The effect of mixed bovine brain gangliosides on hypoxic conduction block in control and streptozotocin-diabetic rats.
This study describes the electrophysiological responses of endoneurial preparations derived from rat sciatic nerve to acute hypoxia in vitro. Preparations from control rats exhibited a 40% decline in compound action potential (CAP) amplitude after 40 min exposure to medium gassed with 8% O2. In preparations from 4 week streptozotocin-diabetic rats CAP declined by only 29%, indicating a resistance to hypoxic conduction blockade. Treating diabetic rats with mixed bovine brain gangliosides (10 mg/kg/day i.p.) exaggerated this resistance to hypoxic conduction blockade as CAP amplitude fell to only 18% of initial values. In a separate experiment, treating non-diabetic rats with gangliosides (10 mg/kg/day i.p.) or adding gangliosides (400 micrograms/ml) directly to the medium in which control nerves were maintained during in vitro recording also significantly attenuated the decline in CAP amplitude after 40 min hypoxia, thus effectively inducing a resistance to hypoxic conduction blockade similar to that observed in nerves from diabetic rats. These studies demonstrate that the systemic or acute local administration of gangliosides induces a resistance to hypoxic conduction block in normal nerve and exaggerates the resistance to hypoxic conduction block of diabetic rats.
Calcutt
N A
NA
Department of Pharmacology, School of Basic Medical Sciences, Queen Mary and Westfield College, University of London, UK.
Carrington
A L
AL
Ettlinger
C B
CB
Tomlinson
D R
DR
D000200:Action Potentials / Q000187:drug effects; D000208:Acute Disease; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002417:Cattle; D003921:Diabetes Mellitus, Experimental / Q000150:complications*; D003925:Diabetic Angiopathies / Q000150:complications / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D005732:Gangliosides / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D000860:Hypoxia / Q000150:complications* / Q000503:physiopathology; D007274:Injections, Intraperitoneal; D007511:Ischemia / Q000150:complications / Q000503:physiopathology; D008297:Male; D009431:Neural Conduction / Q000187:drug effects*; D009924:Organ Culture Techniques; D051381:Rats; D011919:Rats, Inbred Strains; D012584:Sciatic Nerve / Q000187:drug effects / Q000503:physiopathology; D013311:Streptozocin
D001786:Blood Glucose; D005732:Gangliosides; D013311:Streptozocin