The effect of homogenates and excretory/secretory products ofNippostrongylus brasiliensisand of acetylcholinesterase on the amplitude and frequency of contraction of uninfected rat intestinein vitro

Abstract

SUMMARYWhole worm homogenates and excretory/secretory (E/S) products of adultNippostrongylus brasiliensissignificantly decreased the amplitude of contractions of segments of uninfected rat intestine maintained in an organ bath, with significantly larger volumes of E/S products being required to bring about a similar decrease to that caused by the whole worm homogenate. Boiled samples of homogenate and E/S products significantly decreased the amplitude of contractions of uninfected rat intestine, but larger volumes were needed than with unboiled samples. Frequency of contraction was unaltered by homogenates or E/S products. When electric eel AChE was injected into the lumen of segments of uninfected rat intestine maintained in an organ bath there was no significant decrease in the amplitude of contractions. These results suggest that substances present in the E/S products ofN. brasiliensissignificantly reduce the amplitude of contractions of uninfected rat intestinein vitroand that the biochemical holdfast responsible for this phenomenon may not be AChE.