Cerebral gangliosides in the treatment of peripheral neuronal diseases

Electromyographic study of diabetic and alcoholic polyneuropathic patients treated with gangliosides

A double-blind, randomized electromyographic investigation was conducted of the effects of cerebral ganglioside treatment on patients suffering from diabetic or alcoholic polyneuropathy. Cerebral gangliosides (50 mg once a day) administered to 15 diabetic and to 15 alcoholic neuropathic patients for 40 days, facilitated the reappearance of sensory potentials and significantly increased the MAP amplitude in median, ulnar, and peroneal nerves. In relation to ganglioside treatment, there was no significant change in the conduction velocities or in the distal latencies of these nerves, nor was there a change in the duration of the MAPs. On the basis of these results, it is suggested that the cerebral gangliosides are capable of inducing an improvement in the excitability of nerve fibers and of facilitating the processes of reinnervation, probably by means of an enhancement of fiber sprouting.

Murine leukemia. Proposed role for gangliosides in immune suppression

Glycolipid-bound sialic acid levels were elevated 2 to 4-fold in the sera of two strains of mice bearing thymic lymphoma produced either spontaneously (AKR/J) or due to chemical carcinogenesis [Swiss mice injected with 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboximide]. The serum glycolipid-bound sialic acid level reflected the tumor burden of the AKR/J mice during the early stages of leukemogenesis. Furthermore, the elevation was found to coincide with the ontogenesis of thymic lymphoma and not to be simply an age-dependent phenomenon. TLC analysis of Florisil column-purified gangliosides from the sera of AKR/J and Swiss mice suggested presence of gangliosides with mobilities very close to GM2 and GM3 standards respectively. On the premise that the elevated glycolipid levels in circulation might interfere with normal lymphocyte functions, the immunoinhibitory properties of exogenously added mixed gangliosides were examined on tests of in vitro correlates of the immune response. Gangliosides inhibited concanavalin A and lipopolysaccharide-induced [3H]-thymidine, [14C]-leucine and [3H]-lysine uptake by normal AKR/J mouse thymocytes and spleen cells. Mixed gangliosides also suppressed the two-way mixed lymphocyte reaction of AKR/J X Swiss and AKR/J X DBA/2 spleen cells. These and other results strongly suggest a general immunologically relevant role for gangliosides in the ontogeny of thymic lymphoma of mice.

Gangliosides and sialoglycoproteins in normal and denervated rat diaphragm muscle

Ganglioside-and glycoprotein-bound sialic acid in endplate and non-endplate regions of rat diaphragm muscles were assessed 1-16 days after phrenic nerve transection. Sialic acid in glycoproteins (90% of total) and gangliosides (10% of total) from intact hemidiaphragms was distributed uniformly throughout endplate and nonendplate regions. Afer denervation, the total sialic acid per hemidiaphragm increased (days 1-4) and reached a maximum level (days 8-12) which remained constant (days 12-16). These sialic acid changes reflected increments in gangliosides (40% over control), which occurred simultaneously in endplate and non-endplate regions (days 1-8), and increments in sialoglycoproteins (70%-80% over control), which took place much earlier in endplate (days 1-8) than in nonendplate (days 8-14) regions. The results of this study, together with previous data, favor the hypothesis that maintenance of both sialoglycoproteins and gangliosides depends upon an intact innervation, probably through separate mechanisms involving different neurogenic factors.