Adrenergic Structures Research Articles

Morphological manifestations of the dynamics of catecholamines binding by erythrocytes during activation and blockade of adrenergic regulatory mechanisms

Objective - to study, the dynamics of catecholamine binding on erythrocytes when modeling the stimulation and blockade of adrenergic regulation mechanisms using the cytological method
 Material and methods. The number of catecholamine granules on erythrocytes was determined using silver nitrate impregnation under conditions of administration of anapriline -adrenergic receptor blocker (2 mg/kg), acute stress, activation of noradrenergic systems (maprotiline, 10 mg/kg) and a combination of these effects.
 Results. The number of catecholamine granules in intact animals is 145-155 pieces/40 erythrocytes. Medium-sized granules are more common (0.6-0.9 m). After the administration of a -adrenergic receptor blocker, the total number of catecholamine granules decreases 2.8 times due to large and medium-sized granules. Under conditions of acute stress, the total number of granules increases almost 2 times due to small granules, which may be a sign of sensitization of erythrocyte membranes to catecholamines. Stimulation of the noradrenergic system causes a 20% decrease in the number of catecholamine granules due to a decrease in the number of small and medium sized granules. Under stress against the background of activation of the noradrenergic system, the number of granules on erythrocytes is reduced, which may be a sign of adrenergic receptor desensitization.
 Conclusions. The number of catecholamine granules on erythrocytes decreases after the administration of a -adrenergic receptor blocker and increases during acute stress. Stimulation of the noradrenergic system is accompanied by a decrease in the binding of catecholamines, especially under conditions of acute stress, which indicates desensitization of erythrocyte adrenergic receptors. The cytological method is sensitive enough to observe the reception of catecholamines by erythrocytes when exposed to adrenergic structures.

Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina).

Cholinergic and adrenergic innervation of the pancreas in chinchilla (Chinchilla Laniger Molina) was examined in this study. The pancreas is both an exocrine and endocrine gland with autonomic and sensory innervation presented by the numerous nerve fibers and small agglomerations of nerve cells. Investigations were performed on 16 adult chinchillas of both sexes. The material was collected immediately after death of the animals. Histochemical methods: AChE and SPG were used, in addition to routine technique of single and double immunohistochemical (IHC) staining using whole mount specimens and freezing sections with a thickness of 8 to 12 μm. In the immunofluorescence staining, primary antibodies directed against markers used to identify cholinergic - ChAT and VAChT, and adrenergic - DbH and TH neurons. Secondary antibodies were coupled to Alexa Fluor 488 and Alexa Fluor 555 fluorophores. Histochemical studies (AChE) revealed that chinchilla pancreatic cholinergic innervation consisted of ganglionic neurocytes and numerous nerve fibers. These structures are located in the parenchyma of the exocrine part of the organ in close proximity to blood vessels and are present within the walls of the pancreatic ducts and interstitial connective tissue. A delicate fiber network around the Langerhans islets was also observed. The most numerous cholinergic structures were found in the head and tail, and the least numbers were found in the body of the pancreas. The SPG method revealed that adrenergic fibers form a network in the adventitia of blood vessels, and individual fibers run throughout the pancreatic parenchyma. Moreover, adrenergic nerve fibers were observed around the ganglionic neurocytes. This innervation was similar in all parts of the investigated organ. IHC investigations allowed observations of both the cholinergic and adrenergic activities of autonomic nerve structures. Additionally, using ChAT/DbH double staining, colocalization of these substances was observed in the fibers of the pancreatic parenchyma that passed through the cholinergic ganglia. Colocalization of VAChT and TH was found in nerve fibers of the exocrine part, in the walls of blood vessels, and in individual nerve cells. Colocalization of ChAT/DbH and VAChT/TH was observed in the single nerve cells and in the small (2-3 cell) ganglia. ChAT- and DbH-immunopositive nerve fibers were found in the area of the islets of Langerhans. The results indicate a more intense cholinergic innervation of the chinchilla's pancreas, which is represented by both ganglia and nerve fibers, while adrenergic structures are mainly represented by fibers and only single neurocytes. This arrangement of the investigated structures in this species may imply a major role for hormonal control of exocrine secretion in rodents.

Effect of Doxazosin on Autonomic Nervous Control and Urodynamics of Rat Urinary Bladder during Modeled Infravesical Obstruction.

