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Biomedical subjects

A Hervonen

Publications and source records attributed to A Hervonen.

At least 91 records · Page 5Linked to original sources
PubMed1984

Histochemically demonstrable catecholamines in sympathetic ganglia and carotid body of spontaneously hypertensive and normotensive rats.

The catecholamine content and morphology of the superior cervical and the hypogastric ganglion and the carotid body were studied in Spontaneously Hypertensive Rats (SHR) before (at the age of 6 weeks) and after (at the age of 20 weeks) becoming hypertensive, with Wistar Kyoto (WKY) rats as controls. The study was performed by formaldehyde-induced fluorescence method combined with quantitative microfluorimetry of catecholamines. At the age of 6 weeks the only significant difference observed between the rat strains was a greater number of small intensely fluorescent (SIF) cells in the superior cervical ganglion of SHR. At the age of 20 weeks the fluorescence intensity was higher in the principal neurons of the superior cervical ganglion and in glomus cells of the carotid body of SHR compared to WKY. The volumes of superior cervical ganglion and carotid body were larger in 20-week-old SHR compared to WKY. In the hypogastric ganglion differences were not found between SHR and WKY rats. The present results show differences in the superior cervical ganglion and in the carotid body of adult SHR compared to controls. These differences develop during the time period when the SHR become hypertensive, and might be functionally significant in the regulation or maintenance of the increased blood pressure in SHR rats.

Animals↗
PubMed1984

Effect of prolonged physical training on the histochemically demonstrable catecholamines in the sympathetic neurons, the adrenal gland and extra-adrenal catecholamine storing cells of the rat.

The effect of daily physical training for 24 months on the sympathetic neurons, adrenal gland, extra-adrenal catecholamine storing cells and on the heart was investigated in rats. The tissue catecholamine fluorescence intensity was determined by microfluorimetric quantitation of catecholamines. The maximal and final body weights were significantly lower in trained animals. The trained rats showed prominent increase of heart weight relative to body weight, while the adrenals did not enlarge. The adrenergic nerve fiber density of the heart and the fluorescence intensity of the terminal axons were significantly increased. There were no changes in the fluorescence intensity of the perikarya of the sympathetic neurons and the amount of extra-adrenal catecholamine storing cells after physical exercise. The volume of the superior cervical ganglion was doubled and the neuronal perikarya were enlarged in trained animals. The prolonged physical training throughout the life span of the rat gave new information about the reactions of the sympathetic nervous system to physical exercise.

Adrenal Medulla↗
PubMed1984

Location of substance P-, bombesin-gastrin-releasing peptide, [Met5]enkephalin- and [Met5]enkephalin-Arg6-Phe7-like immunoreactivities in adult human sympathetic ganglia.

Indirect immunofluorescent methods were used to study peptides in human paravertebral sympathetic ganglia. [Met5]enkephalin, [Met5]enkephalin-Arg6-Phe7 and bombesin-gastrin-releasing peptide-like immunoreactivities were localized in varicose nerve fibers, which often formed basket-like networks around principal ganglion cells. Substance P-like immunoreactivity appeared frequently as solitary varicose nerve fibers and occasionally as networks. No immunolabeled cell bodies were discovered with any of the antisera used, including antibodies raised against molluscan cardioexcitatory peptide Phe-Met-Arg-Phe-NH2. The results demonstrate the presence of peptides within nerve fibers and terminals but not cell bodies of human paravertebral sympathetic ganglia. The localization suggests that the peptides have neurotransmitter or neuromodulator roles in the ganglia.

Enkephalin, Methionine↗
PubMed1984

The ultrastructure of hypertrophied paraganglia in aged rats.

The catecholamine-storing cells in the paraganglia of old rats showed structural characteristics common to adrenomedullary and paraganglionic cells of young animals. No sign of degeneration was found. Lipofuscin pigment was observed in most cells. The paraganglia were innervated and well supplied by fenestrated sinusoidal capillaries. Their fine structure suggests active endocrine function. An increase in the total bulk of the paraganglia in old rats suggests that they have a physiological role in senescence.

