinal Polypeptide Research Articles

Evidence for and significance of the projection of VIP neurons from the myenteric plexus to the taenia coli in the guinea pig

Immunohistochemical studies of the distribution of vasoactive intestinal polypeptide were made in the cecum from normal guinea pigs and from guinea pigs after lesions of the cecal wall had been made. These experiments were designed to determine the origin of the vasoactive intestinal polypeptide axons which supply the taenia of the cecum in order to ascertain whether the projections of the vasoactive intestinal polypeptide neurons were consistent with VIP being contained in enteric inhibitory neurons. Vasoactive intestinal peptide was found in nerve cell bodies of both the myenteric and submucous plexuses. After severing connections between the taenia and the myenteric plexus the vasoactive intestinal polypeptide fibers in the taenia disappeared, but there was no effect on these fibers if the taenia was separated from the submucous plexus or surrounding muscle while leaving connections with the myenteric plexus intact. Retrograde degenerative signs were seen in VIP fibers and nerve cell bodies of the myenteric plexus after removal of the taenia. In conclusion, VIP is contained in neurons that have the same projections as the enteric inhibitory neurons from the myenteric plexus to the taenia of the cecum.

Localization of vasoactive intestinal polypeptide and neurotensin immunoreactivities in the avian retina.

The distribution of vasoactive intestinal polypeptide (VIP)- and neurotensin (NT)-like immunoreactivities in the chicken retina was investigated by immunohistochemistry. VIP- and NT-positive cells were found throughout the chicken retina. The majority of them were located in the proximal portion of the inner nuclear layer and the processes from these cells directed to the inner plexiform layer where they ramified, suggesting that VIP- and NT-positive cells located in this region probably are amacrine cells.

Immunohistochemical studies of the enteric nervous system in tissue culture and in situ: Localization of vascoactive intestinal polypeptide (VIP), substance-P and enkephalin immunoreactive nerves in the guinea-pig gut

Immunofluorescence methods have been used to determine the detailed distribution of vasoactive intestinal polypeptide (VIP), substance-P and enkephalin nerve fibres in fixed cryostat sections from guinea-pig duodenum, jejunum, ileum, caecum at the site of the taenia coli, and proximal and distal colon. A novel method is used involving immunostaining of tissue culture preparations of both myenteric and submucous plexuses. These preparations allow each plexus to be studied in isolation from all axonal input for the first time, since they provide unequivocal extrinsic denervation together with severance of any intrinsic connections between the plexuses. In tissue sections the most prominent sites of VIP and substance-P immunoreactive fibres are the ganglia of the myenteric and submucous plexuses, the circular muscle layer and the longitudinal muscle of the taenia coli. In addition, VIP is prominent in the lamina propria of the submucosa except in the caecum. Enkephalin-immunopositive fibres are restricted to the ganglia of the myenteric plexus, the circular muscle layer and the longitudinal layer of the taenia coli. The culture preparations reveal that intrinsic ‘VIP neurons’ are common in the submucous plexus of the caecum and colon. They are also present, but in much lower numbers, in the myenteric plexus of the small intestine and colon but are not found in the myenteric plexus of the caecum. Intrinsic ‘substance-P neurons’ are present in the myenteric plexus from the small intestine, caecum and colon as well as in the submucous plexus of the colon; intrinsic ‘substance-P neurons’ are not found in the submucous plexus of the caecum. ‘Enkephalin neurons’ are numerous in the myenteric plexus of the small intestine, caecum and colon but are absent from the submucous plexus. Immunoreactivity is compared in the normal and denervated caecum by both the histochemical method and by radioimmunoassay of tissue extracts. In conjunction with the studies on tissue cultures, the results provide evidence for intrinsic reciprocal connections between the myenteric and submucous plexus of the caecum by neurons containing VIP and substance-P. An extensive comparison of these results with data from functional studies shows that the distribution of VIP, substance-P and enkephalin fibres in the gut is broadly in agreement with present knowledge of the action of these peptides on gut tissue, if it is assumed that they function as neurotransmitters or neuromodulators. In some instances, however, peptide-containing fibres and pathways are found which do not correlate with present knowledge obtained from functional studies. These observations provide new clues to the role of peptide neurons in gut function.