The therapeutic effect of doxazosin (40 μg/kg/day over one month) on urinary bladder was examined in female rats with modeled chronic infravesical obstruction (IVO) produced by graduated mechanical constriction of the proximal urethral segment. In one month, IVO induced a pronounced vesical hypertrophy both in treated and untreated rats that manifested in increased bladder weight and capacity, the latter increment being pronouncedly greater in treated rats. In untreated IVO rats, infusion cystometry revealed elevated basal intravesical pressure of void bladder P0, markedly increased maximal (premicturitional) pressure Pmax, and increased amplitude of spontaneous oscillations of intravesical pressure ΔPdet in filled bladder. Doxazosin produced no significant effect on Pmax rise during IVO, but prevented elevation of P0 and increment of ΔPdet in filled bladder. During gradual filling of urinary bladder in control (intact) rats, the parasympathetic vesical influences increased progressively, while in untreated IVO rats, the adrenergic influences prevailed even at maximal filling of the bladder. In IVO rats, doxazosin prevented the bias of the sympathetic-parasympathetic balance in the filled bladder in favor of sympathetic influences, but did not prevent this bias in a void bladder. It is hypothesized that α-adrenoblockers improve micturition during IVO caused by benign prostatic hyperplasia not only by decreasing the urethral resistance to urine flow due to down-regulation of prostate smooth muscle tone, but also by a direct action of these blockers on detrusor adrenergic receptors and central structures involved in urinary bladder control.

Вплив виключення бета1-адренорецепторів асоціативної кори дорослих щурів на автономну регуляцію серцевого ритму за умов зниженого атмосферного тиску

<p>Резюме. У літературі повідомляється про можливість блокування бета<sub>1</sub>-адренергічних рецепторів препаратом селективної дії небівололом [3]. Але немає даних про ефекти блокування бета<sub>1</sub>-адренорецепторів у асоціативних полях кори головного мозку на автономну регуляцію серцевого ритму. Водночас є можливість дозованого моделювання гіпобаричних і гіпоксичних умов в експерименті. Метою експерименту було виявити функціональні наслідки виключення бета<sub>1</sub>-адренорецепторів в асоціативній корі дорослих щурів за умов зниженого атмосферного тиску. В експерименті виключення бета<sub>1</sub>-адренорецепторів в асоціативній корі дорослих щурів за умов зниженого атмосферного тиску виявило залучення бета<sub>1</sub>-адренергічних структур досліджуваного лівого асоціативного кіркового поля до нейронних ланцюгів, які створювали парасимпатичний вплив на серцевий ритм, що відрізнялося від ефекту небівололу при нормальному атмосферному тиску.</p><p> </p>Ключові слова: бета<sub>1</sub>-адренергічні рецептори, автономна регуляція серцевого ритму, знижений атмосферний тиск.

The hTH-GFP reporter rat model for the study of Parkinson's disease.

Parkinson disease (PD) is the second leading neurodegenerative disease in the US. As there is no known cause or cure for PD, researchers continue to investigate disease mechanisms and potential new therapies in cell culture and in animal models of PD. In PD, one of the most profoundly affected neuronal populations is the tyrosine hydroxylase (TH)-expressing dopaminergic (DA) neurons of the substantia nigra pars compacta (SNpc). These DA-producing neurons undergo degeneration while neighboring DA-producing cells of the ventral tegmental area (VTA) are largely spared. To aid in these studies, The Michael J. Fox Foundation (MJFF) partnered with Thomas Jefferson University and Taconic Inc. to generate new transgenic rat lines carrying the human TH gene promoter driving EGFP using a 11 kb construct used previously to create a hTH-GFP mouse reporter line. Of the five rat founder lines that were generated, three exhibited high level specific GFP fluorescence in DA brain structures (ie. SN, VTA, striatum, olfactory bulb, hypothalamus). As with the hTH-GFP mouse, none of the rat lines exhibit reporter expression in adrenergic structures like the adrenal gland. Line 12141, with its high levels of GFP in adult DA brain structures and minimal ectopic GFP expression in non-DA structures, was characterized in detail. We show here that this line allows for anatomical visualization and microdissection of the rat midbrain into SNpc and/or VTA, enabling detailed analysis of midbrain DA neurons and axonal projections after toxin treatment in vivo. Moreover, we further show that embryonic SNpc and/or VTA neurons, enriched by microdissection or FACS, can be used in culture or transplant studies of PD. Thus, the hTH-GFP reporter rat should be a valuable tool for Parkinson's disease research.

