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  • 1
    Electronic Resource
    Electronic Resource
    Resistance of adrenergic neurotransmission in the toad heart to adrenoceptor blockade (1981)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 317 (1981), S. 331-338 
    Details
    ISSN: 1432-1912
    Keywords: Amphibian heart ; Adrenoceptors ; Propranolol ; Adrenaline ; Neurotransmission
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stimulation of sympathetic nerves to the toad heart produced increases in both the rate and force of cardiac beat. Although these responses were abolished by treatment with bretylium (10−6 mol ·l−1) or 6-hydroxydopamine (100 mg·kg−1), and surgical sympathetic denervation, they were not abolished by treatment with propranolol (10−6 mol·l−1) and phentolamine (3×10−6 mol·l−1), either alone or in combination. The responses remaining after adrenoceptor blockade could not be ascribed to the effects of neurally released dopamine, ATP, adenosine, histamine or a variety of neuropeptides, although the participation of an as yet unidentified co-transmitter cannot be ruled out. Quantitative analysis of the interactions between propranolol and adrenaline on cardiac adrenoceptors, after blockade of α-receptors and amine uptake mechanisms, revealed that these interactions do not comply with the conditions for simple competitivity. Therefore, in addition to its action on β-receptors, adrenaline seems to be producing excitation of the toad heart by acting on adrenoceptors which cannot be classified as either α-or β-receptors. These results, together with the existence of close neuromuscular gaps (〈50nm) in the toad heart, are consistent with the hypothesis that sympathetic excitation of the toad heart is mediated by both “extra-junctionl” β-adrenoceptors, and “junctional” adrenoceptors which are neither α-nor β-receptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00501315
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  • 2
    Electronic Resource
    Electronic Resource
    Catecholamines and catecholamine-synthesizing enzymes in guinea-pig sensory ganglia (1990)
    Springer
    Cell & tissue research 261 (1990), S. 595-606 
    Details
    ISSN: 1432-0878
    Keywords: Sensory ganglia ; Catecholamines ; Catecholamine-synthesizing enzymes ; Tyrosine hydroxylase ; Sympathetic innervation ; Neuropeptide immunocytochemistry ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cranial and spinal sensory ganglia of the guinea-pig were investigated by means of histochemistry and biochemistry for the presence of catecholamines and catecholamine-synthesizing enzymes. Sensory neurons exhibiting immunoreactivity to the rate-limiting enzyme of catecholamine synthesis, tyrosine nydroxylase (TH), were detected by immunohistochemistry in lumbo-sacral dorsal root ganglia, the nodose ganglion and the petrosal/jugular ganglion complex. The carotid body was identified as a target of TH-like-immunoreactive (TH-LI) neurons by the use of combined retrograde tracing and immunohistochemistry. Double-labelling immunofluorescence revealed that most TH-LI neurons also contained somatostatin-LI, but TH-LI did not coexist with either calcitonin gene-related peptide- or substance P-LI. TH-LI neurons did not react with antibodies to other enzymes involved in catecholamine synthesis, i.e., aromatic amino acid decarboxylase (AADC), dopamine-β-hydroxylase (DβH), and phenylethanolamine-N-methyltransferase (PNMT). Petrosal neurons as well as their endings in the carotid body lacked dopamine- and L-DOPA-LI. Sensory neurons did not display glyoxylic acid-induced catecholamine fluorescence. Ganglia containing TH-LI neurons were kept in short-term organ culture after crushing their roots and the exiting nerve in order to enrich intra-axonal transmitter content at the ganglionic side of the crush. However, even under these conditions, catecholamine fluorescence was not detected in axons projecting peripherally or centrally from the ganglia. Sympathetic noradrenergic nerves entered the ganglia and terminated within them. Accordingly, biochemical analyses of guinea-pig sensory ganglia revealed noradrenaline but no dopamine. In conclusion, catecholamines within guinea-pig sensory ganglia are confined to sympathetic nerves, which fulfill presently unknown functions. The TH-LI neurons themselves, however, lack any additional sign of catecholamine synthesis, and the presence of enzymatically active TH within these neurons is questionable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00313540
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  • 3
    Electronic Resource
    Electronic Resource
    Peptide-containing nerves in the urinary bladder of the toad, Bufo marinus (1983)
    Springer
    Cell & tissue research 229 (1983), S. 137-144 
    Details
    ISSN: 1432-0878
