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Decrease in DEET repellency caused by nitric oxide in Rhodnius prolixus.

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Archives of Insect Biochemistry and Physiology 67:1–8 (2008)
Decrease in DEET Repellency Caused by Nitric Oxide
in Rhodnius prolixus
Valeria Sfara,1* Eduardo N. Zerba,1,2 and Raúl A. Alzogaray1,2
N,N-diethyl-3-methylbenzamide (DEET) is widely used as an insect repellent; however, little is known about its mode of
action. On the other hand, nitric oxide (NO) participates in the olfaction transduction pathway of insects. In this work, nitrosoacetyl-cysteine (SNAC), a nitric oxide donor, or dibutyril-cyclic-GMP (db-cGMP), the cyclic nucleotide analog, were applied on
fifth instar nymphs of Rhodnius prolixus before exposing them to DEET, to obtain information about the possible role of NO/
cGMP system in the olfaction process. In the first place, we exposed the nymphs to several DEET concentrations (70, 700,
1,750, and 3,500 µg/cm2). All these concentrations produced a repellent effect. A decrease in repellency during the course of
the experiment was observed when the nymphs were exposed to high concentrations of DEET (700 and 1,750 µg/cm2),
suggesting an adaptation phenomenon. The pre-treatment of the insects with 15 µg /insect of SNAC or 2 µg/insect of dbcGMP produced a reduction of the repellency. An increase in locomotor activity was observed in insects exposed to 350 or 700
µg/cm2 DEET. Although exposure to 70 µg/cm2 DEET produced a high repellency response, it did not modify the insects’
locomotor activity. Insects treated with two doses of SNAC before being exposed to 350 µg/cm2 of DEET showed no differences
in locomotor activity compared to controls. Arch. Insect Biochem. Physiol. 67:1–8, 2008. © 2007 Wiley-Liss, Inc.
KEYWORDS: nitric oxide; olfaction; repellency; DEET; Rhodnius prolixus
INTRODUCTION
An insect repellent has been defined as “a
chemical which causes insects to make orientated
movements away from its source” (Dethier et al.,
1960). Other authors state that an insect repellent
is “a chemical or mixture of chemicals that, acting
in the vapour phase, causes the insects to behave
in ways which result in its movements away from
the source of the material” (Barton Browne, 1977).
N, N- diethyl-3-methylbenzamide (DEET) is the
active ingredient of most insect repellent products
in the market (Reeder et al., 2001). Its effectiveness has been shown against a number of haemato-
phagous insects, including the triatomine Rhodnius
prolixus (Buescher et al., 1985), the major vector
of Chagas disease in Central America and north of
South America (Schofield, 1994).
DEET has also shown a repellent effect in Triatoma infestans, (Alzogaray et al., 2000; Sfara et al.,
2006). In these studies, it was observed that pretreatment of T. infestans nymphs with the sulphydryl reagent N-ethylmaleimide (NEM), decreased
the repellent effect of DEET (Alzogaray et al.,
2000). The inhibition of DEET repellency in T.
infestans by NEM pre-treatment was attributed to
chemoreception blockage. An earlier work of our
laboratory demonstrated the capacity of NEM to
1
Centro de Investigaciones de Plagas e Insecticidas (CIPEIN-CITEFA/CONICET), (B1603ALO) Villa Martelli, Prov. de Buenos Aires, Argentina
2
Universidad Nacional de General San Martín, (B1650CDL) San Martín, Prov. de Buenos Aires, Argentina
Contract grant sponsor: Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET).
Abbreviations used: db-cGMP = dibutiryl-cyclic-guanosine-monophosphate; DEET = N,N-diethyl-3-methylbenzamide; NO = nitric oxide;
SNAC = nitroso-acetyl-cysteine; RC = repellency coefficient.
*Correspondence to: Lic. Valeria Sfara, CIPEIN-CITEFA, JB de La Salle 4397, (B1603ALO) Villa Martelli, Prov. de Buenos Aires, Argentina.
E-mail: vsfara@citefa.gov.ar
Received 13 November 2006; Accepted 19 May 2007
© 2007 Wiley-Liss, Inc.
