Biomedical subjects

A Hervonen

Publications and source records attributed to A Hervonen.

At least 73 records · Page 4Linked to original sources

PubMed1987

Localization of enkephalin- and neurotensin-like immunoreactivities in cat adrenal medulla.

Enkephalin (ENK)- and neurotensin (NT)-immunoreactivities (IR) were localized in cat adrenal medulla using immunocytochemistry. ENK was localized mainly in adrenaline cells, 70%-80% of which were heavily labelled. About 5%-10% of the noradrenaline cells were ENK-immunoreactive (IR). A dense network of ENK-IR nerves was localized among adrenaline cells. NT was localized only in the noradrenaline cells, 60%-70% of which were immunoreactive. NT- and ENK-IR were localized in separate noradrenaline cells. A dense network of NT-IR nerves was restricted among noradrenaline cells. The present findings confirm that ENK- and NT-like peptides are localized in separate adrenal medullary cells and demonstrate that also the preganglionic nerves are divided in subpopulations according to their neuropeptide content. These nerves have a selective localization among adrenaline and noradrenaline cells and may have physiological significance in the control of secretion of catecholamines and neuropeptides from adrenal medulla.

Adrenal Medulla↗

PubMed1987

Histochemical demonstration of adrenergic nerves in the stroma of human cornea.

Both fetal and adult human corneas were subjected to a variety of histochemical techniques for the demonstration of catecholamines. The techniques included both sodium-potassium-glyoxylic acid-induced fluorescence (SPG) and formaldehyde-induced fluorescence after freeze-drying (FIF) procedure. In fetal corneas the presence of adrenergic nerve fibers could be demonstrated by both SPG and FIF techniques. In contrast, in adult human corneas the adrenergic nerves could be identified only with the SPG technique, whereas with FIF the identification of specific catecholamine fluoresence was not possible due to extensive collagen autofluorescence.

Adrenergic Fibers↗

PubMed1986

Microspectrofluorometric quantitation of autofluorescent lipopigment in the human sympathetic ganglia.

The age-related changes in lipopigment autofluorescence were studied by microspectrofluorometry in three different types of human neurons: the sympathetic neurons of the stellate and superior mesenteric ganglion and pyramidal neurons of the frontal cortex. The age-related increase in lipopigment autofluorescence was more rapid in stellate ganglion but similar linear increases were found also in superior mesenteric ganglion and frontal cortex. There was an age-related shift in the autofluorescence from yellow to orange in the ganglia. This may be due to the accumulation of neuromelanin in noradrenergic neurons. Lipopigments were identified in sympathetic neurons at the age of 4 months and all neurons carried pigment granules after the age of 64 years. It is concluded that lipopigment autofluorescence is a useful marker for cellular ageing in both the peripheral and the central nervous system.

Ganglia, Sympathetic↗

PubMed1986

The effect of bleaching on the lipopigments in the human sympathetic neurons.

The effect of exposure to H2O2 on the lipopigments of the human sympathetic neurons was investigated by fluorescence and electron microscopy. In intact ganglia two subtypes of the lipopigment were seen: the yellow fluorescent pigment (emission maximum at 510 nm), which under the electron microscope had two components (vacuoles and osmiophilic matrix) and the orange fluorescent pigment (emission maximum at 535 nm), which in electron microscopy showed a third, highly osmiophilic component. Bleaching did not change the emission spectrum of the yellow pigment, while that of orange pigment shifted from 535 nm to 485 nm. Under electron microscopy the highly osmiophilic component disappeared in bleached orange pigment bodies. The characteristics of orange autofluorescent lipopigment are similar to those described for neuromelanin in the substantia nigra. The results suggest that neuromelanin accumulates in aging sympathetic neurons.

Aged↗

PubMed1986

Neuropeptide Y (NPY)-like immunoreactivity in rat sympathetic neurons and small granule-containing cells.

