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PubMed1977

The effects of acute and chronic botulinum toxin treatment on receptor number, receptor distribution and tissue sensitivity in rat diaphragm.

Tritiated alpha-bungarotoxin was used to determine the number and distribution of acetylcholine receptors in innervated, denervated and botulinum toxin-treated muscles. Innervated hemidiaphragms bound approximately 2.3 x 10(11) molecules of alpha-bungarotoxin; binding sites were restricted to the end-plate region. Neither acute denervation nor acute poisoning with botulinum toxin altered the number or distribution of alpha-bungarotoxin binding sites. In chronically denervated hemidiaphragms, there was an increase in alpha-bungarotoxin binding sites (maximum about 5.7 x 10(12); these sites were distributed across the muscle surface. In chronically poisoned hemidiaphragms, there was also an increase in the number (maximum about 4.7 x 10(12)) and distribution of binding sites. Chronic denervation and chronic botulinum toxin treatment both produced supersensitivity to acetylcholine. At maximal sensitivity, the respective ED50 values were: denervated muscle, 1.1 x 10(-6) M; botulinum toxin-treated muscle, 5.0 x 10(-6) M. The combination of denervation plus botulinum toxin treatment did not have additive or synergistic effects on alpha-bungarotoxin binding (4.9 x 10(12) molecules/hemidiaphragm) or on tissue sensitivity to acetylcholine (ED50 = 2.1 x 10(-6) M). It is concluded that denervation and botulinum toxin have rather similar effects on the number and distribution of acetylcholine receptors in rat hemidiaphragm.

Acetylcholine↗
PubMed1976

[Extraction and concentration of Clostridium botulinum toxins from specimens (author's transl)].

In order to detect minimal amounts of Clostridium botulinum toxins in animal tissue or food specimens it is necessary to use an extraction method which results in concentration of the botulinal toxins. In the present examinations, artificially contaminated canned beans were used to develop a suitable procedure for extraction and concentration of botulinal toxins A-E. The procedure consisted of 4 steps: 1. Canned beans were diluted 1:2 with 0.1 m phosphate buffer pH 6.0. 2. The diluted material was homogenised with an "Ultra-Turrax" homogeniser for 20 sec. 3. The monogenised material was centrifuged at 4000 rpm for 30 min. 4. 15 ml of supernatant was concentrated using a "Millipore ultrafiltration chamber" (with a membrane capable of excluding all material with a molecular weight above 25,000). A pressure of 1.5 atmospheres was applied until the terminal volume was 0.5 ml. Following extraction and concentration, the samples were assayed for botulinal toxin in mice. Using this assay the concentration of the five toxins were shown to be as follows: Type A toxin: 19.0-fold toxin concentration Type B toxin: 14.8-fold toxin concentration Type C toxin: 20.6-fold toxin concentration Type D toxin: 28.2-fold toxin concentration Type E toxin: 112.2-fold toxin concentration

Animals↗
PubMed1975

On the question of permeability of the blood-brain barrier to botulinum toxin.

The clinical symptoms of botulinum intoxication suggest that besides the involvement of the peripheral nervous system, the central nervous system is also affected. Studies were undertaken to determine whether pure toxin of Clostridium botulinum type A could be demonstrated in the brains of poisoned mice. With the aid of autoradiography of the toxin marked with 125-I and indirect fluorescent labeling it was possible to show the presence of the toxin in the parenchyma of the brain.

Animals↗
PubMed1977

Intestinal absorption of botulinum toxins of different molecular sizes in rats.

During a period of 10 to 12 h after injection of type B 16S (L) toxin into the ligated duodenum of rats, 0.01 to 0.1% of the total toxicity administered was found in the lymph drawn by cannulation of the thoracic duct. The recovery was 50 to 100 times higher than that of the rat given type B 12S (M) or 7S (S) toxin. During the same period, 0.6 to 1.5% of the specific antigens were recovered, regardless of the molecular size of the toxin that had been administered. In lymph of the B-L or B-M toxin recipient, the toxic and nontoxic components were detected in comparable quantities, indicating that the undissociated progenitor toxin molecule is absorbed through the intestinal wall. Although the toxic component had lost its toxic activity, the two components of B-M toxin appearing in lymph reassembled to reconstruct the 12S molecule, whereas those of B-L toxin did not, although the toxic component was still active. Type B-L, B-M, and B-S toxins showed similar stabilities to in vitro exposure to rat lymph (pH 8.2), but B-L toxin showed a considerably higher stability to intestinal juice (pH 7.0) than did B-M toxin. Thus, the toxicity of lymph of rats administered botulinum toxin intraduodenally depends not upon the rate of absorption, but largely upon the stability in the intestine.

