[Identification of a neutral protease in the intestine of Boophilus microplus with electrophoresis in polyacrylamide gels copolymerized with gelatin]. / Identificación de una proteasa neutra en intestino de Boophilus microplus por electroforesis en geles de poliacrilamida copolimerizados con gelatina.

A neutral activity of Boophilus microplus in the intestine was identified by electrophoresis in polyacrilamide gel copolymerized with gelatin. The maximum of activity was attained at pH 6.0. The highest specific activity at that pH was obtained with casein substrate. The disappearance of this activity was observed in both substrates after the addition of phenylmethylsulphonyl fluoride in the reaction mixtures. It was very interesting to find out an endopeptidase activity with these characteristics in the intestine, in spite of the fact that the digestive activity in ticks is intracellular at very acid pH, which does not occur in other insects.

[Effect of digestion on the immunoglobulin G concentration in the intestinal contents of replete Boophilus microplus females]. / Efecto de la digestión en la concentración de inmnuglobulina G en la ingesta de hembras de Boophilus microplus repletas.

In the present paper it was determined the concentration of immunoglobulin G in extracts from gut of female Boophilus microplus engorded during the first 7 days of the second stage of continual digestion by using the simple radial immunodiffusion technique. It was also measured the concentration of hemoglobin by spectrophotometric methods. The analysis of correlation between both variables made during the study was positive and significant for p < 0.05. The analysis of simple variance and the application of Duncan's test resulted in a marked reduction of the concentrations of hemoglobin in the gut from the 5th day of study, which is connected with the beginning of the active process of oviposition, and in an important decrease of the concentration of immunoglobulin from the 7th day of the study. Though there is a trend to diminish in the concentrations of both blood proteins, the proteolysis of the IgG by gut extracts could not be produced in vitro.