Avaliação do plasma sanguíneo de éguas em diferentes fases reprodutivas pela técnica de biospeckle

Abstract

This study aimed to evaluate the applicability of the biospeckle laser techniques as a tool to analyze the biological activity in blood plasma samples from mares in different reproductive stages. For this purpose, samples were collected from 40 pregnant Mangalarga Machador mares from the Formoso 2S horse farm in Cajueiro – AL. The mares were classified into 4 groups of 10 animals each according to the pregnancy stage: 10 empty mares (not pregnant), 10 pregnant mares in the early third of pregnancy between 1 and 4 months, 10 pregnant mares in the final third of the pregnancy between 7 and 11 months, and 10 lactating mares (within the two months post-partum). The biospeckle patterns were obtained using a CCD camera to capture images of the reflection of a laser shone into blood serum samples from mares in different reproductive stages. These patterns were analysed using image processing techniques through the computational application STMD, applying THSP (time history speckle pattern) methodology which evaluates the temporal evolution of the interference image generated on the surface of the sample over time. A coherence matrix generated from the THSP was used to present the intensity dispersion module which provided the bioactivity data. This data was then processed using the program OriginPro 8.Ink, generating graphs and comparing the results from the different groups under study. A general biospeckle signature was observed regardless of the mares’ reproductive stage considered in this study. A short peak of movement of the samples associated to the placement of the drop on the slide was observed. It was followed by an ascending curve starting between 5 and 10 minutes of observation and reaching a peak within 15 and 25 minutes and finally decayed uniformly until almost zero after 45 minutes. The group of pregnant mares in the final third of pregnancy presented superior bioactivity when compared to pregnant mares in the early third of pregnancy. The curve observed for the group of lactating mares is similar to the curve obtained for the group of pregnant mares in the early third of pregnancy. Bioactive molecules act as dispersion elements of coherent light incident on a sample. The variability in dispersive elements in the different reproductive stages influenced the biospeckle pattern detected for each stage. It was concluded that samples from reproductive stages with lower variation/concentration of bioactive substance presented lager scattering, which generates more mobility and dispersion in the blood plasma detected in the dynamic speckle analysis.