Effect of intraocular pressure on rapid axoplasmic transport in monkey optic nerve.

Tritiated leucine was injected into the vitreous of owl monkeys (Aotus trivirgatus) to make it available to retinal ganglion cells for protein synthesis. Intraocular pressure was maintained for eight hours at selected levels between 15 and 105 mm. Hg. Autoradiography and scintillation counting were used to follow the movement of the labeled protein along the axons from the retinal ganglion cells to the lateral geniculate nucleus (LGN) by axoplasmic transport. At normal levels of intraocular pressure, label was distributed continuously along the retina, optic disc, and nerve, and radioactive label reached the LGN by eight hours. When the intraocular pressure was moderately elevated there was partial obstruction of axoplasmic transport in the region of the lamina cribrosa, but some label reached the optic nerve and LGN. When intraocular pressure was elevated to within 25 mm. Hg of mean blood pressure, there was complete obstruction of transport at the lamina cribrosa and label did not reach the LGN; retinal synthesis and transport along the axons to the optic nerve head continued. When the intraocular pressure approached or exceeded mean blood pressure, retinal synthesis stopped, as evidenced by absence of label in both the retina and disc. Our conclusions are that: (1) axoplasmic transport is affected by intraocular pressure, (2) there is a selective effect deep in the optic nerve head at the lamina cribrosa, and (3) a partial effect can be detected even at moderate elevations of intraocular pressure. Whether the obstruction is mechanical or is secondary to reduced blood flow has not been determined, and the exact relevance of these findings to the pathogenic mechanisms of glaucomatous cupping is not yet clear.

[1]  G. A. Kerkut,et al.  The transport of 14C-labelled material from CNS to and from muscle along a nerve trunk. , 1967, Comparative Biochemistry and Physiology A.

[2]  B. Grafstein Axonal transport: communication between soma and synapse. , 1969, Advances in biochemical psychopharmacology.

[3]  J. Diamond,et al.  Evidence that axoplasmic transport of trophic factors is involved in the regulation of peripheral nerve fields in salamanders , 1973, The Journal of physiology.

[4]  D. R. Anderson Ultrastructure of human and monkey lamina cribrosa and optic nerve head. , 1969, Archives of ophthalmology.

[5]  S Ochs,et al.  Fast transport of materials in mammalian nerve fibers. , 1972, Science.

[6]  J. Sjöstrand,et al.  Axonal transport of proteins in retinal ganglion cells. Characterization of the transport to the superior colliculus. , 1972, Brain research.

[7]  C. Sotelo,et al.  Cytological aspects of the axonal migration of catecholamines and of their storage material. , 1973, Brain research.

[8]  B. Droz,et al.  THE TURNOVER OF PROTEINS IN AXONS AND NERVE ENDINGS , 1969 .

[9]  G. Gross,et al.  Fast axonal transport in the c-fibers of the garfish olfactory nerve. , 1973, Journal of neurobiology.

[10]  A. Hendrickson Electron microscopic distribution of axoplasmic transport , 1972, The Journal of comparative neurology.

[11]  H. Hansson Uptake and intracellular bidirectional transport of horseradish peroxidase in retinal ganglion cells. , 1973, Experimental eye research.

[12]  A. Hendrickson,et al.  Changes in the rate of axoplasmic transport during postnatal development of the rabbit's optic nerve and tract. , 1971, Experimental neurology.

[13]  B. Droz Renewal of synaptic proteins. , 1973, Brain research.

[14]  M. Perišic,et al.  Synaptic Transmission Depressed by Colchicine Blockade of Axoplasmic Flow , 1972, Science.

[15]  C. Sandri,et al.  Contributions of Axoplasmic Transport to Synaptic Structures and Functions , 1972 .

[16]  K. Kristensson,et al.  Retrograde axonal transport of protein. , 1971, Brain research.

[17]  J. Sjöstrand,et al.  The effect of colchicine on the axonal transport of protein in the optic nerve and tract of the rabbit. , 1969, Brain research.

[18]  A. Hendrickson,et al.  Staining for autoradiography of the central nervous system. , 1972, Stain technology.

[19]  Telford Jn The expandable loop: an improved wire-loop device for producing thin photographic films suited to autoradiographic electron microscopy. , 1969 .

[20]  M. Byers Structural correlates of rapid axonal transport: evidence that microtubules may not be directly involved. , 1974, Brain research.

[21]  D. Mayor,et al.  An electron microscopic study of the early changes proximal to a constriction in sympathetic nerves , 1969, Proceedings of the Royal Society of London. Series B. Biological Sciences.

[22]  S. M. Chou,et al.  Axoplasmic flow rates in the monkey optic system , 1970, Neurology.

[23]  J. Lavail,et al.  A method based on retrograde intraaxonal transport of protein for identification of cell bodies of origin of axons terminating within the CNS. , 1973, Brain research.

[24]  A. H. Bunt Effects of vinblastine on microtubule structure and axonal transport in ganglion cells of the rabbit retina. , 1973, Investigative ophthalmology.

[25]  J. Telford The expandable loop: an improved wire-loop device for producing thin photographic films suited to autoradiographic electron microscopy. , 1969, Stain technology.

[26]  R. Lasek Protein Transport in Neurons , 1970 .

[27]  B. R. Fink,et al.  Effects of lidocaine on axonal morphology, microtubules, and rapid transport in rabbit vagus nerve in vitro. , 1973, Journal of neurobiology.

[28]  A. Hendrickson,et al.  Electron Microscopic Radioautography: Identification of Origin of Synaptic Terminals in Normal Nervous Tissue , 1969, Science.

[29]  A. Dahlstrom Axoplasmic Transport (with Particular Respect to Adrenergic Neurons) , 1971 .

[30]  B. R. Fink,et al.  Lidocaine Inhibition of Rapid Axonal Transport , 1972, Anesthesiology.

[31]  J. Lavail,et al.  Retrograde Axonal Transport in the Central Nervous System , 1972, Science.

[32]  F. Samson,et al.  AXOPLASMIC TRANSPORT IN THE CRAYFISH NERVE CORD The Role of Fibrillar Constituents of Neurons , 1971 .

[33]  D. Worthen,et al.  Histology of the Human Eye. , 1972 .

[34]  B. Grafstein,et al.  Accumulation of radioactive protein in mouse cerebral cortex after injection of 3H-fucose into the eye. , 1973, Experimental neurology.