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O Johansson

Publications and source records attributed to O Johansson.

At least 145 records · Page 8Linked to original sources
PubMed1986

A detailed account of NPY-immunoreactive nerves and cells of the human skin. Comparison with VIP-, substance P- and PHI-containing structures.

Neuropeptide Y (NPY)-like immunoreactivity has been found in autonomic nerve terminals and fibres of the normal human dermis by the use of indirect immunohistochemistry. Also a granular immunoreactivity was observed in the basal cells of the epidermis as well as in the cells of the outer root sheath of hair follicles. Thus, NPY should be considered when examining the role of different autonomic neurotransmitter candidates. Furthermore, NPY and norepinephrine may, at this level, serve together as co-transmitters or co-modulators of autonomic function. Finally, the immunoreactivity found in cells of the epidermis and the outer root sheath of hair follicles points to other functional effects so far not understood.

Adult↗
PubMed1986

Evidence for PHI-immunoreactive nerve fibres in the human skin: coexistence with VIP?

Using indirect immunofluorescence methodology, PHI-like immunoreactivity was found in a certain subpopulation of nerve fibres and terminals of the human skin. The immunoreactive fibres were mainly seen close to and around blood vessels and sweat glands, and they were of a fine-calibre type with smooth preterminal axons and a sparse plexus of varicosities at their terminal field. Furthermore, they were also observed around hair follicles, though more rarely around sebaceous glands. Finally, single PHI immunoreactive fibres could be seen in the close vicinity of the erector pili muscles. These fibres in all probability represent peripheral branches of the autonomic nervous system. Single (somatic?) immunoreactive fibers were, however, also found in the apical parts of the dermis, close to the epidermal-dermal junctional zone. The occurrence of VIP was also analysed and found to be similar to that of PHI. Thus, the present data point to a probable coexistence of PHI and VIP, a possibility that should be taken into account when discussing functional effects of VIP in human skin.

Adult↗
PubMed1985

Ultrastructural morphometric analysis of somatostatin-like immunoreactive neurones in the rat central nervous system after labelling with colloidal gold.

Nerve terminals of the rat median eminence, arcuate nucleus and spinal cord were examined in the electron microscope after post-embedding, colloidal gold labelling of immunoreactivity to somatostatin. Strong immunostaining was thus obtained together with adequate morphological preservation. Reactive boutons showed clusters of gold particles essentially confined to dense-cored vesicles. In the median eminence, the positive varicosities made up more than half of all terminals and averaged 735 nm in diameter. Those in the arcuate nucleus and spinal cord were much less numerous and generally smaller (575 nm). The labelled vesicles had mean external diameters of 109, 95 and 79 nm in the median eminence, arcuate nucleus and spinal cord, respectively. Calculations of the likely amounts of somatostatin within the vesicles of the median eminence and arcuate nucleus yielded values of 0.7 and 1.4 mM, corresponding to 190 and 230 molecules of the peptide, respectively. These data support a neurotransmitter or modulator role for somatostatin in the central nervous system.

Animals↗
PubMed1985

Immunocytochemical studies of somatostatin neurons in brain.

Immunohistochemical studies with antisera to somatostatin have, in many instances, led the way to our present understanding of the peptidergic nervous system. Somatostatin was among the first of the hypophysiotropic hormones shown to be contained in diverse neuronal circuits outside of the hypothalamus. For example, somatostatin is found within neurons ranging in location from the cerebral cortex to primary sensory neurons to enteric neurons within the gut wall. Somatostatin was also the first neuropeptide demonstrated to coexist within vertebrate neurons that also produce a classical neurotransmitter. Since this initial demonstration in sympathetic ganglionic neurons, somatostatin and numerous other neuropeptides have been demonstrated to coexist with a variety of classical neurotransmitters. The "rules" for coexistence are not clear, since somatostatin coexist in some instances with norepinephrine, in other cases with GABA, and probably with other classical transmitters as well. In some neurons, somatostatin also coexists with certain other neuropeptides. Finally, the specificity of immunohistochemical localizations of somatostatin has now been confirmed by virtue of the co-staining of somatostatin neurons with antisera to other portions of the biosynthetic precursor to somatostatin.

Animals↗
PubMed1985

Different effects of different nutrients on theophylline absorption in man.

