The antioxidants dimethylsulfoxide and dimethylthiourea affect the immediate adhesion responses of larval haemocytes from 3 lepidopteran insect species.
Antioxidants, dimethylsulfoxide (DMSO) and dimethylthiourea (DMTU), at concentrations not affecting the viability of blood cells (haemocytes) from the larval stage of 3 lepidopteran insects - Galleria mellonella, Lymantria dispar, and Malacosoma disstria - differed in their influence on the innate binding of haemocytes to glass, bacteria to haemocytes, and on humoral responses to alien materials. In vitro DMSO had little effect, whereas DMTU substantially impaired the adhesion of the haemocyte types, the plasmatocytes and granular cells, to slides as well as the attachment of Bacillus subtilis to these haemocytes. Although both antioxidants increased lysozyme and phenoloxidase activities, there was no correlation of enzyme activity and haemocyte adhesion responses, possibly reflecting sequestered radicals. Nitric oxide and hydroxyl radicals offset the DMTU effect. In the absence of antioxidants, inactivate protein kinases A (PKA) and C (PKC) enhanced haemocyte aggregation. In general, DMSO, as opposed to DMTU, did not alter the effects of PKA and PKC activators and inhibitors on haemocyte aggregation or of PKC and PKA activities. High concentrations of DMSO and all levels of DMTU, although inhibiting PKA and PKC, inhibited haemocyte adhesion to slides. Comparable results occurred for DMTU-treated haemocytes incubated with B. subtilis. In vivo DMSO, unlike DMTU, did not impair plasmatocyte or granular cell responses to foreign materials, including bacterial removal from the haemolymph and nodulation.
Dunphy
Gary B
GB
Department of Natural Resource Sciences, Macdonald Campus, McGill University, Macdonald Campus, 21111 Lakeshore Road, Sainte Anne de Bellevue, QC H9X 3V9, Canada. dunphy@mcgill.ca
Chen
Genhui
G
Webster
John M
JM
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001412:Bacillus subtilis / Q000502:physiology; D002448:Cell Adhesion / Q000187:drug effects; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D005898:Glass; D006434:Hemocytes / Q000187:drug effects* / Q000276:immunology* / Q000382:microbiology; D007814:Larva / Q000187:drug effects / Q000201:enzymology / Q000276:immunology; D007915:Lepidoptera / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology* / Q000382:microbiology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D013890:Thiourea / Q000031:analogs & derivatives* / Q000494:pharmacology
D000975:Antioxidants; C038983:1,3-dimethylthiourea; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D013890:Thiourea; D004121:Dimethyl Sulfoxide