The distribution of neuropeptide Y-like immunoreactivity (NPY-LI) was examined in the rat superior cervical and hypogastric ganglia. NPY-LI was localized in the majority of the sympathetic neurons, a few small granule-containing (SGC) cells and nerve terminals. Most of the NPY-immunoreactive sympathetic neurons were also tyrosine hydroxylase (TH)-immunoreactive but in hypogastric ganglia few neurons with NPY-LI were devoid of TH-immunoreactivity. Electron microscopically NPY-LI was found in the Golgi complexes of sympathetic neurons, in large cytoplasmic granules (100-150 nm in diameter) of the SGC cells and in large dense-cored vesicles (80-100 nm in diameter) of the nerve terminals. NPY-LI coexists mainly with noradrenaline in sympathetic neurons, and may have regulatory functions in sympathetic ganglia and in target organs.

Animals↗

PubMed1986

Distribution of adrenergic innervation of blood vessels in peripheral nerve.

The distribution of adrenergic innervation of microvessels in the extrafascicular and endoneurial compartments of rat tibial nerve was examined with glyoxylic acid-induced and formaldehyde-induced histofluorescence methods. Periarterial and arteriolar adrenergic nerves were present in the epineurium-perineurium suggesting that blood flow in the extrafascicular connective tissue is under neurogenic influence. In contrast, blood vessels in the nerve endoneurium were not associated with histofluorescent nerve fibers. The absence of perivascular adrenergic innervation in the endoneurium suggests that regulation of vascular function within the endoneurium is not under neurogenic control.

Adrenergic Fibers↗

PubMed1986

Light and electron microscope demonstration of VIP- and enkephalin-immunoreactive nerves in the human male genitourinary tract.

Vasoactive intestinal polypeptide (VIP) and enkephalins were demonstrated in the nerves of the human male urogenital tract by light and electron microscope immunohistochemical techniques. Nerves containing immunoreactivity to VIP were more numerous than enkephalin-immunoreactive nerves. Both VIP- and enkephalin-immunoreactive nerves were detected in the vas deferens, prostate, seminal vesicles, and urinary bladder. In the kidney, testis, and epididymis no immunoreactive nerves could be demonstrated. By electron microscope both types of immunoreactivities were localized to the large granular vesicles of nerve terminals. VIP-immunoreactive nerves were mostly found subepithelially, whereas enkephalin-immunoreactive nerves were mainly related to smooth muscle cells. The possible functions of these peptide-containing nerves are discussed.

Aged↗

PubMed1986

Age related heterogeneity of lipopigments in human sympathetic ganglia.

The histochemical, autofluorescence and morphological characteristics of lipopigments accumulating with age in the human sympathetic neurons were studied. The spectral characteristics of the lipopigment autofluorescence change with age suggesting the accumulation of additional components in the residual bodies. This component is electron microscopically highly osmiophilic and stains also with silver staining. These changes may indicate the gradual melanization of the lipopigments due to auto-oxidation of catecholamines. The accumulation of the melanized form of lipopigment may be a sign of more advanced cellular trauma.

Adolescent↗

PubMed1986

The effect of sympathetic denervation with 6-hydroxydopamine on the ventral prostate of the rat.

The effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA) on the ventral prostate of the rat was studied. A dose of 50 mg/kg i.v., which was repeated after 1 week, was effective enough to produce total disappearance of sympathetic nerves. Reappearance of nerve fibres was evident 2 weeks after treatment. Dilation of prostatic alveoli was noted 1 week after denervation. It is concluded that the absence of normal sympathetic innervation prevents the emptying of the rat prostate.

Animals↗

PubMed1986

The effect of toluene inhalation exposure on catecholamine contents in rat sympathetic neurons.

Adult male rats were exposed to toluene in short-term exposure by inhalation for 48 h (2000 ppm, continuously), and in long-term inhalation for 3 months (1000 ppm, 8 h daily). The formaldehyde-induced fluorescence (FIF) technique for histochemical demonstration of catecholamines (CA) was used to detect changes in the catecholamine stores. The concentration of CA in the sympathetic neurons of superior cervical ganglia and adrenal medulla was measured by the FIF technique combined with microfluorimetry. The short-term toluene exposure induced a statistically significant reduction of CA contents in sympathetic neurons. After long-term exposure, no change in the CA level could be demonstrated either in sympathetic ganglion or adrenal medulla. In electron microscopic studies no clear pathological changes were detected after toluene exposure.

