Characterization of Brown spider (Loxosceles intermedia) hemolymph: Cellular and biochemical analyses

Abstract

This is the first study on the hemolymph from a spider of the Loxosceles genus. These animals are responsible for a great number of envenomation cases worldwide. Several studies on Loxosceles venoms have been published, and the knowledge about the venom and its toxins is considerable, not only regarding the biological and biochemical characterization, but also regarding structural, genetic and phylogenetic approaches. However, the literature on Loxosceles hemolymph is nonexistent. The main goal of the present study was to characterize biochemically the hemolymph content, and especially, to identify its different hemocytes. Moreover, many papers have already shown molecules whose source is the hemolymph and their very interesting activities and biomedical applications, for example, antifungal and antibacterial activities. A 2D-SDS-PAGE of brown spider hemolymph showed approximately 111 spots for pH 3-10 and 150 spots for pH 4-7. A lectin-blotting assay showed that hemolymph carbohydrate residues were similar to those found in venom. Several types of TAG and DAG phospholipids were found in the hemolymph and characterized by HPTLC and mass spectrometry. Four different hemocytes were characterized in Loxosceles intermedia hemolymph: prohemocyte, plasmatocyte, granulocyte and adipohemocyte. This paper opens new possibilities on toxinology, studying an unknown biological material, and it characterizes a source of molecules with putative biotechnological applications.

Hemolymph cytology, hemocyte count, glucose, and electrolyte reference intervals in 93 Cameroon red tarantulas (Hysterocrates gigas)

“…The appearance of plasmatocytes seems fairly similar across spider species . However, differences exist.…”

“…Anticoagulants commonly used for hematology in domestic species such as lithium heparin, sodium citrate, and EDTA are reportedly inefficient in preventing coagulation in invertebrates, consistent with our findings when lithium heparin was used in the present study. Various solutions have been reported effective in preventing the coagulation of arachnid hemolymph, but these solutions are not readily available for clinicians. Therefore, the simpler technique of rapid hemolymph cooling was investigated, which sufficiently slowed coagulation to permit immediate analysis.…”

“…Hemocytes of other arachnid species have been described, but there is no consensus on nomenclature . Most publications describe prohemocytes as small round cells with a high nucleus‐to‐cytoplasm ratio, as observed in the CRT . Differentiation between prohemocytes and plasmatocytes was challenging, and identification was mainly based on the round shape and absence of intracytoplasmic granules within the former.…”

“…As spiders have a semi‐open vascular system, arteries direct hemolymph to organs and appendages, while pressure gradients direct hemolymph back to the heart through an open venous system . Hemolymph is composed of electrolytes, proteins, nutrients, hemocytes, and hemocyanin, the copper‐based oxygen‐carrying and storage pigment responsible for the pale blue appearance of hemolymph . The main sites of hemocytopoiesis are within the inner wall and adventitia of the heart, where prohemocytes are released into the hemolymph .…”

“…A few studies have evaluated the biochemical composition and osmolality of the hemolymph of theraphosid spiders, and other studies have described the morphology and function of hemocytes in various spider species . However, publications reporting reference values for total and differential hemocyte counts are lacking.…”