The influence of concomitant intake of a standardized breakfast (1,840 kJ) and of carbohydrate (830 kJ), fat (645 kJ), and protein (365 kJ) on the absorption of theophylline (400 mg) from a modern formulation of choline theophylline (4 X 135 mg) was examined in 18 healthy volunteers. After fasting overnight, they ingested the drug both immediately after the meal/nutrient and on an empty stomach, fasting being continued for another 4 h. Theophylline concentrations in serum were analyzed by high-pressure liquid chromatography. The results indicate that carbohydrate and the complete breakfast, but not fat or protein, delayed the absorption of theophylline. This is of particular interest as previous animal studies suggest that theophylline may be partially absorbed by an active transport mechanism operating in glucose uptake, and as carbohydrate has been found to increase the absorption rate of phenytoin, another acidic drug with a pKa similar to that of theophylline. This emphasizes the complexity of factors regulating the absorption of drugs and their interactions with food and dietary components.

Adult↗
PubMed1984

Chemical anatomy of the brain.

The development of sensitive histochemical-neuroanatomical techniques has made it possible to analyze the content of specific compounds in single nerve cells and their processes. In consequence, it has been possible to construct detailed maps of the distribution of various types of neurons on the basis of their transmitter substance. There are now many examples of neurons containing both a classical transmitter and a peptide. In some instances the peptides seem to support the action of the classical transmitters. This interaction may have applications in the prevention and treatment of nervous disease states.

Animals↗
PubMed1984

Distribution of neuropeptide immunoreactive nerve terminals within the subnuclei of the nucleus of the tractus solitarius of the rat.

The location of substance P, enkephalin and somatostatin (SRIF), and neurophysin II immunoreactive nerve terminals and preterminal processes in the caudal part of the nucleus of the tractus solitarius (nTS) was examined by the indirect immunofluorescence method for immunocytochemistry combined with cytoarchitectural identification of nuclear subgroups in the same tissue. In 22 Sprague-Dawley rats we examined 14-micrometers-thick serial sections of the dorsal medulla at levels from 1 mm caudal to 2 mm rostral to the obex. These sections were incubated with substance P, enkephalin, somatostatin, and neurophysin II antisera. All four peptides were examined in each case and five typical levels (two caudal and three rostral to the obex) were selected for comparison of terminal distribution between peptides. All sections were photographed under the fluorescence microscope and then counter-stained with cresyl violet. This method of analysis revealed distinct patterns of neuropeptide immunoreactivity in the subnuclei of the nTS that varied according to the level of the section. The nTS is responsible for integrating respiratory, cardiovascular (baroreceptor and cardiac), and gastrointestinal functions. The ventrolateral subnucleus (Vl)nTS, ventral subnucleus (v)nTS, interstitial subnucleus (ni)nTS, and intermediate subnucleus (nI)nTS are the major respiratory subnuclei with vlnTS and vnTS prominently associated with pulmonary afferents, ni associated with laryngeal afferents, and nI with tracheal afferents. The vlnTS, vnTS, and ni showed a moderate density of somatostatin-positive nerve terminals, scattered substance P and enkephalin immunoreactivity, and no neurophysin II-positive terminals. The nI showed moderate density of substance P immunoreactive nerve terminals. The subnuclei of the nTS receiving baroreceptor and chemoreceptor afferents--dorsolateral and dorsal (dl and d) subnuclei of nTS--showed scattered substance P immunoreactive nerve terminals. The commissural nucleus of nTS (ncom), which receives most of the cardiac afferents, showed a moderate density of enkephalin-positive immunoreactive nerve terminals. The medial subnucleus (m)nTS at levels rostral to the obex, the primary site for the termination of gastrointestinal afferents, showed substance P immunoreactivity in moderate amounts and weak immunoreactivity for all the other neuropeptides. An important result of these experiments was the observation that regions of the medulla adjacent to the nTS, i.e., the ventral parasolitarius region (vPSR), dorsal (d)PSR, and the periventricular region (PVR) showed the densest amounts of immunoreactive nerve terminals.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1984

Immunohistochemical localization of somatostatin-like immunoreactivity in skin lesions from patients with urticaria pigmentosa.

Using the indirect immunofluorescence technique of Coons and collaborates, somatostatin-like immunoreactivity was found in skin lesions of patients presented with urticaria pigmentosa. The cytoplasmic immunoreactivity was sometimes of a granular type. In addition, immunofluorescence was also observed in certain surrounding connective tissue elements. No specific staining was seen when supplementing the first antiserum with control serum, nor could any unique specific immunofluorescence by found in the pathological areas (compared with skin of normal healthy volunteers) after incubation with antibodies to substance P, vasoactive intestinal polypeptide or avian pancreatic polypeptide. No thyrotropin releasing hormone or enkephalin immunoreactivity was seen in skin from either the patients or the controls.