Связанные с событием вызванные потенциалы мозга у пациентов с непсихотическими психическими расстройствами вследствие частичной потери зрения травматического генеза

Процесс частичной утраты зрения сопровождается негативными психопатологическими проявлениями, обусловленными дополнительным отягчающим влиянием посттравматического стресса на состояние психического здоровья человека. При прохождении пациентами МСЭК было проведено углубленное клинико-психопатологическое обследование 400 пациентов, в результате которого были сформированы две группы исследования: основная — 200 больных, у которых после травматического события, вызвавшего частичную потерю зрения, были диагностированы непсихотические психические расстройства, и группа сравнения — 200 человек, психическое состояние которых соответствовало так называемой условной норме. Субъективную оценку имеющихся клинико-психопатологических проявлений осуществляли с помощью опросника депрессии А.Т. Бека, методики диагностики самооценки реактивной и личностной тревожности Ч.Д. Спилбергера — Ю.Л. Ханина. Анализ объективных проявлений психопатологической симптоматики проводили с использованием клинических рейтинговых шкал депрессии и тревоги Гамильтона — НDRS и НАRS. В результате исследования выявлены характерные показатели связанных с событием слуховых вызванных потенциалов у больных с посттравматическим стрессовым расстройством. Время и корректность сенсомоторной реакции в исследуемых группах не отличались. Найдены достоверные корреляционные связи показателей слуховых вызванных потенциалов и показателей выраженности клинико-психопатологической симптоматики. Авторы предполагают участие адренергических структур неспецифических систем мозга, а также серотонинергических нейронов ядер шва в изменении паттерна вызванной электрической активности мозга.

Organization of the innervation of the oesophagus and stomach in chinchilla (Chinchilla laniger, Molina)

Using the histochemical and histological techniques the morphology and topography of the autonomic plexuses of the oesophagus and stomach in chinchilla (Chinchilla laniger) was investigated. AChE-positive and adrenergic structures in the myenteric and submucosal plexus were observed. According to the results the cholinergic structures were formed by the different in shape network meshes, various size of the neurons agglomerations and nerve fibres. Adrenergic fibres were found. Density of these structures varied in different parts of the investigated organs. This study is the first attempt to localize the intramural autonomic plexuses in this species.

Organisation of Autonomic Nervous Structures in the Small Intestine of Chinchilla (Chinchilla laniger, Molina)

Using histochemical, histological and immunocytochemical methods, organisation of the autonomic nerve structures in small intestine of chinchilla was investigated. Myenteric plexus was localised between circular and longitudinal layers of the smooth muscles. Forming network nodes, the small autonomic, cholinergic ganglia were linked with the bundles of nerve fibres. Adrenergic structures were visible as specific varicose, rosary-like fibres forming bundles of parallel fibres connecting network nodes. Structures of the submucosal plexus formed a finer network than those of the myenteric plexus. Moreover, in 'whole-mount' specimens, fibres forming thick perivascular plexuses were also observed. Immunocytochemical studies confirmed the cholinergic and adrenergic character of the investigated structures. VAChT-positive neurones were found only in myenteric plexus, and numerous VAChT-positive and DBH-positive fibres were found in both plexuses.

P.1.023 Survival role of embryonal proteins in Alzheimer's disease linked dementia via regulation of oxidative stress and level of catecholamines

