Decreased Prolidase Activity in Patients with Posttraumatic Stress Disorder

OBJECTIVE: Many neurochemical systems have been implicated in the development of Posttraumatic Stress Disorder (PTSD). The prolidase enzyme is a cytosolic exopeptidase that detaches proline or hydroxyproline from the carboxyl terminal position of dipeptides. Prolidase has important biological effects, and to date, its role in the etiology of PTSD has not been studied. In the present study, we aimed to evaluate prolidase activity in patients with PTSD. METHODS: The study group consisted of patients who were diagnosed with PTSD after the earthquake that occurred in the province of Van in Turkey in 2011 (n=25); the first control group consisted of patients who experienced the earthquake but did not show PTSD symptoms (n=26) and the second control group consisted of patients who have never been exposed to a traumatic event (n=25). Prolidase activities in the patients and the control groups were determined by the ELISA method using commercial kits. RESULTS: Prolidase activity in the patient group was significantly lower when compared to the control groups. Prolidase activity was also significantly lower in the traumatized healthy subjects compared to the other healthy group (p<0.01). CONCLUSION: The findings of the present study suggest that the decrease in prolidase activity may have neuroprotective effects in patients with PTSD.

Are levels of digestive enzyme activity related to the natural diet in passerine birds?

Digestive capabilities, such as the rates nutrient hydrolysis and absorption, may affect energy intake and ultimately feeding behavior. In birds, a high diversity in gut biochemical capabilities seems to support the existence of a correlation between the morphology and physiology of the intestinal tract and chemical features of the natural diet. However, studies correlating the activity of digestive enzymes and the feeding habits at an evolutionary scale are scarce. We investigated the effect of dietary habits on the digestive physiological characteristics of eight species of passerine birds from Central Chile. The Order Passeriformes is a speciose group with a broad dietary spectrum that includes omnivorous, granivorous and insectivorous species. We measured the activity of three enzymes: maltase, sucrase and aminopeptidase-N. Using an autocorrelation analysis to remove the phylogenetic effect, we found that dietary habits had no effect on enzymatic activity. However, we found that granivorous and omnivorous species had higher levels of disaccharidase activities and insectivores had the lowest. The major difference in enzymatic activity found at the inter-specific level, compared to the reported lower magnitude of enzyme modulation owing to dietary acclimation, suggests that these differences to some extent have a genetic basis. However, the lack of a clear association between diet categories and gut physiology suggested us that dietary categorizations do not always reflect the chemical composition of the ingested food.

Angiotensin-Converting Enzyme 1/D polymorphism in Behcet's disease

To investigate a potential relationship between I/D polymorphism within intron 16 of the angiotensin-converting enzyme [ACE] gene located on human chromosome 17 and Behcet's disease. Materials and Genomic DNA was obtained from 35 Turkish patients diagnosed with Behcet's disease according to the International Study Group criteria and 150 healthy individuals. Polymerase chain reaction was used to detect the presence of I and D [insertion and deletion] alleles in intron 16 of the ACE gene in these DNA samples. We found differences in ACE I/D polymorphism between Behcet's disease and healthy controls [x2 = 4.61, d.f. = 1, p = 0.044]. In Behcet's disease patients, the D allele frequency was 84.3% and I allele frequency 15.7%. An association between Behcet's disease and ACE polymorphism may provide a useful basis for future molecular studies and therapeutic approaches in this complex disease