Adult↗
PubMed1984

Immunohistochemical distribution of somatostatin-like immunoreactivity in the central nervous system of the adult rat.

The localization and distribution of somatostatin (growth hormone release-inhibiting hormone; somatotropin release-inhibiting factor) have been studied with the indirect immunofluorescence technique of Coons and collaborators and the immunoperoxidase method of Sternberger and coworkers using specific and well-characterized antibodies to somatostatin, providing semiquantitative, detailed maps of somatostatin-immunoreactive cell profiles and fibers. Our results demonstrate a widespread occurrence of somatostatin-positive nerve cell bodies and fibers throughout the central nervous system of adult, normal or colchicine-treated, albino rats. The somatostatin cell bodies varied in size from below 10 micron up to 40 micron in diameter and could have only a few or multiple processes. Dense populations of cell somata were present in many major areas including neocortex, piriform cortex, hippocampus, amygdaloid complex, nucleus caudatus, nucleus accumbens, anterior periventricular hypothalamic area, ventromedial hypothalamic nucleus, nucleus arcuatus, medial to and within the lateral lemniscus, pontine reticular nuclei, nucleus cochlearis dorsalis and immediately dorsal to the nucleus tractus solitarii. Extensive networks of nerve fibers of varying densities were also found in most areas and nuclei of the central nervous system. Both varicose fibers as well as dot- or "dust-like" structures were seen. Areas with dense or very dense networks included nucleus accumbens, nucleus caudatus, nucleus amygdaloideus centralis, most parts of the hypothalamus, nucleus parabrachialis, nucleus tractus solitarii, nucleus ambiguus, nucleus tractus spinalis nervi trigemini and the dorsal horn of the spinal cord. One exception is the cerebellum which only contained few somatostatin-positive cell bodies and nerve fibers. It should be noted that somatostatin-positive cell bodies and fibers did not always conform to the boundaries of the classical neuroanatomical nuclei, but could often be found in areas between these well-established nuclei or occupying, in varying concentrations, only parts of such nuclei. It was difficult to identify with certainty somatostatin-immunoreactive axons in the animals studied. Some pathways could, however, be demonstrated, but further experimental studies are necessary to elucidate the exact projections of the somatostatin-immunoreactive neurons in the rat central nervous system.

Animals↗
PubMed1984

In vivo absorption of theophylline and salicylic acid from rat small intestine.

In vivo absorption of theophylline and salicylic acid from the rat small intestine was studied by a closed segment technique. The drugs were administered at 1 and 4 mM in dissolved form, both in the presence and absence of phlorizin (0.01 mM). Drug concentrations were measured by high-pressure liquid chromatography. Phlorizin inhibited the absorption of theophylline (pKa = 8.6) at 4 mM but not at 1 mM. In contrast, the absorption of salicylic acid (pKa = 3) both at 1 and 4 mM was unaffected by phlorizin. This suggests that an active transport system, sensitive to phlorizin, is involved in the rat intestinal absorption of theophylline, but not in that of salicylic acid. Apart from differences in drug structure, differences in the degree of ionization may influence the access of acidic drugs to this transport system.

Animals↗
PubMed1984

Transmitter and peptide systems in areas involved in the control of blood pressure.

The distribution of catecholamine neurons in the dorsal vagal complex is described on the basis of indirect immunofluorescence histochemistry using antisera to three enzymes in the catecholamine synthesis, tyrosine hydroxylase, dopamine-beta-hydroxylase and phenylethanolamine-N-methyltransferase, allowing differentiation between dopamine, noradrenaline and adrenaline cells. In addition attention was focused on the occurrence of two peptides, neuropeptide Y (NPY) and neurotensin in this region. It could be established that they partly were present in subpopulations of the A2/C2 catecholamine neurons. The significance of this coexistence of a peptide and a catecholamine is discussed.

Animals↗
PubMed1984

Ultrastructural immunocytochemical studies on CCK-and neurotensin-like immunoreactivity in the nucleus accumbens of the rat.

Using the peroxidase-antiperoxidase technique of Sternberger and collaborators the ultrastructural localization of cholecystokinin- and neurotensin-like immunoreactivity was studied in the nucleus accumbens of the albino rat. The immunoreactive material was localized to nerve terminals making probable axodendritic or axo-axonic contacts with neighbouring nerve cells. Within the nerve terminals most immuno-reactivity was confined to so-called large dense-core vesicles.

Animals↗