Aging↗
PubMed1983

Microfluorimetric quantification of catecholamine fluorescence in rat sympathetic ganglia.

The formaldehyde-induced fluorescence (FIF) technique was used to generate catecholamine fluorophores in the perikarya of the sympathetic neurons in the superior cervical ganglion of adult rats. During microfluorimetric quantification, the photodecomposition was eliminated by a rapid measuring procedure with a small excitation field and by using only visible light between the measurements. The catecholamine fluorescence, induced in protein microdroplets with increasing noradrenaline concentrations, was linear up to 2 X 10(-2) M which exceeds the noradrenaline content of even the most intensively fluorescent neurons. Thus, the differences in fluorescence intensities directly reflect the physiological state of each neuron with respect to their catecholamine content. The mean histograms reveal the changes which can only occur in certain neurons, and which can disappear if the mean only is assessed. The microfluorimetric method was sensitive enough to detect even minute changes induced by reserpine treatment in the catecholamine content of the sympathetic ganglion cells.

Animals↗
PubMed1982

Catecholamine- and acetylcholinesterase-containing nerves in human lower respiratory tract.

The innervation of human lower respiratory tract was studied with special emphasis on airways with sodium-potassium glyoxylic acid (SPG) and acetylcholinesterase (AChE) methods to demonstrate catecholamine-containing and acetylcholinesterase-containing nerve fibers. AChE-method revealed a rich network of cholinesterase positive nerves both inside the bronchial glands where they run around and between the acini, and the airway smooth muscle from secondary bronchi to terminal bronchioli. No AChE-positive fibers were found in connection with the blood vessels or within the epithelium of bronchi or bonchioli. The AChE-positive nerve fibers in bronchial smooth muscle greatly outnumbered those containing catecholamine. The SPG-method revealed the presence of adrenergic nerves from the level of secondary bronchi to that of terminal bronchioli. These nerve fibers were most abundant in bronchial glands, where their amount was equal and distribution similar to those of AChE-containing nerve fibers. Outside the glands adrenergic fibers were constantly seen in connection with the bronchial blood vessels in connective tissues surrounding bronchi. A few nerve fibers were also present in airway smooth muscle from the secondary bronchi to terminal bronchioli.

Acetylcholinesterase↗
PubMed1981

Nerve endings in human sympathetic ganglia.

Forty-eight human sympathetic ganglia from 22 sympathectomies were examined ultrastructurally after one of three different fixations: (1) glutaraldehyde + osmium tetroxide, (2) glutaraldehyde + potassium dichromate + osmium tetroxide, or (3) potassium permanganate. Three different kinds of synapsing nerve ending could be identified after all fixation schedules. Type 1: "Cholinergic," containing small, agranular vesicles 40-60 nm in diameter (75% of all vesicles) and some large granular vesicles (100 nm in diameter). The number of type 1 profiles decreased with increasing age. Type 2: "Adrenergic," containing small granular vesicles 40-70 nm in diameter (over 90% of the vesicles). Type 3: "Nonadrenergic, noncholinergic," characterized by large opaque vesicles 80 -160 nm in diameter (over 50% of all vesicles). The frequencies of the types were counted after potassium permanganate fixation: type 1 - 71%, type 2 - 23%, and type 3 - 6%. In addition, at least two types of nerve profiles were observed which did not form synapses: (1) profiles entirely filled with mitochondria (mitochondrial accumulation), and (2) large nerve profiles full of different kinds of vesicles, myelin figures, and mitochondria (axonal dilatation). It is concluded that the sympathetic ganglion cells receive cholinergic and adrenergic innervation and also a third type of innervation, the possible peptidergic nature of which is discussed.

Adult↗
PubMed1981

Immunohistochemical localization of the catecholamine-synthesizing enzymes, substance P and enkephalin in the human fetal sympathetic ganglion.