Adrenal Medulla↗

PubMed1985

Immunohistochemical localization of neurotensin in hamster adrenal medulla.

Neurotensin-like immunoreactivity was localized in nerve fibers and terminals of hamster adrenal medulla at light and electron microscopy using the peroxidase-antiperoxidase method. Numerous varicose neurotensin-immunoreactive nerves and terminals were found among nonlabeled cell groups situated peripherally in the adrenal medulla. Combined formaldehyde-glutaraldehyde (Faglu) fluorescence and immunohistochemistry of the same vibratome section showed that only norepinephrine cells were innervated by neurotensin-immunoreactive nerves. All norepinephrine cells seemed to be innervated by neurotensin-immunoreactive nerves. Neurotensin-immunoreactive nerves disappeared after extrinsic denervation of the adrenal gland. By electron microscopy numerous neurotensin-immunoreactive terminals were seen to make synaptic contacts with norepinephrine cells and with autonomic ganglion cells present in small numbers among norepinephrine cells. In the terminals neurotensin-like immunoreactivity was localized mainly in large dense-cored vesicles, but some precipitates were also associated with small vesicles, diffusely scattered in the axoplasm. The present findings suggest that in the hamster adrenal medulla part of the nerve terminals arising from splanchnic nerves contain neurotensin-like peptide. The functional significance of these nerves in the hamster adrenal medulla remains to be elucidated.

Adrenal Medulla↗

PubMed1985

Light- and electron-microscopic demonstration of enkephalin-like immunoreactivity in paraganglia of the human urinary bladder.

The distribution of enkephalin-like immunoreactivity in paraganglia of the urinary bladder of adult humans was studied by use of immuno-electron microscopy. All paraganglionic cells were positively stained. Enkephalin-like immunoreactivity was located in chromaffin granules. Chromaffin cells in the paraganglia showed only few degenerative features, suggesting undisturbed function of the cells.

Chromaffin System↗

PubMed1985

VIP like immunoreactive nerves in human respiratory tract. Light and electron microscopic study.

The present study provides light and electron microscopical evidence of Vasoactive Intestinal Peptide - (VIP) like immunoreactive nerves in human lower respiratory tract. Peroxidase antiperoxidase (PAP) technique was used to localize VIP-like immunoreactivity light microscopically and ultrastructurally. Under light microscopy, VIP-like immunoreactive nerves were observed in the smooth muscle layer of secondary bronchi to small bronchioli, and in bronchial glands. In addition, positive immunoreactive nervous network to VIP was found around nerve cell bodies in small microganglia. The bronchial epithelium of airway tract did not receive any VIP positive nerve fibers. Ultrastructurally VIP-like positive immunoreaction was localized in large granular vesicles ranging from 90 to 210 nm. Usually VIP-like positive immunoreactive nerve profiles contained several immunoreactive large vesicles (100-210). However, nerve profiles containing only a few positive large vesicles (80-150) were also observed. Under electron microscopy VIP-positive nerve profiles corresponded ultrastructurally to nerve profiles containing large granular vesicles observed in conventional electronmicroscopy. The present study provides new information about the innervation of human lower airway tract and widens the concept of their functional regulation on the anatomical basis reported here.

Bronchi↗

PubMed1985

Localization of enkephalins in adrenaline cells and the nerves innervating adrenaline cells in rat adrenal medulla.

The coexistence of met5- and leu5-enkephalin-like immunoreactivities with catecholamines in the rat adrenal medulla was studied with combined fluorescence microscopy and immunocytochemistry. Both met5- and leu5-enkephalin-like immunoreactivities were localized in few heavily stained adrenaline cells and in a population of nerves innervating adrenaline cells and as well as ganglion cells among the adrenaline cells. Only occasionally single noradrenaline cells exhibited light immunostaining for both enkephalins but no positive fibers could be found around the noradrenaline cells. In electron microscope the immunoreaction was seen in the granules of the adrenaline cells and in the large synaptic vesicles of the nerve terminals around the adrenaline cells. The present findings suggest that enkephalin-like immunoreactivity coexists mainly with adrenaline in rat adrenal medulla and that the enkephalin immunoreactive terminals regulate secretion of adrenaline from rat adrenal medulla.

