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Biomedical subjects

P Panula

Publications and source records attributed to P Panula.

At least 127 records · Page 7Linked to original sources

Distribution of histaminergic neurons in the brain of the lamprey Lampetra fluviatilis as revealed by histamine-immunohistochemistry.

An antiserum against conjugated histamine was used to study the distribution of histaminergic neurons in the CNS of the lamprey Lampetra fluviatilis. Numerous histamine-immunoreactive cell bodies were detected in the dorsal and ventral hypothalamic nuclei and in the adjacent postinfundibular commissural nucleus. Histamine-immunoreactive fibers of high density were present in the ventral hypothalamus, and fibers could also be traced dorsally from the hypothalamus to the corpus striatum and septal nucleus where they appeared to terminate in dense plexuses. Another, smaller group of histamine-immunoreactive perikarya was observed in the border area between mesencephalon and rhombencephalon, near the caudal pole of the mesencephalic reticular nucleus. Sparsely distributed histamine-immunoreactive fibers were present in the ventral mesencephalon. The distribution of histaminergic neurons in cyclostomes, which diverged very early from the main vertebrate line, shows similarities with the corresponding systems in the CNS of amphibians and mammals, which suggests that histaminergic neuronal systems are phylogenetically old and have been conserved during evolution.

Animals↗

An analysis of histaminergic efferents of the tuberomammillary nucleus to the medial preoptic area and inferior colliculus of the rat.

The efferent projections of the five histaminergic neuronal subgroups in the tuberomammillary nucleus to the medial preoptic area (MPO) and inferior colliculus (IC) were examined by immunocytochemistry with antihistidine decarboxylase (HDC) antibodies combined with retrograde axonal tracing with Fast Blue (FB). The term "E groups" were used for the histaminergic neuronal subgroups. About 10% of the HDC-immunoreactive (HDCI) neurons were retrogradely labeled after FB injection into the MPO. The labeled neurons were not concentrated in any particular area, but were diffusely distributed bilaterally in all the subgroups. About two-thirds of the labeled neurons were observed on the side ipsilateral to the injection site and one-third on the contralateral side. The percentages of labeled neurons (double-labeled neurons/HDCI neurons) in the five subgroups were not significantly different with each other. The percentages in group E1 and E2 were particularly close, while that in group E4 resembled that in group E5. About 4% of the HDCI neurons were retrogradely labeled after the dye injections into the IC, and about half of the labeled neurons were detected on the ipsilateral side. The percentage of the double-labeled neurons in the five groups were not significantly different. Furthermore, those in E1 and E2, and in E4 and E5 were almost identical, respectively, to the situation following injection of FB into the MPO. These results indicate that each subgroup of histaminergic neurons in the tuberomammillary nucleus has similar efferent projections to the MPO and IC.

Animals↗

Immunohistochemical localization of 5-hydroxytryptamine, histamine and histidine decarboxylase in the rat major pelvic and coeliac-superior mesenteric ganglion.

The localization of 5-hydroxytryptamine (5-HT), histamine and histidine decarboxylase (HDC), the enzyme synthesizing histamine, was studied in the rat major pelvic and coeliac-superior mesenteric ganglia by an indirect immunofluorescence technique. Small cells (10-20 microns in diameter) exhibiting 5-HT, histamine or HDC immunoreactivities were observed in clusters or occurred as solitary cells in both ganglia. In the major pelvic ganglia, solitary histamine-immunoreactive principal neurons were also observed. Colocalization studies indicated that all 5-HT-, histamine- and HDC-immunoreactive small cells in these ganglia were labelled with tyrosine hydroxylase (TH), suggesting that they are small intensely fluorescent (SIF) cells. In the coeliac-superior mesenteric ganglia, all TH-immunoreactive SIF cells were also intensely immunoreactive for 5-HT and HDC. In the major pelvic ganglia, all TH-immunoreactive SIF cells contained 5-HT immunoreactivity, and the majority of them were also intensely immunoreactive for HDC. In both ganglia, however, only a subpopulation of TH-immunoreactive SIF cells displayed histamine immunoreactivity. The results indicate that in the rat major pelvic and coeliac-superior mesenteric ganglia, a population of catecholamine-containing SIF cells contain 5-HT and histamine suggesting a diverse role SIF cells may have in so far as modulation of ganglion transmission is concerned.