DOI: 10.1002/arch.20210
Published online in Wiley InterScience (www.interscience.wiley.com)
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Sfara et al.
interfere with T. infestans feeding and mating; this
was also attributed to the blockage of chemoreception, particularly olfaction (Picollo et al., 1993).
Klun et al. (2006) proved that DEET exerted an
olfactory-based repellent effect on Aedes aegypti,
Anopheles stephensi, and Phlebotomus papatasi.
Nitric oxide (NO), an ubiquitous gaseous molecule present in most cell types, participates in the
olfaction transduction pathway of insects (Bicker,
1998; Davies, 2000). The main function of this
membrane-permeating molecule is the activation
of soluble guanylyl cyclase, leading to the formation of cyclic GMP (cGMP) in target cells (Müller,
1997). Neurochemical investigations of NO/cGMP
signalling in the nervous system of insects suggest
it has critical functions in olfaction, vision, and
mechanosensation (Bicker, 2001). Olfactory receptor cells respond to odorant stimulation with depolarization of the cell membrane. There is an
underlying mechanism of transduction that converts the electrical signal into a chemical one, generally mediated by cyclic nucleotides such as cGMP,
cAMP, and IP3 (Breer et al., 1992).
S-nitrosothiols are nitric oxide donors that release NO, mimicking the effect of endogenous NO.
During the last few years, special attention has been
paid to S-nitrosothiols due to their important role
in NO transport and storage in a wide range of
physiological processes, including those mediated
by the NO/cGMP system (Hogg, 2002; Ng and
Kubes, 2003; Al-Saldoni and Ferro, 2004).
The aim of this work was to obtain information about the possible role of the NO/cGMP system in the olfaction mechanisms underlying DEET
repellency in R. prolixus.
Chemicals
N, N-diethyl-3-methylbenzamide (DEET) with
97% purity was purchased from Aldrich (Milwaukee, WI); acetone, analytical grade, was purchased
from Merck (Darmstadt, Germany); db-cGMP was
purchased from Sigma-Aldrich (Milwaukee, WI).
Nitroso-acetyl-cysteine (SNAC) was synthesized
in our laboratory by acid-catalyzed nitrosation of
acetyl-L-cysteine as previously described (Mathews
and Kerr, 1993). Briefly, 32.6 mg of N-acetyl- Lcysteine was weighed in a vial of 4 ml and dissolved in 250 µl of distilled water (Solution A).
Similarly, 46 mg of NO2Na were dissolved in 500
µl of a 0.1% EDTA solution (Solution B). Then,
150 µl of Solution B was gently added to Solution
A. These compounds react immediately, and the
resulting solution becomes red. This red solution
was acidified to pH = 2 by adding HCl 1N and
then left to stand at room temperature for 5 min.
The solution was then neutralized with NaOH 0.5
N and taken to a final volume of 5 ml with cold
acetone, obtaining a 40 mM solution of SNAC in
acetone. This solution was finally diluted 1:10 with
acetone to obtain a 4-mM solution of SNAC. Both
solutions were deaerated with argon. SNAC was prepared daily and the diluted stock solution was kept
in the dark at –15°C until use. Synthesis by this
method produces S-nitroso-N-acetylcysteine, that is
>99% pure and stable at pH <3.0 (Byler et al.,
1983). The exact final concentration of SNAC was
determined using a spectrophotometer (Shimadzu
UV-160) at 330 nm, based on the molar extinction
coefficient of 727 (Mathews and Kerr, 1993).
Recording Equipment
MATERIALS AND METHODS
Biological Material
Fifth instar nymphs of Rhodnius prolixus, obtained from a susceptible strain kept in our laboratory since 1975, were used for bioassays. Insects
were starved for a period of 15–25 days after emergence and kept in a temperature-controlled chamber at 28°C, under a 12:12 h (L:D) photoperiod.
A closed-circuit black-and-white video camera
(VC 1910, Sanyo Electrical Co., Tokio, Japan) was
placed 15 cm above the centre of the test arena.