Vasoactive intestinal polypeptide (VIP) in mouse and rat brain: An immunocytochemical study

Immunoperoxidase technique and light microscopy were used to investigate the distribution of vasoactive intestinal polypeptide (VIP) in mouse and rat brain. Both 50 μm unmounted cryostat and 6 μm deparaffinized sections were studied in coronal or sagittal plane. At least 4 different major VIP systems were found: (1) an intracerebral cortical system; (2) one innervating the central amygdala and nucleus of the stria terminalis; (3) a pathway originating in the suprachiasmatic nucleus of the hypothalamus; and (4) another originating in the central grey of the midbrain. Specific cell body staining was seen in the limbic and neocortex, in the basal-caudal portion of the suprachiasmatic nucleus of the hypothalamus, and in the central grey of the midbrain. Heavy terminal field patterns were noted in the suprachiasmatic nucleus, central amygdaloid nucleus, bed nucleus of the stria terminalis and nucleus accumbens. Fiber density was moderate in the tuberculum olfactorium, anterior hypothalamus including the medial preoptic area, mediobasal hypothalamus (especially dorsomedial region), periventricular thalamus, lateral lemniscal system, parabrachial nucleus, nucleus solitarius, and area postrema. Fibers could be traced dorsally from the suprachiasmatic nucleus to the dorsomedial and paraventricular nuclei of the hypothalamus and the periventricular nucleus of the thalamus. Scattered cell bodies and fibers were found in a number of other forebrain and brain stem areas with only a rare fiber seen in median eminence.

Origin and distribution of VIP (vasoactive intestinal polypeptide)-nerves in the genito-urinary tract.

VIP (Vasoactive Intestinal Polypeptide)-immunoreactive nerves were found throughout the genito-urinary tract of the cat; they were less numerous in the guinea pig and in the rat. In the cat, VIP nerves were particularly numerous in the neck of the urinary bladder and proximal urethra, in the uterine cervix and in the prostate gland. The nerves were found in smooth muscle, around blood vessels and in the connective tissue immediately beneath the epithelium. Ganglia were found below the trigonum area of the bladder, in the wall of the proximal urethra, and in paracervical tissue. VIP-immunoreactive nerve cell bodies occurred in all these ganglionic formations. These ganglia probably represent the origin of the VIP nerves of the genital tract since their removal in the female cat greatly reduced the VIP nerve supply. Transection of the hypogastric nerves had no overt effect. Transection of the cervix eliminated the VIP nerves above the level of the lesion, except those in the ovaries, supporting the view that the VIP nerves of the uterus and the oviduct are derived from a paracervical source.

The differential distribution of vasoactive intestinal polypeptide in the normal human female genital tract

VIP-like immunoreactive material is present in the female reproductive tract, with a distinct pattern of distribution. The highest concentrations of extractable material and immunoreactive nerve fibres were found in the cervix and vagina. In the cervix these fibres were seen below the surface epithelium and around cervical glands as well as in association with blood vessels and smooth muscle bundles. In the vagina the nerve fibres were most abundant in th superficial regions of the lamina propria. Scattered fibres were also present in the rest of the uterus and in the fallopian tubes. Chromatographic evidence indicates that this VIP-like material is of a similar molecular size to that extracted from other organs. Possible roles for VIP in the regulation of myometrial activity and of cervical and vaginal dilation and secretion are proposed.