Animals↗

Peptide YY-like immunoreactivity in sympathetic neurons of the rat.

The occurrence of peptide YY-like peptides in parts of the sympathetic nervous system of the rat was studied by immunocytochemistry and immunochemistry plus analysis by high performance liquid chromatography. Peptide YY-immunoreactive neurons and nerve fibers were detected in the superior cervical ganglion. Co-localization studies indicated that peptide YY and neuropeptide Y immunoreactivities co-exist in a subpopulation of neurons of the superior cervical ganglion. Immunochemical analysis revealed peptide YY-immunoreactive material, distinct from neuropeptide Y, in extracts of the superior cervical ganglion. On reverse-phase high performance liquid chromatography, extracts of superior cervical ganglion revealed several peaks of peptide YY-like immunoreactive material, one of which eluted close to the position of authentic porcine peptide YY. Peptide YY-immunoreactive nerve fibers were also present in sympathetic target tissues including the auricula and atria of the heart, carotid body, submandibular salivary gland and the adrenal cortex. It is suggested that peptide YY and/or peptide YY-like peptides are present not only in endocrine cells, but also in a subpopulation of cell bodies and fibers of the peripheral sympathetic nervous system.

Animals↗

A histamine-containing neuronal system in human brain.

A well-organized network of varicose fibers was revealed throughout the frontal and temporal cortex of adult humans with specific antisera against histamine. The densest network of fibers was seen in lamina I, where varicose fibers were seen to run in parallel to the overlying pia mater. Electron microscopic immunohistochemistry revealed histamine-immunostaining in granules in a small number of nerve fibers and varicosities. Hypothalamic samples obtained from autopsy brains of adult humans revealed numerous histamine-immunoreactive nerve cell bodies in the posterior basal hypothalamus in and around the tuberomammillary nucleus. The results suggest that a histaminergic neuronal system reminiscent of that described in rodents is present in human brain.

Cerebral Cortex↗

Mast cells in the labial salivary glands of patients with Sjögren's syndrome: a histochemical, immunohistochemical, and electron microscopical study.

Mast cells in labial salivary glands obtained from patients with xerostomia with or without focal sialadenitis/Sjögren's syndrome were studied. There was no significant correlation between the intensity of local lymphocyte infiltration and the morphometrically analysed number of mast cells staining positive with toluidine blue. Histamine staining with heterologous 11C antiserum showed significantly fewer positive cells than staining with toluidine blue (mean (SD) 62 (10) v 138 (30)). This suggests heterogeneity of the mast cell population. Furthermore, there was a correlation between the focus score and the number of mast cells containing histamine. This suggests that the proliferation of mast cells containing histamine may be locally regulated by the immune inflammation, possibly through mediators from macrophages and fibroblasts. In contrast, the number of mast cells staining positive with toluidine blue could not be used as a marker of the degree of local inflammation. Although transmission electron microscopic analysis did not disclose signs of 'en masse' mast cell degranulation, mast cells may have a role in the local disease process.

Cell Count↗

Identification of histaminergic neurons in Aplysia.

1. We have identified putative histaminergic neurons in the central nervous system of Aplysia californica by light-microscopic autoradiography after uptake of [3H]histamine and by immunohistochemistry with the use of an antibody specific for histamine. 2. In the cerebral ganglion cells previously shown to contain histamine (C2 and 2 large neighboring cells in the E cluster and a group of smaller cells in the L cluster) were identified both by uptake of [3H]histamine and by histamine immunoreactivity. The identification of C2 was confirmed by experiments in which individual C2s were characterized electrophysiologically and injected with Lucifer yellow before processing for immunohistochemistry. The giant serotonergic neuron did not take up [3H]histamine and was not immunoreactive. 3. In the abdominal ganglion two clusters of cells--one in the left hemiganglion and the other in the right--took up [3H]histamine and were histamine immunoreactive. These clusters are located in the regions occupied by the 30 identified respiratory interneurons, R25 and L25. Individual cells in the R25 and L25 clusters were identified electrophysiologically, marked by injection of Lucifer yellow, and processed for immunocytochemistry. Eleven of the 30 L25 cells examined (from 7 ganglia) and 2 of the 25 R25 cells (from 6 ganglia) that had been marked with Lucifer yellow were also histamine immunoreactive. 4. Also in the abdominal ganglion, identified cells in the L32 cluster were not histamine immunoreactive and did not take up [3H]histamine. These interneurons, which mediate presynaptic inhibition, had previously been considered histaminergic. Neurons in the ganglion known to use transmitters other than histamine (L10, R2, RB cells, and bag cells) were not histamine immunoreactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗

Cells of origin of histaminergic afferents to the cat median eminence.