The human fetal sympathetic ganglia were studied using the indirect peroxidase-antiperoxidase PAP method for immunocytochemical demonstration of three catecholamine-synthesizing enzymes, tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT) as well as the neuropeptides leucine (Leu5)-enkephalin and substance P. The neuroblasts of the ganglia showed intense peroxidase immunoreactivity for TH, moderate reaction to DBH, and no reaction to PNMT. The small intensely fluorescent (SIF) cells situated along the blood vessels also showed positive labelling for only two enzymes, TH and BDH. The immunocytochemical localization of these enzymes suggests that both neuroblasts and SIF cells synthesize noradrenalin. Neither the neuroblasts nor SIF cells showed a reaction to substance P, and only the SIF cells contained enkephalin-like immunoreactivity. The role of enkephalin in the noradrenalin-containing SIF cells is unknown, but may be related to neuromodulation of ganglionic transmission.

Catecholamines↗
PubMed1980

Immunocytochemical localization of tyrosine hydroxylase in the human fetal nervous system.

The peroxidase-antiperoxidase (PAP) technique is used to determine the cellular localization of tyrosine hydroxylase in the human fetal nervous system. Antiserum to trypsin-treated tyrosine hydroxylase from the bovine adrenal medulla can be detected immunocytochemically in peripheral sympathetic neurons in the 8-mm (5-week) fetus, but can not be detected in the central nervous system until later stages of development. The cytological features and distribution of the neuronal perikarya and processes labeled for the enzyme are similar to those of the catecholaminergic neurons previously identified by histofluorescence. These findings indicate that specific neurons in the human fetus have at least one of the enzymes necessary for the biosynthesis of catecholamines and that cross-species reactivity exists between antiserum produced to the bovine tyrosine hydroxylase and human tissues.

Brain↗
PubMed1980

Immunocytochemical localization of enkephalin and substance P in the dorsal tegmental nuclei in human fetal brain.

The peroxidase-antiperoxidase (PAP) technique is used to examine the localization of methionine [Met 5]-enkephalin and substance P in the dorsal tegmental nuclei of the human fetal brain. Specific antiserum to both peptides is immunocytochemically detectable in neuronal perikarya and varicose processes in the human dorsal tegmental nuclei at 17-21 weeks of gestation. However the two peptides show a differential distribution in the central versus peripheral portions of the nucleus. Enkephalin-like immunoreactivity is primarily localized in perikarya along the pripheral borders of the tegmental nuclei, whereas substance P is present primarily in varicose terminals and a few perikarya in the more central portions. These findings suggest that substance P-containing terminals in dorsal tegmental nuclei are probably derived from afferent axons and that enkephalin is present in intrinsic neurons.

Afferent Pathways↗
PubMed1980

Nerve endings in the human prostate.

The ultrastructure of nerve endings in the human prostate was studied using glutaraldehyde-OsO4 and KMnO4 fixation. The nerve endings were classified into three categories according to the size of the vesicles and the contents of the synaptic profiles. In addition to the conventional adrenergic and cholinergic axons, a third type of axon profile containing a predominance of large granular vesicles was constantly found. Synaptic contacts were found only on smooth muscle cells. No epithelial innervation could be demonstrated. The functions and possible transmitters of the various types of axon terminals are discussed.

Aged↗
PubMed1980

Ultrastructural localization of enkephalin-like immunoreactivity in the rat adrenal medulla.

The PAP method was applied to adrenomedullary cells to demonstate the subcellular localization of ELI. The labeled cell-groups were identified from flat-embedded virbratome sections by light microscopy. Electron microscopy showed that the precipitate was associated with the storage granules of the cells. The number of labeled granules varied greatly from cell to cell. In corresponding to those showing heavy staining by light microscopy, all the granules were stained with precipitate. It is suggested that the peptide responsible for the ELI might be released together with the catecholamines.

Adrenal Medulla↗
PubMed1980

Mitochondrial accumulations in nerve fibres of human sympathetic ganglia.

