Salivation pattern of Rhodnius prolixus (Reduviidae; Triatominae) in mouse skin

• Published in: Journal of insect physiology Vol. 52; no. 5; pp. 468 - 472
• Main Authors: Soares, Adriana Coelho, Carvalho-Tavares, Juliana, Gontijo, Nelder de Figueiredo, dos Santos, Vânia Cristina, Teixeira, Mauro Martins, Pereira, Marcos Horácio
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2006
• Subjects: acridine orange; Animals; engorgement; fluorescein; Fluorescent Dyes; fluorescent labeling; hematophagy; Hemolymph - metabolism; Hydrogen-Ion Concentration; Intravital microscopy; labeling techniques; Mammal host; Mice; Reduviidae; Rhodnius - physiology; Rhodnius prolixus; Saliva; Saliva - metabolism; Salivary Glands - physiology; Salivation; Salivation - physiology; skin; Skin - parasitology; Triatoma infestans; Triatomine; Intravital microscopy; Rhodnius prolixus; Mammal host; Saliva; Salivation; Triatomine
• ISSN: 0022-1910; 1879-1611
• DOI: 10.1016/j.jinsphys.2006.01.003

The objective of this work was to study the pattern of salivation of triatomines during feeding in mouse skin. Rhodnius prolixus was fed with a solution of the dye acridine orange or fluorescein. The saliva was efficiently labelled with acridine orange, probably due to the difference in pH between the salivary gland (⩽6.0) and the hemolymph (6.5–7.0). This procedure was not effective at labelling the saliva of Triatoma infestans, however, fluorescent labelling of R. prolixus saliva allowed us to demonstrate that salivation occurs during entire feeding process. The saliva is released soon after the bite. In the probing phase, saliva is pumped continuously in the host skin, including around the blood vessels. During the engorgement phase, saliva is observed in a bolus within the blood vessel and some of it is sucked up by the insect, together with blood. The frequency of saliva emission inside the vessels was low (0.51±0.18 Hz). The saliva deposition in the microcirculation is continuous and modulated by the frequency of the cibarial pump because, when functioning at high frequency, cibarial pump sucks almost all saliva to the insect gut. This mechanism would determine the quantity of saliva deposited in the microcirculation as necessary, and consequently minimizing the host's immune response to salivary antigens.