An image analyzer (Videomex V, Columbus, OH)
converted the analogue signal input from the video
camera to digital data. Resolution was 256 × 192
pixels and the acquisition and processing speed was
30 frames s–1. In the monitor, the video signal colors are inverted and, therefore, white objects apArchives of Insect Biochemistry and Physiology
January 2008
doi: 10.1002/arch.
Nitric Oxide and Repellency in R. prolixus
pear to be black and vice versa. Thus, the presence
of insects in the arena was determined by a visual
contrast between the individuals (white) and arena
background (dark) and scored as the number of
on pixels. Locomotor activity and repellency were
recorded using Multiple Zones Motion Monitor for
Videomex software, which records the movement
of multiple objects in an area. Each set of data was
imported and handled in a personal computer.
Bioassays: Repellency
Groups of four nymphs were used to measure
repellency. The test arena floor was covered by circular pieces of Whatman No. 1 filter paper (Whatman International Ltd., Miadstone, England), 11
cm in diameter. Each piece of paper was cut into
halves (Zone I and Zone II). Zone I was treated
with 0.35 ml acetone and Zone II was treated with
0.35 ml of a DEET solution in acetone (70 µg/cm2).
After acetone evaporation (30 min), both filter paper halves were fitted on the test arena floor. In
order to determine the distribution of nymphs on
the test arena, the TV field image was divided into
two zones using Multiple Zones Motion Monitor
for Videomex software. The area (expressed in pixels) occupied by nymphs in each zone during the
experiment was recorded for 30 min. The results
were expressed as Repellency Coefficient (RC) =
A(I) – A(II) / A(I) + A(II), where A(I) is the area
occupied by insects in Zone I and A(II) is the area
occupied in Zone II. When RC = 0, the distribution of insects is random. RC values can vary between –1 (complete attraction) and 1 (complete
repellency). The significance of the RC values were
determined using one-way ANOVA and Tukey test
for post hoc comparisons; 95% confidence limits
were calculated as described by Sokal and Rohlf
(1980). An RC was significantly different from 0
when this value is not included in the RC’s CL95%.
An additional experiment was performed to determine the presence of a possible adaptation phenomenon to DEET. Groups of four nymphs were
exposed to treated filter paper pieces with three concentrations of DEET (70, 700, and 1,750 µg/cm2)
as previously described. The area occupied by the
Archives of Insect Biochemistry and Physiology
January 2008
doi: 10.1002/arch.
3
nymphs in each zone during the experiment was
recorded during 20 min. To explore the existence
of a possible adaptation phenomenon, the total experimental time was divided into two periods of 10
min each. Then the insects’ behavior during the first
10 min was compared to their behavior during the
second period. Five independent replicates of each
experiment were performed (N = 80). The RC was
calculated for every concentration of DEET in each
time interval, and then compared statistically using
the Student’s t-test for dependent samples.
Bioassays: Locomotor Activity
Groups of four nymphs were used to measure
locomotor activity.The test arena consisted of plastic Petri dishes, 9 cm in diameter, with a circular
piece of filter paper covering the floor. Each filter
paper was treated with 0.5 ml of different concentrations of DEET solutions in acetone (70, 350, and
700 µg/cm2). Filter papers treated with 0.5 ml acetone were used as controls. The Petri dishes were
covered with gauze taped in the rear side of the
dish, and then placed inside a glass ring (5 cm
high and 10 cm diameter). Finally, the insects were
placed on the gauze (the glass ring prevented the
insects from escaping from the gauze). Locomotor
activity was registered during 60 min with the video
tracking technique described above. Four independent replicates of each experiment were performed
(N = 64).
The locomotor activity was expressed in units
of pixels/area, where “pixels” indicates the number of pixels that turned from “on” to “off” and
vice versa during the experimental time, and “area”
indicates the number of pixels “on” (area occupied by the insects). The number of pixels that
change their state when the insects walk depends
on the number of total pixels “on”; due to changes
in insect position, the number of total pixels “on”
varies during the experimental time. For this reason, we used the unit of pixels/area to normalize
the results (Alzogaray et al., 1997; Alzogaray and
Zerba, 2001). The results were analyzed by means
of one-way ANOVA and post hoc comparisons were
made with Tukey’s test for unequal N.
