cyclic-gmp and Neuromuscular-Diseases

This study tested the hypothesis that a single hindlimb burn has both local and distant effects. Male CF1 anaesthetized mice were given a full thickness scald burn of 3 per cent total body surface area (BSA) by immersion of their left hindlimb in water at 95 degrees C for 5 s. Muscle tension was measured through twitch analysis. Levels of cyclic adenosine 3'-5' monophosphate (cAMP) and cyclic guanosine 3'-5' monophosphate (cGMP) were analysed by 125I-radioimmunoassay. Measurements were made in gastrocnemei of the ipsilateral burned and contralateral unburned limbs over a 28-day postburn period. Within 1 week the burned limb showed an increase in both tension and a 100-fold increase in levels of cAMP. However, by the end of the second week muscle tension in the burned limb dropped to one-seventh of control values despite persistence of high levels of cAMP. In contrast, the systemic effects were manifested in the unburned contralateral limb which showed tension to undergo a six-fold compensatory increase at the end of the second week with a 75-fold increase in cAMP. By the end of 4 weeks, tension levels of both burned and unburned limbs were attenuated to one-half control values indicating neuromuscular (NM) dysfunction. Nevertheless, cAMP levels remained elevated in both limbs. Levels of cGMP were reduced throughout the 4-week postburn period. Subsequent to the single hindlimb injury both ipsilateral and contralateral gastrocnemei muscles showed elevated levels of total protein content.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Burns; Cyclic AMP; Cyclic GMP; Disease Models, Animal; Hindlimb; Male; Mice; Mice, Inbred Strains; Muscle Proteins; Muscles; Neuromuscular Diseases; Nucleotides, Cyclic

Of the secondary messengers, cyclic quanosine monophosphate, but not cyclic adenosine monophosphate, was reduced by 80% in the cervical spinal cord and by 56% in the cerebellum of clinically affected homozygote "wobbler" mice compared to sex- and age-matched litter-mate clinically unaffected control mice. A neurotransmitter, gamma aminobutyric acid, and high-energy intermediates, adenosine triphosphate and phosphocreatine, were not significantly different in affected or unaffected mice.

Topics: Animals; Brain Chemistry; Cyclic AMP; Cyclic GMP; Disease Models, Animal; gamma-Aminobutyric Acid; Mice; Motor Neurons; Mutation; Neuromuscular Diseases; Spinal Cord

Topics: Adolescent; Adult; Age Factors; Aged; Amyotrophic Lateral Sclerosis; Bulbar Palsy, Progressive; Cyclic AMP; Cyclic GMP; Female; Glucagon; Humans; Male; Middle Aged; Muscular Atrophy; Muscular Dystrophies; Myositis; Neuromuscular Diseases; Nucleotides, Cyclic; Radioimmunoassay