Purpose of the study: Main event in the pathogenesis of such a neurodegenerative disorder as Alzheimer’s disease (AD) is generation and deposition of amyloid beta (Ab). Oxidative stress and generation of free radical species have implications in the formation of Ab and its subsequent neurotoxicity. Degeneration of aminergic brainstem nuclei such as the locus coeruleus which is very vulnerable to the free radicals and the selective exhaustion of catecholamines near the locus coeruleus of brainstem can appear as a potential pathogenesis of AD. That’s why our study was focussed to find some parallels between oxidative stress and changes in catecholamines concentration experimental model of AD, and find new biological agents which will be able to regulate them. As a bioregulator we chose the complex of proteoglycans of embryonal genesis (PEG). PEG contains the pool of proteoglycans of embryonal genesis which are associated with alphafetoprotein, chorionic gonadotrophin, beta1-glycoprotein, carcinoembryonic antigen, and the carbohydrate antigens Ca-19−9 and Ca-125. Methods used: The experimental model of AD was made in rats by intracerebroventricular injection of aggregated Ab (fragment 25−35). The animals were divided into five groups: the control group consisted of vehicle-treated animals; the 1st experimental group (PEG-control) was subcutaneously injected with PEG (0.5mg/100 g) only; the 2nd experimental group was i.c.v. injected with aggregated Ab; the 3rd experimental group was subcutaneously injected with PEG (0.5mg/100 g) 7 days before Ab injection (group PEG-1); the 4th experimental group was subcutaneously administered PEG (0.5mg/100 g) 7 days before Ab injection and on the 31st day after it (group PEG-2). Oxidative stress and antioxidant capacity were measured by use of chemoluminescence method (spontaneous, induced by UV and Fe2+ ions) in cerebral cortex, hippocampus and brainstem. Adrenergic structures of brainstem were studied by glyoxylic acid condensation using luminescence microscope and accompanied by the HPLC study of norepinephrine (NE) and metabolites of adrenergics. Summary of results and Conclusion: After injection of Ab received data testify the increase in the level of chemoluminescence (both spontaneous and inducible) in the cerebral cortex, hippocampus and brainstem. On the other hand the increase in intensity of luminescence of catecholamine granules near the locus coeruleus was also detected. At the same time HPLC results show high elevation in concentration of NE in the brainstem. In PEG treated animals all types of chemoluminescence in mentioned brain structures decreased and the antioxidant capacity increased without any significant difference between PEG-1 and PEG-2 groups. Almost no changes of adrenergic structures were shown compared with the control rats in all PEG treated groups. At the same time in PEG-1 group concentration of NE was less than in control, whereas in PEG-2 group it was about control level. It should be certainly pointed that the results of biochemical determination of NE and metabolites of monoamines in brainstem were in unison with the luminescent study. Summarising, it seems that regulation of oxidative stress and disturbance in adrenergic structures can be of importance for neuronal rescue in Alzheimer’s pathology and regulation of these both processes can lead to neuroprotection.

Distribution and morphology of the catecholaminergic neural elements in the human hypothalamus

Previous studies have demonstrated that catecholaminergic, tyrosine hydroxylase (TH)-immunoreactive (IR) perikarya and fibers are widely distributed in the human hypothalamus. Since TH is the key and rate-limiting enzyme for catecholaminergic synthesis, these IR neurons may represent dopaminergic, noradrenergic or adrenergic neural elements. However, the distribution and morphology of these neurotransmitter systems in the human hypothalamus is not entirely known. Since the different catecholaminergic systems can be detected by identifying the neurons containing the specific key enzymes of catecholaminergic synthesis, in the present study we mapped the catecholaminergic elements in the human hypothalamus using immunohistochemistry against the catecholaminergic enzymes, TH, dopamine beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT). Only a few, PNMT-IR, adrenergic neuronal elements were found mainly in the infundibulum and the periventricular zone. DBH-IR structures were more widely distributed in the human hypothalamus occupying chiefly the infundibulum/infundibular nucleus, periventricular area, supraoptic and paraventricular nuclei. Dopaminergic elements were detected by utilizing double label immunohistochemistry. First, the DBH-IR elements were visualized; then the TH-IR structures, that lack DBH, were detected with a different chromogen. In our study, we conclude that all of the catecholaminergic perikarya and the majority of the catecholaminergic fibers represent dopaminergic neurons in the human hypothalamus. Due to the extremely small number of PNMT-IR, adrenergic structures in the human hypothalamus, the DBH-IR fibers represent almost exclusively noradrenergic neuronal processes. These findings suggest that the juxtapositions between the TH-IR and numerous peptidergic systems revealed by previous reports indicate mostly dopaminergic synapses.

Autonomic Innervation of Pancreas in Egyptian Spiny Mouse (Acomys cahirinus, Desmarest)

The aim of the study was to obtain details of the morphology of the autonomic innervation of pancreas. Six adult Egyptian spiny mice (Acomys cahirinus, Desmarest) were studied for the presence and location of autonomic fibres and cells in the pancreas. The macromorphological investigations were performed using the thiocholine method adapted for this type of specimens. For processing tissues two histochemical techniques were used: thiocholine method on activity of AChE and the glyoxylic acid method for adrenergic structures. Cholinergic fibres and small autonomic ganglia were found among the secretory sections and along the pancreatic duct and both pancreaticoduodenal arteries, and its branches, reaching the Langerhans islets and forming around them a kind of net. From 24 to 40 AChE-positive ganglions in the whole exocrine part were observed. The highest density of cholinergic fibres was observed in the head of pancreas. Numerous adrenergic fibres that accompanied blood vessels as well as interlobular and intralobular ducts were found inside the exocrine parts of the pancreas. Neither adrenergic cells or adrenergic fibres were observed inside the pancreatic islets. Our results can be used in comparative anatomy studies of pancreas in mammals.