The exact origin of histaminergic neuronal perikarya sending axons to the median eminence and posterior pituitary was investigated in the cat by using two colour double-immunostaining methods: unconjugated wheat germ agglutinin or cholera toxin as retrograde tracers combined with histamine (HA) immunohistochemistry. HA immunohistochemistry revealed the presence of HA-immunoreactive terminal-like fibers both in the external layer of the median eminence and neural lobe of the pituitary. The double-labeling studies further demonstrated the histaminergic innervation of the median eminence and neural lobe by a few HA-immunoreactive neuronal perikarya located in the posterior hypothalamus.

Animals↗

Changes of the membrane potential in striatal synaptoneurosome, synaptosome and membrane sac preparations induced by glutamate, kainate and aspartate as measured with a cyanine dye DiS-C2-(5).

The effects of glutamate, kainate and aspartate on the membrane potential of striatal synaptoneurosome, synaptosome and membrane sac preparations were studied by using a potential sensitive cyanine dye DiS-C2-(5). Excitatory amino acids glutamate and aspartate had a depolarizing effect on synaptoneurosomes. 7.9 microM glutamate and 2.8 microM aspartate produced a half-maximal response. Depolarizations induced by glutamate and aspartate were dependent on the concentration of extracellular sodium ions, a maximal response occurred at around 40 mM of external Na+. Kainate induced a dual effect on synaptoneurosomes. In a standard Na+-based medium a hyperpolarization, likely due to inhibition of a presynaptic sodium-dependent glutamate uptake, predominated over a postsynaptic kainate receptor-mediated depolarization that was observed when electrogenic glutamate uptake was inhibited. This interpretation was supported by results obtained with synaptosome and membrane sac preparations. In a standard Na+-based medium kainate had a hyperpolarizing effect on synaptosomes while in the membrane sac preparation kainate induced a depolarization.

Animals↗

Histaminergic system in the tree shrew brain.

This study mapped the histamine-immunoreactive neuronal system in the brain of the tree shrew (Tupaia belangeri) and compared its structure with that of the rat and guinea pig. The histamine-containing cell bodies lay in the posterior ventral hypothalamus in the tuberomammillary complex, as in the rodents. The morphology of this complex resembled that of the rat. The histaminergic axons projected to nearly all parts of the brain. The main ascending bundle ran ventromedially: the densest innervation was found in the ventral hypothalamus, preoptic area, septum, medial part of nucleus accumbens, and bed nucleus of the stria terminalis. High fiber densities were present in the amygdaloid nuclei and claustrum. Another pathway ran dorsomedially along the periventricular hypothalamus and sent fibers to all parts of the diencephalon. Part of these fibers followed the central gray to the midbrain and spread laterally below the inferior colliculus. Another descending pathway ran through the interfascicular and medial raphe nuclei to meet the pontine central gray. The densest fiber networks were seen in the dorsal tegmental and parabrachial nuclei, and around the locus coeruleus. Also the substantia nigra, interpeduncular and mesencephalic reticular nuclei, colliculi, and vestibular and raphe nuclei received a dense histaminergic innervation. The organization of the fibers in the tree shrew brain resembled more that in the guinea pig than that in the rat. As compared with the guinea pig, more fibers were present, particularly in the globus pallidus, central thalamus, and deep cerebellar nuclei. No fibers were seen in the outer layer of the piriform cortex. In Tupaia, a laminar organization of the fibers was evident in the hippocampus, in contrast to the rodents. Also, a dense periventricular fiber plexus was prominent.

Animals↗

Immunohistochemical distribution and partial characterization of FLFQPQRFamidelike peptides in the central nervous system of rats.