The fine structure of mitochondrial accumulations in axonal swellings of human sympathetic ganglia is described. A typical swelling contained, in addition to regularly organized mitochondria, bundles of neurofilaments and vesicles as well as large dense-cored vesicles and myelin figures. Synaptic contacts between axonal swellings with mitochondrial accumulations and ganglion cells were not found. A three-dimensional model of the mitochondrial accumulation based on serial sectioning is presented. The possible degenerative and regenerative features of these accumulations are discussed. It is possible that mitochondrial accumulations are functionally active energy producers rather than results of degenerative processes.

Axons↗
PubMed1980

Glyoxylic acid fluorescence and ultrastructural studies of neurones in the coeliac-superior mesenteric ganglion of the aged rat.

Sympathetic post-ganglionic neurones in the coeliac-superior mesenteric ganglion (CSMG) complex of aged (24 month) rats have been studied by glyoxylic acid-induced fluorescence and electron miscroscopy. Comparisons have been made with the CSMG of young adult (4 month) rats. In the aged rats the noradrenaline fluorescence of the majority of neuronal perikarya was very low or absent and few intraganglionic fluorescent varicosities were seen. Lipofuscin pigment was very prominent at the nuclear pole region of neurones and also in dendrites and axonal processes. Ultrastructural studies revealed large accumulations of residual bodies at the nuclear poles and in axons and dendritic profiles. Within the perikarya many mitochondria were distorted or swollen, the rough endoplasmic reticulum was disarranged and much dilated as were Golgi cisternae. Primary lysosomes were encountered throughout the neurone perikaryon and its axonal or dendritic processes. In contrast to the young adult CSMG, no evidence for loading of transmitter storage vesicles with an identical dose level of 5-hydroxydopamine was detected in any part of the neurones of aged rats. This might reflect an impairment of the uptake mechanisms and/or storage of noradrenaline in aged sympathetic neurones and their axonal and dendritic processes.

Aging↗
PubMed1980

Immunohistochemical demonstration of VIP, [Met5]-and [Leu5]-enkephalin immunoreactive nerve fibres in the human prostate and seminal vesicles.

The distribution of nerves containing immunoreactivity for the VIP and enkephalins has been demonstrated in the human prostate and seminal vesicles using the immunoperoxidase bridge. VIP-containing nerves were detected in both organs studied mainly in association with the epithelium, while nerves containing ELI seemed to be related to smooth muscle. Compared with the distribution of adrenergic and cholinergic nerves in the prostate marked differences in the density of the innervation were detected. The possible nature of these peptide-containing nerves is discussed.

Acetylcholinesterase↗
PubMed1980

The effect of ageing on the SIF-cells in the hypogastric (main pelvic) ganglion of the rat.

The effect of ageing on SIF-cells was studied by the formaldehyde-induced fluorescence (FIF) method and by electron microscopy (EM). Microspectrofluorimetry was used to record emission spectra in FIF preparations. In newborn and in young adult (8--12 weeks) rats a single type of SIF-cell emitting greenish-yellow FIF was found while in aged rats a second type of SIF-cell emitting yellowish-brown granular FIF was also present. The intensity of the yellowish-brown FIF was lower than that of the greenish-yellow FIF. Also a few bright cytoplasmic fluorescent areas were occasionally found in some SIF-cells. The distribution of the SIF-cells through the ganglion did not change remarkably with age. In EM after glutaraldehyde-fixation in newborn and in young adult rats two types of small granule-containing (SGC) cells were distinguished according to the size of the dense cored vesicles, 1) 50--150 nm and 2) 50--250 nm. In aged rats, a third type of SGC-cells containing 50 x 250 nm elongated dense core vesicles could also be distinguished. After KMnO4-fixation in newborn and in young adult rats the classification was identical with glutaraldehyde-fixation. In aged rats three types of storage granules were found after KMnO4, 1) 100--300 nm empty vesicles and 2) 100--300 nm vesicles with small dense core, 3) 100--500 nm irregular in shape and filled with electron opaque material with a more dense core.

Aging↗