R. Stewart et al., LECTINS IMPLICATE SPECIFIC CARBOHYDRATE DOMAINS IN ELECTRIC-FIELD STIMULATED NERVE GROWTH AND GUIDANCE, Journal of neurobiology, 30(3), 1996, pp. 425-437
Both endogenous lectins and DC electric fields may control aspects of
early nerve growth and nerve guidance, To test whether such endogenous
cues interact, lectins of varying sugar affinity and valency were stu
died for effects on electric field induced growth and reorientation of
cultured Xenopus neurites, Concanavalin A (Con A), succinylated conca
navalin A(S-Con A), and wheat germ agglutinin all completely inhibited
field-induced cathodal reorientation, Lentil and pea lectins, which s
hare the same sugar affinity as Con A/S-Con A, were only partially eff
ective in inhibiting reorientation, Because S-Con A does not alter lat
eral mobility of membrane receptors, the previously accepted notion th
at Con A inhibited field-induced reorientation by preventing receptors
from translocating and becoming redistributed asymmetrically in the m
embrane may be oversimplified, There are likely to be additional steri
c interactions that Con A and S-Con A share that inactivate asymmetric
ally redistributed receptors and prevent reorientation, Additionally,
nerves growing in an applied field branch more commonly toward the cat
hode, Con A and S-Con A alone prevented this development of asymmetric
branching, All the lectins tested prevented the normal field-induced
increase in nerve growth rate, while all, except peanut agglutinin, pr
evented the usual faster growth cathodally than anodally. We suggest t
hat lectin interactions with electric field effects in vitro may invol
ve modulation of neuronal nicotinic acetylcholine receptors, neurotrop
hin receptors, or voltage-dependent calcium channels. Similar interact
ions between endogenous lectins and endogenous electric fields are to
be expected. (C) 1996 John Wiley & Sons, Inc.