Two peptides that are structurally related to the molluscan tetrapeptide Phe-Met-Arg-Phe-NH2 (FMRF-NH2) were recently isolated from bovine brain extract (Yang et al.: Proc. Natl. Acad. Sci. USA 82:7757-7761, '85). These peptides have an attenuating effect on morphine-induced analgesia when injected intracerebroventricularly in rats. Antisera against the two peptides--an octapeptide, Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F8F-NH2), and an octadecapeptide, Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe- NH2 (A18F-NH2)--were raised in rabbits and characterized with standard radioimmunoassay and immunohistochemical blocking controls. This study was aimed at localizing neurons in the rat brain that contain immunoreactivity for these peptides. Cryostat sections of normal and colchicine-treated Sprague-Dawley rat brains were incubated with the specific antisera and the immunoreactivity was visualized by the PAP or the FITC method. Immunoreactive neurons were detected in the hypothalamus and nucleus of the solitary tract. Relatively dense networks of fibers and terminals were observed in the lateral parabrachial nucleus and in the nucleus of the solitary tract. Fibers and terminals were also seen in the lateral septum, amygdala, hypothalamus, neurohypophysis, thalamus, periaqueductal gray, and several medullary nuclei. In these areas the immunoreactivity was abolished when the antisera were incubated with the corresponding synthetic peptides F8F-NH2 and A18F-NH2. Preincubation of the antisera with neuropeptide Y (NPY) did not affect the staining. The results suggest that there are neurons in the rat brain that contain F8F-NH2- and A18F-NH2-like peptides. The neuronal system described here may have a role in the regulation of autonomic functions, such as hypothalamic control and respiratory functions. The neuronal connections of the cells containing F8F-NH2- and A18F-NH2-like peptides remain to be studied.

Amino Acid Sequence↗

Rat brain regional distribution and spinal cord neuronal pathway of FLFQPQRF-NH2, a mammalian FMRF-NH2-like peptide.

Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-NH2) is a peptide, originally detected by FMRF-NH2 antisera, and subsequently isolated from bovine brain. Using a specific radioimmunoassay for F-8-F-NH2, we have examined the regional distribution and characteristics of F-8-F-NH2 immunoreactivity (IR) in rat brain, spinal cord and pituitary gland. In CNS, F-8-F-NH2-IR is highly concentrated in the spinal cord, hypothalamus and pons-medulla (368, 202 and 136 fmol per mg protein, respectively); lowest values are in the cortex and hippocampus. A modest rostrocaudal gradient of F-8-F-NH2-IR was observed; levels in the sacral cord are 50% higher than in the cervical cord. Dorsal cord content is 8 times higher than in the ventral cord. Dorsal rhizotomy failed to change F-8-F-NH2-IR in the affected regions of the spinal cord while significantly reducing substance P levels. F-8-F-NH2-IR was significantly decreased caudal to a spinal transection, indicating the presence of a descending pathway within the spinal cord. The highest concentration of F-8-F-NH2-IR (1008 fmol per mg protein) was found in the neurointermediate lobe of the pituitary, while no F-8-F-NH2-IR could be detected in the anterior lobe. Immunohistochemically, F-8-F-NH2-IR was confined to nerve terminal-like structures in the neural lobe. The anterior and intermediate lobes were devoid of immunoreactive structures. HPLC characterization of F-8-F-NH2-IR in the dorsal spinal cord, medulla-pons and pituitary revealed one major immunoreactive peak which is more hydrophobic than bovine F-8-F-NH2. In addition to this material, the hypothalamus was found to contain another, more abundant F-8-F-NH2-immunoreactive peak. Analysis of F-8-F-NH2-IR from posterior pituitary with various antisera having differing affinities for F-8-F-NH2 and gamma 1-MSH indicates that the F-8-F-NH2-IR of rat pituitary is not due to gamma 1-MSH. The high concentration of F-8-F-NH2-like peptide in the dorsal spinal cord supports a role in mediating nociceptive transmission while the localization of F-8-F-NH2-IR in the posterior pituitary suggests an additional autonomic or endocrine function.

Animals↗

Histamine-immunoreactive nerve fibers in the mammalian spinal cord.

