The effect of diethylcarbamazine on microfilariae ofLitomosoides carinii in vitro and in vivo

Abstract

Culture-derived Litomosoides carinii microfilariae (MFF) were used in in vitro and in vivo systems to investigate the effect of diethylcarbamazine (DEC) on these MFF. In vivo: Male rats, Mastomys natalensis, all of the same age, were injected intrathoracically (12) or intraperitoneally (36) with 10(3) or 10(4) MFF. After 30 min one half of each group of rats was given DEC per os. At 30, 60, and 120 min after DEC administration, two rats from the treated and two from the untreated group were bled and killed. The pleural or peritoneal cavities were rinsed with warm saline (0.15 M NaCl) to recover MFF. In both the intrathoracic and intraperitoneal experiments, equal numbers of MFF were recovered from treated and control rats at 30 and 120 min. However, at 60 min 85.5% fewer were recovered from the treated than from the nontreated animals. MFF were not found in the blood. In vitro: MFF were added to tissue culture dish wells (Linbro Div., Flow Labs, Hamden, Conn) prepared as follows: DEC-Serum (serum from normal rats given DEC at 500 mg/kg), DEC + Serum (serum with added DEC), serum only, RPMI 1640 only, and RPMI 1640 + DEC. Furthermore, the five treatments were prepared either with or without unstimulated peritoneal exudate (PE) cells. At 30 min in the DEC-Serum wells 45% of the MFF had adherent PE cells; in the remaining wells these cells adhered to 11% or fewer MFF. We interpret the aforementioned phenomena as representing the first step in the trapping and elimination of MFF after DEC treatment of L. carinii-infected M. natalensis.

Diethylcarbamazine (DEC): immunopharmacological interactions of an anti-filarial drug

“…Clearly, in comparing different systems a variance of outcomes of this nature often occurs. Weiner, Abraham & D'Antonio (1986) reported that adhesion of M. natalensis peritoneal exudate cells to Mf in vitro was enhanced fourfold on addition of serum from normal rats which had received DEC in vivo. No effect was seen on adding DEC directly to the in vitro assay, whether alone or in conjunction with normal serum.…”

Automated Imaging and other developments in whole‐organism anthelmintic screening

“…Where appropriate laboratory models of human parasite species are unavailable or unable to generate sufficient material, closely related animal parasite species have been used as alternatives For example, in drug discovery against filarial species a multitude of animal infections such as Acanthocheilonema viteae, Litomosoides carinii, Onchocerca lienalis and O. gutturosa have been employed . Recent success demonstrating this has come with the evaluation of O. gutturosa and O. lienalis for screening antibiotics for anti‐ Wolbachia /filarial activity .…”