    Keywords: Peptide-containing nerves ; Urinary bladder ; Toad (Bufo marinus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distributions of peptide-containing nerves in the urinary bladder of the toad, Bufo marinus, were studied by means of fluorescence immunohistochemistry of whole-mount preparations. The bundles of smooth muscle in the bladder are well supplied by varicose nerve fibres displaying somatostatin-like immunoreactivity; these fibres probably arise from intrinsic perikarya. The urinary bladder also has a well-developed plexus of nerves containing substance P-like immunoreactive material; these elements probably represent sensory nerves of extrinsic origin. Nerve fibres showing immunoreactivity to vasoactive intestinal polypeptide (VIP) or enkephalin are rare within the urinary bladder of the toad. It is considered unlikely that any of these peptides directly mediates the hyoscine-resistant excitatory response of the smooth muscle to nerve stimulation in the toad bladder.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217886
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  • 4
    Electronic Resource
    Electronic Resource
    Lack of correlation between ultrastructural and pharmacological types of non-adrenergic autonomic nerves (1982)
    Springer
    Cell & tissue research 221 (1982), S. 551-581 
    Details
    ISSN: 1432-0878
    Keywords: Non-adrenergic, non-cholinergic nerves ; Cholinergic nerves ; Ultrastructure ; Nervous transmission
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to test the premise that non-adrenergic, non-cholinergic (NANC) autonomic nerves have a distinctive ultrastructural appearance, clearly different from that of cholinergic nerves, a detailed quantitative ultrastructural analysis has been made of the non-adrenergic innervation of 15 tissues thought from pharmacological evidence to be innervated by NANC nerves (rat and rabbit anococcygeus muscles; rabbit hepatic portal vein; extrinsically denervated toad lung); cholinergic nerves (atria of rat, rabbit, guinea-pig and toad); or both (guinea-pig cervical and thoracic trachealis muscle; rabbit rectococcygeus muscle; urinary bladder of rat, rabbit, guinea-pig and toad) in addition to their adrenergic supply. Following fixation with a modified chromaffin procedure allowing identification of adrenergic nerves, large, randomly selected samples of non-adrenergic nerve profiles from each tissue were analysed with respect to numbers, relative proportions, and size frequency distributions of different vesicle classes within the profiles. The neuromuscular relationships within each tissue were also analysed. On the basis of these analyses, it is clear that there are no consistent ultrastructural differences between cholinergic and NANC autonomic nerves: neither proportions nor sizes of the vesicles provide any clue as to the transmitter used by a particular nerve. The great majority of nerve profiles, whether cholinergic or NANC, contain predominantly small clear “synaptic” vesicles. Large filled “peptidergic” vesicles are no more common in most NANC nerves than in most cholinergic ones. It is concluded, on ultrastructural grounds, that the primary transmitter in these NANC autonomie nerves is most likely to be stored in and released from the small clear vesicles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00215701
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  • 5
    Electronic Resource
    Electronic Resource
    Innervation of the renal vasculature of the toad (Bufo marinus) (1983)
    Springer
    Cell & tissue research 231 (1983), S. 357-376 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Amphibia ; Vasculature ; Innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the dorsal aorta and renal vasculature in the toad (Bufo marinus) has been studied with both fluorescence and ultrastructural histochemistry. The innervation consists primarily of a dense plexus of adrenergic nerves associated with all levels of the preglomerular vasculature. Non-adrenergic nerves are occasionally found in the renal artery, and even more rarely near the afferent arterioles. Many of the adrenergic nerve profiles in the dorsal aorta and renal vasculature are distinguished by high proportions of chromaffin-negative, large, filled vesicles. Close neuromuscular contacts are common in both the renal arteries and afferent arterioles. Possibly every smooth muscle cell in the afferent arterioles is multiply innervated. The glomerular capillaries and peritubular vessels are not innervated, and only 3–5% of efferent arterioles are accompanied by single adrenergic nerve fibres. Thus, nervous control of glomerular blood flow must be exerted primarily by adrenergic nerves acting on the preglomerular vasculature. The adrenergic innervation of the renal portal veins and efferent renal veins may play a role in regulating peritubular blood flow. In addition, glomerular and postglomerular control of renal blood flow could be achieved by circulating agents acting via contractile elements in the glomerular mesangial cells, and in the endothelial cells and pericytes of the efferent arterioles. Some adrenergic nerve profiles near afferent arterioles are as close as 70 nm to distal tubule cells, indicating that tubular function may be directly controlled by adrenergic nerves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222187
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