ABSTRACT. Duchenne muscular dystrophy (DMD) is a human disease characterized by progressive and irreversible skeletal muscle degeneration caused by mutations in genes coding for important muscle proteins. Unfortunately, there is no efficient treatment for this disease; it causes progressive loss of motor and muscular ability until death. The canine model (golden retriever muscular dystrophy) is similar to DMD, showing similar clinical signs. Fifteen dogs were followed from birth and closely observed for clinical signs. Dogs had their disease status confirmed by polymerase chain reaction analysis and genotyping. Clinical observations of musculoskeletal, morphological, gastrointestinal, respiratory, cardiovascular, and renal features allowed us to identify three distinguishable phenotypes in dystrophic dogs: mild (grade I), moderate (grade II) and severe (grade III). These three groups showed no difference in dystrophic alterations of muscle morphology and creatine kinase levels. This information will be useful for therapeutic trials, because DMD also shows significant, inter-and intra-familiar clinical variability. Additionally, being aware of phenotypic differences in this animal model is essential for correct interpretation and understanding of results obtained in pre-clinical trials.

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Ultrasonography is an excellent method for investigation of animals with gastrointestinal disorders, and is particularly useful for excluding obstructive processes.

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Tonic immobility (TI) is a response to fear or threat by remaining motionless, principally when attacked by predators from which there is no possibility of escape. Thus, here we demonstrate a way of easily reproducing this phenomenon in a laboratory setting and characterize the cardiac electromechanical alterations during TI. We observed a significant decrease in heart rate (HR) and changes of rhythm in electrocardiogram during TI in rabbits. Echocardiogram showed a significant increase in the left ventricle chamber diameter during systole and a consequent decrease in fractional shortening and ejection fraction, in addition to the HR and rhythm changes. There was also a significant decrease in aortic and pulmonary artery blood flow. Diastolic functional changes included a significant decrease of the peak atrial contraction velocity (A peak) and consequent increase in the ratio of peak early diastolic velocity to A peak and increased isovolumetric relaxation time. We were able to prove that TI changes the cardiac function considerably. Although the "fight-or-flight" response is the most common response to fear, which is characterized by the action of sympathetic nervous system with tachycardia and increased physical activity, TI is an alternative anti-predator behavior causing cardiac changes opposite to the "fight-or-flight" phenomenon.

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Approved by the following research ethics committee: Universidade Federal do Paraná, protocol #011/2011. ABSTRACTPurpose: The aim of this study was to investigate the effects of prostaglandin analogs on blood flow in the ophthalmic artery of clinically healthy rabbits. Methods: Fifty-five clinically healthy New Zealand white rabbits were divided into six groups, and the left eyes were treated for four weeks with the preservative benzalkonium chloride (BAK) only or a topical formulation of different prostaglandin analogs (bimatoprost BAK, tafluprost BAK-free, travoprost BAK, travoprost POLYQUAD, and latanoprost BAK). Color Doppler imaging was performed before and after the treatments. The mean values of the peak systolic velocity (PSV) and end diastolic velocity and the resistive index (RI) were calculated. Statistical analysis was performed to compare the differences pre-and post-treatment for each drug and post-treatment among the drugs. Results: The prostaglandin analogs did not affect PSV. Bimatoprost BAK, travoprost POLYQUAD, and latanoprost BAK did not change RI. Tafluprost BAK-free and travoprost BAK therapy resulted in similar reductions in RI. No significant differences pre-and post-treatment were found when BAK was administered alone. Conclusion:The prostaglandin analogs tafluprost BAK-free and travoprost BAK improved blood flow in the ophthalmic artery in healthy New Zealand white rabbits, which suggests that these drugs enhance the prevention of the progression the progression of glaucoma. Keywords