Summary
Experiments were performed to compare the permeability of capillaries supplying the endoneurial environment, which is invested by perineurium, with vascular permeability in the pulp where perineurium is absent. Anaesthetised rats were perfused through the aorta with physiological solutions containing lanthanum nitrate at 37° C. Pieces of inferior alveolar nerve and segments of mandibular incisors were immersion-fixed and transverse sections were examined electron microscopically for the distribution of lanthanum. In the pulp the nerve fibres pass between lanthanum-impermeable arterioles and venules en route to the incisal end. In the peripheral pulp a few capillaries were permeable but the most permeable capillaries lay between the odontoblasts. Pulpal capillary permeability was attributed to the fenestrated endothelium and contrasted with the unfenestrated endoneurial capillaries which were impermeable to lanthanum. Whereas the tight junctions of endoneurial capillaries are known to prevent certain blood-borne substances from entering the endoneurium, it was not clear whether the permeability of the pulpal capillaries, which are distant from the nerve fibres, could affect the nerve fibre environment. No extravasated lanthanum reached the pulpal nerve fibres suggesting that they are not affected. Technically it was not possible to examine the incisal third of the tooth where the situation could be different because the volume of the pulp decreases and capillaries lie closer to the nerve fibres.
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References
Adams D (1959) Peripheral capillaries in the rodent incisor pulp. J Dent Res 38:969–978
Altman PL, Dittmer DS (1972) Biology data book Vol 1, 2nd Edition Fed Am Soc Biol, Bethesda. p 446
Bishop MA (1981) A fine-structural survey of the pulpal innervation in the rat mandibular incisor. Am J Anat 160:213–229
Bishop MA (1982a) Fine-structural evidence on pulpo-dentinal sensory mechanisms as derived from the rat incisor and other teeth. In: Matthews B, Hill RG (eds) Anatomical physiological and pharmacological aspects of trigeminal pain. Elsevier, Amsterdam, pp 27–39
Bishop MA (1982b) A fine-structural investigation on the extent of perineurial investment of the nerve supply to the pulp in rat molar teeth. Arch Oral Biol 27:225–234
Bishop MA (1983) Permeability of rat incisor pulpal vessels to lanthanum. J Dent Res 62:429
Bishop MA (1984a) Vascular permeability to lanthanum in the rat incisor pulp and inferior alveolar nerve. J Anat 138:580
Bishop MA (1985) Evidence for tight junctions between odontoblasts in the rat incisor. Cell Tissue Res 239:137–140
Bundgaard M, Hagman P, Crone C (1983) The three-dimensional organisation of plasmalemmal vesicular profiles in the endothelium of rat heart capillaries. Microvasc Res 25:358–368
Clementi F, Palade GE (1969) Intestinal capillaries. I Permeability to peroxidase and Ferritin. J Cell Biol 41:33–58
Hayat MA (1970) Principles and techniques of electron microscopy. Biological applications Vol 1. Van Nostrand Reinhold, pp 111–112
Karnovsky MJ (1965) A formaldehyde-glutaraldehyde fixative of high osmolality for use in electron microscopy. J Cell Biol 27:137A
Krnjevic K (1954) The connective tissue of the frog sciatic nerve Q J Exp Physiol 39:55–72
Low FN (1976) The perineurium and connective tissue of peripheral nerve. In: Landon DN, The peripheral nerve. Chapman and Hall, London, pp 159–187
Machen TE, Erlij D, Wooding FBP (1972) Permeable junctional complexes. The movement of lanthanum across rabbit gallbladder and intestine. J Cell Biol 54:302–312
Moe H, Thorball N, Winther Nielsen H (1979) Structural alterations in proliferating, remodeling and regressing tooth pulp arterioles. Cell Tiss Res 203:339–354
Olsson Y, Reese TS (1971) Permeability of vasa nervorum and perineurium in mouse sciatic nerve studied by fluorescence and electron microscopy. J Neuropathol Exp Neurol 30:105–119
Renkin EM, Curry FE (1979) Transport of water and solutes across capillary endothelium. In: Giebisch G, Tosteson DC, Ussing H (eds) Membrane transport in biology Vol. IVA. Transport organs. Springer-Verlag, Berlin, pp 1–45
Weiss GB (1974) Cellular pharmacology of lanthanum. Ann Rev Pharmacol 14:343–354
Whittembury G, Rawlins FA (1971) Evidence of a paracellular pathway for ion flow in the kidney proximal tubule: Electromicroscopic demonstration of lanthanum precipitate in the tight junction. Pflügers Arch 330:302–309
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Bishop, M.A. Vascular permeability to lanthanum in the rat incisor pulp. Cell Tissue Res. 239, 131–136 (1985). https://doi.org/10.1007/BF00214912
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DOI: https://doi.org/10.1007/BF00214912