Adrenergic Regulation of Erythropoiesis during Cytostatic-Induced Myelosuppressions

The role of central adrenergic structures in the regulation of the erythroid hematopoietic stem was studied during administration of cyclophosphamide and 5-fluorouracil. The central nervous system contributed to suppression of erythropoiesis during cytostatic treatment. The suppressive effect of brain adrenergic structures on the erythron after treatment with cyclophosphamide and 5-fluorouracil was related to dysfunction of adherent cells in the hemopoiesis-inducing microenvironment (formation of hemopoietic islets and secretion of erythropoietic activity) and production of growth factors by myelokaryocytes, respectively. Brain norepinephrine had an inhibitory effect on proliferative activity and differentiation of erythroid precursors that were associated with the erythropoietin and peripheral alpha-adrenergic structures. However, stimulation of beta-adrenergic structures was followed by an increase in the rate of erythroid cell maturation.

Role of central adrenergic structures in the regulation of granulocytopoiesis during cytostatic treatment

We studied the role of central adrenergic structures in the regulation of granulocytic hemopoietic stem during cytostatic treatment. It was found that brain norepinephrine promoted the decrease in functional activity of adherent mononuclears of the hemopoiesis-inducing environment, cytokine-dependent and alpha-adrenergic mechanisms of regulation of division and maturation of granulomonocytic precursors under conditions of cyclophosphamide treatment. Under conditions of 5-fluorouracil treatment, the effect of the adrenergic system was aimed at the formation of granulocytic and fibroblast-type cell complexes, activation of the production of colony-forming activity by microenvironmental cells, and acceleration of maturation of neutrophilic granulocytes associated with the system of granulocytic CSF and peripheral alpha-adrenergic structures.

Monoaminergic Regulation of the Pool of Erythropoietic Stem Cells in Active and Passive Mouse in Experimental Neuroses

We studied monoaminergic mechanisms of regulation of the pool of erythropoietic precursors in active and passive mice under conditions of conflict situation and during paradoxical sleep deprivation. It was found that in animals with different behavior subjected to experimental neuroses the regulatory effects of CNS monoamines on proliferation and differentiation are mediated via adrenergic and erythropoietin-sensitive structures on erythroid stem cells. The revealed intergroup differences in precursor proliferation and differentiation rates (and erythrokaryocyte content in the bone marrow) are related to peculiarities in the activity of monoaminergic system and their interaction with peripheral structures on erythropoietic precursors.

Mechanisms of Regulation of Erythropoiesis during Experimental Neuroses

We studied the mechanisms of erythropoiesis regulation in a conflict situation and during paradoxical sleep deprivation. Plastic reconstruction of the erythroid hemopoietic stem during experimental neuroses is regulated by a complex multicomponent and multilevel system. This system consists of central adrenergic structures, sympathetic part of the autonomic nervous system, and alpha- and beta-adrenoceptors on erythroid precursors and cells of the hemopoietic microenvironment. Erythroid cells receive instructive information from the central nervous system via adrenoceptors on cells of the hemopoiesis-inducing microenvironment and erythroid precursors. Hyperplasia (conflict situation) and suppression of erythropoiesis (paradoxical sleep deprivation) are associated with specificity of central adrenergic regulatory mechanisms.

Character of Viscero- and Somatomotor Interactions in Rat Pups at Changes of the Level of Activity of Adrenergic Structures

In the 5–10-day old rat pups, in the course of simultaneous recording of ECG, respiration rate (RR), and spontaneous periodic motor activity (SPMA) there were determined parameters of the studied processes and their correlations at changes of levels of activity of adrenergic structures. As adrenoactive agents, the sympathomimetic amphetamine, α- and β-adrenolytics phentolamine and propranolol, as well as the dopamine receptor blocker haloperidol were used. It has been established that injection of amphetamine significantly increases intensity of the decasecond rhythm in the activity pattern of excitable structures. However, the action both on the α- and β-adrenoreceptors and on dopamine receptors produces no significant changes of this rhythm parameters. Based on this, it can be suggested that an increase of the decasecond rhythm is due to the ability of amphetamine to inhibit the pentose phosphate cycle activity. Administration of adrenolytics decreases RR and heart rate (HR). Amphetamine restores them by a simultaneous increase of pathological disturbances of the respiration rhythm, which appear at injections of sympatholytics. Blockade of dopamine receptors leads to replacement of motor activity fires by jerks following in the rhythm close to the previous one. As a rule, at the blockade of α-adrenoreceptors the SPMA pattern is deprived of obvious rhythmic components, whereas at the blockade of β-adrenoreceptors, they are preserved. Analysis of the obtained data indicates that the respiration frequency modulation that increases at action on adrenoreactive structures correlates with the motor activity changes. However, there are several peculiarities due to action on various types of adrenoreceptors. Of the leading significance in the normal intersystem interaction is preservation of balance between individual adrenergic structures.