Adrenal Medulla↗

PubMed1985

Indices of neurotransmitter synthesis and release in aging sympathetic nervous system.

Activities of tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and choline acetyltransferase (ChAT) were assayed in sympathetic ganglia and adrenal glands of young and aged Fischer-344 rats. The recovery of reserpine-depleted catecholamine stores and catecholamine loss following inhibition of synthesis and intraneuronal degradation also were assessed in sympathetic ganglia of young and aged rats. No age differences were observed in DBH activity of any tissues examined or in the activities of any enzymes in the coeliac-mesenteric ganglion complex. However, TH and ChAT activities were significantly higher in the superior cervical ganglia and adrenal glands of aged rats. In the hypogastric ganglion, only TH activity was higher in the old rats. Recoveries of reserpine-depleted catecholamine stores in the superior cervical and hypogastric ganglia of aged rats were slower than in young rats. Catecholamine loss following inhibition of synthesis and intraneuronal degradation was faster in the superior cervical ganglia but not in the hypogastric ganglia of old rats as compared with young rats. These findings suggest that neurotransmitter synthesis and release are enhanced with age in the superior cervical ganglion. The lack of age-related changes in the hypogastric ganglion might reflect the different cellular composition as well as the physiological role of this ganglion.

Adrenal Glands↗

PubMed1985

Immunohistochemical evidence for the occurrence of vasoactive intestinal polypeptide (VIP)-containing nerve fibres in human fetal abdominal paraganglia.

The abdominal paraganglia in man represent a major source of catecholamines, and perhaps peptide hormones, during the fetal period. The nature of the innervation of the abdominal paraganglia was studied immunohistochemically by utilising antibodies to vasoactive intestinal polypeptide, enkephalin, substance-P and somatostatin. The paraganglia showed an abundant network of VIP-immunoreactive fibres, and similar nerve fibres were found within nerve bundles of the preaortic sympathetic plexus. Occasionally, VIP-immunoreactive fibres were seen within the prevertebral ganglia, but stained cell bodies were never observed. It may be suggested that VIP-containing nerves could regulate a secretory response from fetal human abdominal paraganglia.

Chromaffin System↗

PubMed1985

Electron microscopic study on the innervation of the human lower respiratory tract: evidence of adrenergic nerves.

Samples of human lung were studied electron microscopically after fixation with glutaraldehyde and osmium tetroxide. Three different types of nerve profiles were found in the human lower respiratory tract. Type I nerve profiles contained small agranular vesicles 30-50 nm and large granular vesicles ranging from 60 nm to 210 nm. Type II nerve profiles contained small granular vesicles 30-50 nm and a few large granular vesicles ranging from 60 to 120 nm. Type III nerve profiles contained predominantly large irregular vesicles ranging from 60 to 210 nm, and only a few small agranular vesicles. The present electron microscopic results indicate that the smooth muscle layer of human bronchial tree receives adrenergic nerves.

Adrenergic Fibers↗

PubMed1984

Catecholamine-synthesizing enzymes in paraganglia of aged Fischer-344 rats. Immunohistochemistry and fluorescence microscopy.

The catecholamine-synthesizing enzymes, tyrosine hydroxylase, dopamine-beta-hydroxylase and phenylethanolamine-N-methyltransferase were examined by immunohistochemistry in hypertrophied paraganglia of aged male Fischer-344 rats. All paraganglionic cells reacted with antibodies against tyrosine hydroxylase. Dopamine beta-hydroxylase was identified in most paraganglionic cells, indicating that they synthesized norepinephrine. A variable number of paraganglia were positive for phenylethanolamine-N-methyltransferase, which suggested that they synthesized epinephrine. The formaldehyde-induced fluorescence method demonstrated greenish-yellow fluorescence or yellowish-brown fluorescence. The intensity of the fluorescence was in the same range as in adrenal medullary cells. The observations indicate that paraganglia are capable of synthesizing epinephrine.

Animals↗