Animals↗
PubMed1979

Antibodies to Clostridium botulinum toxins in free-living birds and mammals.

Naturally-occuring antibodies against Clostridium botulinum toxins were found in Cathartes aura (turkey vultures), Canis latrans (coyotes) and Corvus brachyrhynchos (crows) by the passive hemagglutination (PHA) test and verified by the serum neutralization (SN) test. The prevalence of IHA antibodies was 18 of 20 vultures (90%), 5 of 12 crows (42%) and 25 to 110 coyotes (23%). Vultures and coyotes were seropositive by the PHA test against A, B, C, D, and F toxins. The highest antibody titer 1:8192 was in vulture serum against type C. In descending order, the highest antibody levels were against type C, D, F, E, A and B toxins.

Animal Population Groups↗
PubMed1976

[Morphological and histochemical characteristics of the organism's reaction to administration of Cl botulinum toxin. IV. Cytochemical changes in the cells of the mesencephalic nucleus of trigeminal nerve following administration of Cl. botulinum type B toxin].

After the administration to guinea pigs per os of 1 Dlm of botulin toxin, type B, a change of the RNA synthesis in the nucleoli and DNA depolymerization in the nuclei was observed in some of the cells of the mesencephalic nucleus of the trigeminal nerve. An increase in the activity of succinic dehydrogenase and of acid phosphatase coursed without any necrotic processes in the cells. Basing upon the changes in the activity of succinic dehydrogenase in the neurons of the mesencephalic nucleus a conclusion was drawn that hypoxia began to develop at the period of appearance of paralyses of the limbs and reached its maximum in myasthenia.

Acid Phosphatase↗
PubMed1977

Response of type B and E Botulinum toxins to purified sulfhydryl-dependent protease produced by Clostridium botulinum type F.

A sulfhydryl-dependent protease (SHP) was purified from a culture of Clostridium botulinum type F. The enzyme can activate type E progenitor toxin completely but type B progenitor toxin only partially. This may suggest that SHP by itself could completely activate the toxin of proteolytic C. botulinum types A and F in culture. The toxicity of type E progenitor toxin potentiated by the treatment with SHP persisted, whereas that of derivative toxin decreased rapidly by further incubation with SHP. This may indicate that only the progenitor toxin, the complex of the toxic and nontoxic components, activated by SHP withstands the subsequent exposure to the enzyme in cultures of proteolytic C. botulinum.

Amidohydrolases↗
PubMed1977

Activation of botulinum toxins in the absence of nicking.

The derivative toxins purified from cultures of proteolytic strains of Clostridium botulinum types A and F were found to have been only partially nicked but were fully activated. Trypsinization of C. botulinum type B derivative toxin at pH 6.0 resulted in simultaneous activation and nicking, whereas at pH 4.5, activation preceded nicking. The toxin was split by trypsin at pH 6.0 into two fragments with molecular weights of 112, ooo and 57,000. The toxin contained at least three trypsin-sensitive peptide bonds, one of which was more sensitive than the others at pH 6.0. These results indicate that activation of botulinum toxins by trypsin or endogenous protease (s) is not a direct result of nicking.

Botulinum Toxins↗
PubMed1977

Oral toxicities of Clostridium botulinum toxins in response to molecular size.

Clostridium botulinum type A, B, and F toxins of different molecular sizes were fed to mice to compare the oral toxicities. The progenitor toxin, a complex of a toxic and nontoxic component, of any type was higher in oral toxicity to mice than the dissociated toxic component or the derivative toxin. The former may no doubt play a more important role in the pathogenesis of food-borne botulism. The higher oral toxicity possessed by the progenitor toxin, including the exceptionally high one found with type B-L toxin, can be explained solely by the protection afforded by the nontoxic component attached to the toxic component. The possibility of the highest oral toxicity of type B-L toxin to humans is discussed.

Administration, Oral↗