Showing papers on "Toad published in 1967"
TL;DR: Three types of glial cells can be recognized on the basis of their form, the size and shape of the nucleus, and distinctive cytoplasmic characteristics when reconstructed from serial electron micrographs of the toad spinal cord.
Abstract: Three types of glial cells corresponding to astrocytes, oligodendrocytes, and microgliacytes were found in the toad spinal cord stained with a modification of the Golgi-Rio Hortega technique. Each can be correlated with a characteristic type of nucleus stained with toluidine blue.
209 citations
TL;DR: It is put forward, based on the results of pharmacological and surgical experiments, that the adrenergic nerves inhibit the release of the MSH from the pars intermedia of the toad.
Abstract: By means of a highly sensitive and specific histochemical method for the demonstration of certain biogenic monoamines a plexus of nerves containing a primary catecholamine has been demonstrated in the pars intermedia of the toad, Bufo arenarum. These nerves are restricted in distribution to the part of the gland which contains colloid vesicles (stored MSH ?) in the cells. The view is put forward, based on the results of pharmacological and surgical experiments, that the adrenergic nerves inhibit the release of the MSH from the pars intermedia. The origin of the nerves in the brain is unknown, but experiments with lesions have shown that it is not to be found in the nucleus periventricularis arcuatus.
61 citations
TL;DR: The findings obtained in this study suggest that monoamines may be transmitters in the toad spinal cord.
50 citations
43 citations
42 citations
TL;DR: It is anticipated that further study of the latter two groups of influences may provide insight into the specific roles of antidiuretic hormone and cyclic AMP in the chain of events leading from initial hormone-receptor interaction to final effect.
31 citations
TL;DR: Localization of catecholamines in the toad lung supports the pharmacological evidence for an adrenergic inhibitory innervation, with intramural inhibitory ganglion cells, and the action of nialamide suggests that monoamine oxidase is present in nerves containing adrenaline in theToad.
28 citations
TL;DR: A method for ureteral catheterization of the toad without need of surgical incision is described and it is postulated that hemorrhage causes a redistribution of lymph which restores the vascular volume.
23 citations
22 citations
TL;DR: In sections stained for adenosine triphosphatase bound to myofibrils, two types of intrafusal muscle fibers appear in spindles of both the cat and toad.
Abstract: Reduced nicotinamide adenine dinucleotide tatrazolium reductase is abundant in cat intrafusal muscle fibers, whereas in the toad its activity is equal to that in extrafusal fibers. Spindles of both species contain little fat. In sections stained for adenosine triphosphatase bound to myofibrils, two types of intrafusal muscle fibers appear in spindles of both the cat and toad.
21 citations
TL;DR: Cholinomimetic drugs, anticholinesterases and ACh antagonists were applied topically on the isolated toad spinal cord and the effects on ventral root reflex responses and the polarization levels in dorsal and ventral roots were recorded.
TL;DR: Experiments with ganglion-blocking and stimulating agents suggest that the cholinergic excitatory fibres to the toad lung are postganglionic, while many of the inhibitory adrenergic fibres are pre ganglionic.
TL;DR: It humis come to oumm mit temitiomi that a similar mmuethuod huas l)eemi uised for thin elect momi mmuicroscopic local izat iomi of heavy met als imi Panethu cells.
Abstract: thiat copper is quuamitntativehy remuiovnd froni tissmn sectiomis dunring the biistocheniical proceduume. Thuc demise deposits imu the copper-treated rat liver are comusidered to mnpresnmit sites rich imi copper, i mi ummukmuowmu formuu, at whuich silver has benmi deposited. Since the hiistochueniical mmmethod cami be umsed wit In suitable modificat iomi for ot hem mmunt als sumch as zimictmamid iromi, used of thin procnuluimn (In2 Simmcn thue complntiomi of this work, it humis come to oumm mit temitiomi that a similar mmuethuod huas l)eemi uised for thin elect momi mmuicroscopic local izat iomi of heavy met als imi Panethu cells (Muller amid Gever, Ada. Hi. stoe/mem. 21: 404. 1965).
TL;DR: It is clear that the specifity of the pseudoisocyanine method for islet insulin detection deserves further investigations, and the possibility is discussed that the amphiphil contain two hormones and that amphiphils in the toad represent transformations from D- to B-cells.
Journal Article•
TL;DR: The Xenopus lymphosarcoma agent is resistant to freezing-thawing, freeze-drying, and antibiotics, but sensitive to heat, ether, and chloroform.
Abstract: The Xenopus lymphosarcoma agent is resistant to freezing-thawing, freeze-drying, and antibiotics, but sensitive to heat, ether, and chloroform. It passes a 100-mµ filter, and remains in the supernatant fluid following centrifugation at 30,000 × g for 1 hr. The agent is passed from toad to toad through the water in which the Xenopus live.
Phytohemagglutinin injection did not alter the latent period following tumor homogenate injection, but did encourage more extensive metastasis. Thymectomized Xenopus developed tumors following tumor homogenate injection at least as quickly as did nonthymectomized controls.
Xenopus normal and tumor cells were cultured in vitro in a simple medium and in free gaseous exchange with the atmosphere. Cultured tumor cells retained the ability to induce tumors when injected into immature Xenopus, and cell-free medium from tumor tissue cultures also induced tumors.
TL;DR: The electron microscopic observation of the chemoreceptor of theCarotid labyrinth supports the view that the adrenergic transmission exists in the carotid chemosensory apparatus of the toad.
TL;DR: Adrenaline and noradrenaline mimic the action of the brachial plexus stimulation not only at the potential difference level but also at the flux level, suggesting hyperpolarization results from the activation of an active transport of potassium inwards and possibly from a diminution of the passive permeability of serous cell membranes.
01 Jan 1967
Journal Article•
Journal Article•
Journal Article•
01 Jul 1967