Distribution of vasoactive intestinal polypeptide in the rat and mouse brain

The distribution of cell bodies and nerve fibers that combine with antisera to vasoactive intestinal polypeptide (VIP) was studied by immunohistochemistry in combination with radioimmunoassay in the brain of rat and mouse. The highest concentrations (60pmol/g wet wt) of immuno-reactive VIP were found in the cerebral cortex and in certain limbic structures, whereas the concentrations in the basal ganglia, thalamus, lower brain stem, cerebellum and spinal cord were low (<15pmol/g). VIP-immunoreactive cell bodies were found mainly in the cerebral cortex and the limbic system, with the great majority of them in neo- and allocortical areas. In the neocortex the VIP-containing cell bodies were found in layers II-V in all areas. The cells were fusiform or stellate shaped, resembling intracortical and corticocortical association neurones. In the pyriform and entorhinal cortex the cell bodies were located mainly in layer II. In the hippocampal complex VIP-containing cell bodies occurred in both the subiculum, areas CA1 and CA3 and the dentate gyrus. Most of the cells had the appearance of interneurones, some of them probably being identical with basket cells. Of subcortical areas, the amygdala had the largest number of VIP-containing cell bodies; they were numerous in all amygdaloid nuclei except in the central nucleus. Non-cortical areas where there were cell bodies containing VIP included the anterior olfactory nuclei, the bed nucleus of stria terminalis, lateral septum, suprachiasmatic nucleus, superior colliculus, and the mesencephalic periaqueductal gray. VIP-immunoreactive fibres had a distribution which on the whole paralleled that of the cell bodies, suggesting that many of the VIP-containing cells project locally. VIP-containing fibres were numerous in the following areas: the entire neocortex, the pyrifom cortex, the entorhinal cortex, the hippocampal complex, the amygdala (the central nucleus in particular), the anterior olfactory nuclei, the nucleus accumbens, ventral pallidum, bed nucleus of stria terminalis, suprachiasmatic nucleus, medial preoptic nucleus, median eminence, lateral geniculate body, pretectum, superior colliculus, periaqueductal gray, and the lateral parabrachial nucleus. Only few, scattered fibres were seen in other parts of the brain stem, in the striatum, thalamus and spinal cord. The cerebellum was devoid of VIP-containing fibres. VIP-containing neurones seem to form predominantly local projections. In addition, some VIP-containing neurones probably also form long projections, such as descending and transcallosal projections from the cortical cells, and projections from the amygdala to preoptic, hypothalamic and basal forebrain areas. The characteristic telencephalic distribution of the neurones that contain VIP suggests a role for this peptide in cortical and limbic functions.

Radioimmunologic localization of vasoactive intestinal polypeptide in hypothalamic and extrahypothalamic sites in the rat brain

Using a specific radioimmunoassay (RIA), we have quantitated the hypothalamic and extrahypothalamic distribution of vasoactive intestinal polypeptide (VIP) in th rat brain. Highest concentrations of VIP were found in cerebral cortex, suprachiasmatic nucleus, and medial amygdaloid nucleus. Lower concentrations were found in the anterior hypothalamic area, medial preoptic area, peri- and paraventricular nuclei, and hippocampus. Significant levels of VIP were also found in the anterior pituitary. Very little VIP was detected in median eminence and cerebellar cortex. This distribution of VIP in areas of the rat brain known to be important to neuroendocrine function suggests a role for VIP in the control of anterior pituitary events.

On the immunocytochemical localization of the vasoactive intestinal polypeptide.

The distribution of vasoactive intestinal polypeptide (VIP) immunoreactive nerves and endocrine cells in the gastrointestinal tract and pancreas of a number of mammalian and submammalian species has been examined in order to throw light on the exact localization of this peptide. Seven out of 8 VIP antisera demonstrated numerous nerve fibers in the gut, whereas one antiserum (TR2) revealed only scattered, few nerve fibers. The distribution of endocrine cells demonstrated by the different VIP antisera varied considerably. Thus, some antisera demonstrated only endocrine cells in the feline antrum, others only colonic endocrine cells and still others only endocrine cells of the upper gut and pancreas. The variability in staining pattern of endocrine cells as well as recent radioimmunological data makes it opportune to suggest that true VIP is a neuronal peptide and that endocrine cells store peptides resembling, but not being identical with, VIP (VIPoids).