Effects of norepinephrine and epinephrine on resting membrane potential in body wall muscle cells of Lumbricus terrestris earthworm.

Norepinephrine and to a lesser extent epinephrine increased the resting membrane potential of earthworm body wall muscle cells. Ouabain, phentolamine, propranolol, and replacement of Ca(2+) with Mg(2+) in the incubation medium abolished this effect. External 3'5'-cAMP in high concentration, dibutyryl cAMP, and dibutyryl cGMP did not induced hyperpolarization of muscle cell membranes. It was concluded that norepinephrine and epinephrine increased the resting membrane potential in earthworm body wall muscle cells via activation of Na(+), K(+) pump. This process involves Ca(2+) and sarcolemmal adrenergic structures, similar to alpha-adrenoceptors in vertebrate, but not the cyclic nucleotide systems.

Adrenergic structures, M-cholino- and β-adrenoception in thyroid gland of desympathized rats during postnatal ontogenesis

The density of adrenergic nerve terminals in thyroid gland decreases with age, and this decrease is more pronounced in parafollicular terminals. Density of3H-dihydroalprenolol binding sites increases in 1-month-old rats and decreases in senescent rats. In comparison with control rats, in sympathetically denervated rats the density of nerve fibers increases at the age of 1–6 months and decreases at the age of 12 months. Binding of3H-dihydroalprenolol is considerably higher in immature sympathetically denervated rats.

Comparative single and double immunolabelling with antisera against catecholamine biosynthetic enzymes: criteria for the identification of dopaminergic, noradrenergic and adrenergic structures in selected rat brain areas

Immunodetection of catecholamine biosynthetic enzymes is frequently used for the visualization of central nervous catecholaminergic systems. Because of the method's limited specificity for the different catecholamines, interpretation of the results often presents difficulties. To determine criteria for the identification of dopaminergic, noradrenergic, and adrenergic afferents to the rat amygdaloid complex, comparative immunolabelling for tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), and phenylethanolamine-N-methyl-transferase (PNMT) was carried out using single- and double-labelling for fluorescence, light- and electron microscopy. The observations were complemented by findings in brainstem and hypothalamic areas. The results indicated that TH-labelling detected preferentially dopaminergic afferents in the lateral central and intercalated amygdaloid nuclei. DBH-labelling detected noradrenergic axons in nuclei lacking PNMT-immunoreactive fibres, and PNMT was a marker for adrenergic axons in the entire complex. For nuclei with combined dense dopaminergic, noradrenergic and/or adrenergic innervation, morphological and immunolabelling characteristics were described which, to a certain extent, enabled identification of the different afferents in anti-TH or anti-DBH-preparations. Using a monoclonal TH-antiserum, noradrenergic and adrenergic axons displayed weaker immunoreactivity than dopaminergic ones, and possessed characteristic morphological features. TH-immunoreactivity in noradrenergic axons differed depending on their origin, and showed intra-axonal compartmentalization. The present study provides a basis for the use of the detection of biosynthetic enzymes in future investigations into the ultrastructure and connectivity of the catecholaminergic amygdala innervation.

Changes in pre- or postsynaptic adrenergic mechanisms modify the thermoregulatory responses produced by pyrogen in rabbits

1. 1. Thermoregulatory responses to BHT 920, prazosin (PRA) and 6-hydroxydopamine (6-OHDA) were investigated in pyrogen (lipopolysaccharide Escherichia coli, LPS) treated rabbits. 2. 2. All the compounds in question, despite their different selectivity for pre- or postsynaptic adrenergic structures, significantly reduced pyrogen fever. Antipyresis was associated with inhibition of the metabolic rate. 3. 3. The role of adrenergic mechanisms in fever, with particular respect to those of postsynaptic alpha-2, is discussed.