New sensitive antisera against histamine were used to study the distribution of histamine-immunoreactive nerve fibers in the spinal cord of several mammalian species. Tissues were fixed with carbodiimide by transcardiac perfusion or immersion. A few immunoreactive nerve fibers were found in the cervical spinal cord of the rat in the superficial laminae of the dorsal horn, around the central canal and scattered in the anterior horn. The density of immunoreactive fibers in the cervical spinal cord of the guinea pig and tree shrew was higher, but still low. The densest networks of histamine-immunoreactive fibers were seen in the cervical spinal cord of the pig. The laminar distribution of histamine-immunoreactive fibers was similar in all species. Histamine-immunoreactive fibers were densest in lamina X, followed by laminae I-II. Scattered fibers were also seen in the white matter in the lateral and posterior funiculus in the pig. In the rat and the guinea pig, no histamine-immunoreactive cell bodies were seen in the spinal sensory ganglia. The results suggest that the histamine-immunoreactive nerve fibers in the spinal cord may originate from the brain, probably from the posterior hypothalamus, and the fiber projection is more extensive in higher mammalian species. The role of histamine in the spinal cord is not known, but it may be involved in, e.g., pain sensation.

Animals↗

Nerve fibers showing immunoreactivities for proenkephalin A-derived peptides in the lacrimal glands of the guinea pig.

The extra- and intraorbital lacrimal glands of guinea pigs were studied for the presence and distribution of enkephalin-like immunoreactive nerve fibers. Four specific antisera against the four different enkephalin sequences contained in pre-proenkephalin A (Met-Enk, Met-Enk-Arg-Phe, Met-Enk-Arg-Gly-Leu, and Leu-Enk) were used. All of these immunoreactivities were identically distributed in varicose nerve fibers in both the extra- and intraorbital lacrimal glands. These fibers densely surrounded the glandular acini and also innervated the secretory ducts. Sympathetic denervation had no effect on these nerve fibers. The results suggest that enkephalins derived from proenkephalin A may play a role in the nervous control of the lacrimal secretion.

Animals↗

Histamine-immunoreactive nerve fibers in the rat brain.

A new immunohistochemical method that utilizes carbodiimide as a tissue fixative was applied to study the distribution of histamine-immunoreactive neuronal fibers and terminals in the rat brain. Immunoreactive fibers were observed in almost all major regions of the brain. They were most numerous in the different hypothalamic nuclei. Dense networks of immunoreactive fibers were also seen in the medial septum, nucleus of the diagonal band and ventral tegmental area. A moderate density of fibers was seen throughout the cerebral cortex, in some parts of the olfactory bulb and tubercle, bed nucleus of the stria terminalis, amygdala, basal parts of the hippocampus, inferior and superior colliculi, substantia nigra, lateral and medial parabrachial nucleus, and the nucleus of the solitary tract. Few histamine-immunoreactive fibers were seen in most parts of the caudate putamen, most thalamic nuclei, most pontine and ventral medullary nuclei. Histamine-immunoreactive neuronal cell bodies were found exclusively in the tuberomammillary nucleus, in agreement with previous reports. The results provide evidence for a widespread distribution of histamine-containing nerve fibers and terminals in the rat brain. Although immunohistochemical localization of histamine does not give direct evidence of a functional role of histamine in any brain area, this distribution suggests involvement in functions of the limbic system including the septal nuclei, hypothalamus and amygdala. The relatively dense histamine-immunoreactive fiber networks in the colliculi and dorsal cochlear nucleus indicate that this amine may play a role in visual functions and hearing. The paucity of immunoreactive fibers in the pontine and medullary areas suggests that the caudal projections originating from the tuberomammillary complex are minor ones compared to the major rostral projections. Several fiber projections originating from the tuberomammillary complex could be deduced from serial frontal, sagittal and horizontal sections. They contained fibers that crossed the midline at several levels of the brain. The results provide information on the target areas of the histaminergic neurons and form a basis for the examination of cellular contracts between the histaminergic neurons and other cells.

Animals↗

EGF- and TGF-alpha-like peptides in human fetal gut.

The presence of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF alpha) immunoreactivities in fetal human tissues was studied immunohistochemically at different gestational ages. EGF and TGF alpha immunoreactivities were detected from the 20th gestational wk. EGF immunoreactivity was limited to the small intestine, but TGF alpha immunoreactive cells were present in the colon also. According to radioreceptor assay, the intestine of a 19-wk-old human fetus contained 10 times more EGF receptor-binding substance than EGF, as measured by immunofluorometric assay. Chromatographic analysis suggests that TGF alpha-like peptides account for at least part of this activity, as so argues in favor of the presence of TGF alpha- and EGF-like peptides in the human fetal gut. Whether they are synthesized in the fetus is yet unknown.

Digestive System↗