JP2539619B2 - Muscular dystrophiosis drug - Google Patents

Description

TECHNICAL FIELD The present invention relates to a therapeutic agent for muscular dystrophy.

[Prior Art and Its Deficiencies] Muscular dystrophy is a hereditary, primary disorder of skeletal muscle, and is a disease mainly characterized by progressive muscle weakness and degeneration of muscle tissue. In 1954, Watt et al. Proposed a classification that emphasized heredity, and the concept of disease was almost established. However, the etiology is still unknown at this time.

As a treatment for muscular dystrophy, experimental treatment with various drugs has been conventionally performed. For example, penicillamine, allopurinol, nucleotides, adrenocortical hormones and the like have been tested for treatment, but none have been confirmed to be effective until this time, and a root cure for muscular dystrophy is not known.

[Problems to be Solved by the Invention] The present invention is to provide a therapeutic agent for muscular dystrophy which could not be produced conventionally.

[Means for Solving the Problems] That is, the present invention provides a therapeutic agent for muscular dystrophy containing cholera toxins as an active ingredient.

Effect of the Invention According to the present invention, a therapeutic agent for muscular dystrophy having an excellent therapeutic effect can be obtained.

[Detailed Description of the Invention] Cholera toxin, which is a typical example of the active ingredient of the therapeutic agent for muscular dystrophy of the present invention, has a molecular weight of about 84,000 and a subunit A1 having a molecular weight of about 27,000 and a subunit B5 having a molecular weight of about 11600. It is a protein and the amino acid sequences of these subunits have been deduced based on the sequence of the cloned DNA (see JJ Mekalanos et al. Nature (Nature 306 pp.551-557 (1983)).
This substance is a gram-negative bacterium Vibrio cholerae.
However, the cholera toxin used in the present invention is not necessarily limited to that produced by this bacterium, and is produced by other microorganisms or cultured cells by genetic engineering means in accordance with ordinary methods, for example. May be In general, for a protein having physiological activity, the structure showing the physiological activity is not specified in a single manner, and it is understood by those skilled in the art that a range of structural differences is allowed in order to exhibit substantially the same physiological activity. It is widely recognized. Therefore, the cholera toxins as the active ingredient of the therapeutic agent for muscular dystrophy of the present invention include, in addition to the above-mentioned cholera toxin, those in which the structure of Escherichia coli enterotoxin or the cholera toxin is partially modified, for example, some amino acids are It also includes a protein in which a part of amino acids are removed or a part of amino acids are added, which has a therapeutic effect on muscular dystrophy equivalent to that of the toxin.

The route of administration is preferably a parenteral route, for example, intravenous injection, intraperitoneal injection, intramuscular injection, subcutaneous injection and the like. The single dose varies depending on the degree of muscular dystrophy, the condition of the patient, etc., and is appropriately determined by the judgment of the doctor for each clinical case, but usually 0.5 μg / kg to 50
It is μg / kg. Similarly, the number of administrations and the administration period are appropriately determined by the judgment of the doctor.

The toxicity of cholera toxin to mammals is, for example, LD ₅₀ of 5 μg / mouse in mice.

The therapeutic agent for muscular dystrophy of the present invention may be a cholera toxin preparation itself, or an excipient commonly used in parenteral medicine, such as a diluent, a buffer, an osmotic pressure adjusting agent, and a stabilizing agent. It may be a mixture with a preservative or the like. For example, a mixture of physiological saline or a phosphate buffer solution with cholera toxins at a concentration of 0.1 to 2.0 mg / ml is used as an injection.

Next, the effects of the therapeutic agent for muscular dystrophy of the present invention will be specifically described with reference to Examples.

[Example] In this example, C57BL / 6J-dy strain mice were used. C57BL
/ 6J-dy strain mice have autosomal recessive gene dy (dystrophiamuscularis) with congenic lines having C57BL / 6J as a genetic background. The homozygous animals weigh less than at birth, and ataxia, skeletal muscle atrophy, and paralysis of the extremities (particularly strong in the hind limbs) appeared at about 3 weeks of age, and symptoms gradually progressed, and most of them were due to respiratory failure within 6 months. Mice die. Since muscular dystrophy mice exhibit so-called necrotizing myopathy whose expression symptoms in skeletal muscle are similar to those of human Duchenne-type or Becker-type progressive muscular dystrophy, conventionally, it is preferable to treat these diseases. It is considered to be a simple animal model and is used in many experiments.

(1) Cholera toxin and its administration method The cholera toxin used in the experiment was separated and purified from cholera.

The administration method was as follows: 0.1 ml of a phosphate buffer containing 0.5 μg of cholera toxin was injected into the test mouse, a 60-day-old male dy homo mouse, by tail vein injection. In the test, mice 10 days after injection were used.

(2) Device and method for endurance test of limb muscle The endurance test device used in the experiment is a cylindrical wire mesh basket with a ceiling placed on a hot plate heated to 60 ° C.

The test method is to put a test maus in a wire cage,
Since the soles of the feet are hot, he tries to climb up on the wire mesh, but if the muscles have poor durability, they fall onto the hot plate. Therefore, of the measurement time of 7 minutes, the time during which the extremities were completely separated from the hot plate and clung to the wire net was measured.

(3) Results The results are shown in the figure. In the figure, N is a normal control mouse (5 animals average), E _{1 to} E ₄ are cholera toxin-administered dy mice, and C _{1 to} C ₄ are non-administered dy mice. As is clear from the figure, in all 5 normal mice, once they climbed the wire net, they did not fall for more than 7 minutes, whereas in the non-administered dy mice, the average endurance time of 5 cases was 5 times. It is about 2 minutes, and it can be seen that it fell on the hot plate for about 2/3 of the measurement time. On the other hand, cholera toxin-administered mice may fall, but they also have the ability to climb again immediately, and endurance is almost equal to that of normal mice within the measurement time, while cholera toxin-administered mice are similar to non-administered dy mice. Movement disorders such as convulsive seizures or dragging of the hind limbs disappeared at all. From this, it is understood that the therapeutic agent for muscular dystrophy of the present invention has an excellent therapeutic effect.

[Brief description of drawings]

The drawing shows dy administered with the therapeutic agent for muscular dystrophy of the present invention.
It is a figure which shows the result of the endurance test about a mouse | mouth, a normal control mouse, and a non-administration dy mouse.

Claims (1)

(57) [Claims] 1. A therapeutic agent for muscular dystrophy comprising cholera toxins as an active ingredient.