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Sfara et al.
To determine the effect of SNAC on locomotor
activity changes elicited by high concentrations of
DEET, two SNAC solutions in acetone (1.5 or 15
µg/insect) were topically applied to nymph antennae (see below). Following this application, the
treated insects were exposed to 350 µg/cm2 of DEET
and the locomotor activity of pre-treated insects
was measured during 60 min in the previously described device. Three independent replicates of each
experiment were performed (N = 36). Results were
compared with one-way ANOVA.
Topical Treatment in Antenna Before
Repellency Bioassays
Both antennae of each insect were topically
treated with solutions of SNAC in acetone (1.5 or
15 µg/insect). One µl per antenna of each solution was applied using a microsyringe provided
with a dispenser (Hamilton Company, Reno, NV).
This volume rapidly covers the complete antenna
surface before the solvent evaporates. Four nymphs
were used per treatment. An equal volume of acetone was applied to controls. In a previous experiment, it was demonstrated that the topical
application of acetone (1 µl/antennae) had no any
effect on the olfactory behavioral of the nymphs
when exposed to DEET (data not shown).
Immediately after the SNAC treatment, insects
were placed on the respective test arena to measure
the repellent response or locomotor activity elicited
by DEET as described above. Three independent replicates of each experiment were performed (N = 36).
The corresponding RCs were calculated, and then
statistically compared using one-way ANOVA and
Tukey’s test for post-hoc comparisons.
Two concentrations of dibutiryl-cGMP (dbcGMP), a cGMP analogue, diluted in acetone, were
tested (1 or 2 µg/insect). Each insect received 1
µl/antenna (both antennae were treated) of each
db-cGMP solution via topical application, and four
nymphs were used per treatment. An equal volume of acetone was applied to controls. Immediately after db-cGMP application, the insects were
placed on the test arena with half its surface treated
with 70 µg/cm2 of DEET, in order to determine
repellency. Three independent replicates of each
experiment were performed (N = 36). The RCs were
calculated as previously described, and then statistically compared using one-way ANOVA and Tukey’s
test for post-hoc comparisons.
RESULTS
Table 1 lists the RC values of untreated insects
exposed to acetone alone or different concentrations of DEET (70, 700, 1,750, and 3,500 µg/cm2).
The RC for the insects exposed to acetone alone
was 0.028. This value was not significantly different from 0 (because 0 was included in its CL95%,
P > 0.05), indicating that acetone did not affect the
insect behavior and the distribution of the nymphs
on the experimental arena was at random. All the
concentrations of DEET produced a significant repellency (0 was not included in their respective
CL95%, P < 0.05). Furthermore, no significant differences were observed among the effects of the
concentrations of DEET tested (one way ANOVA,
P < 0.05).
The repellency produced by 70 µg/cm2 of DEET
on untreated (RC = 0.70 ± 0.100) or acetone-treated
(RC = 0.80 ± 0.086) insects did not differ significantly (P = 0.23, Student’s t-test for independent
samples).
Figure 1 shows the effect of insect pre-treatment
with two doses of SNAC on the repellency elicited
by 70 µg/cm2 of DEET. SNAC produced a dose-dependent decrease in the repellent effect of DEET:
only the higher dose applied (15 µg/insect) reduced
TABLE 1. Repellency Coefficients (RC) of Untreated R. prolixus Nymphs
Exposed to Different Concentrations of DEET*
DEET
(µg/cm2)
0 (acetone control)
70
700
1,750
3,500
Repellency
coefficient
Standard
error
Confidence
limits (95%)
0.028 a
0.70 b
0.59 b
0.73 b
0.68 b
0.0893
0.136
0.127
0.072
0.132
–0.147 to 0.203
0.433 to 0.966
0.341 to 0.839
0.589 to 0.871
0.421 to 0.939
*Acetone control consisted of the exposure of the insects to an experimental arena
with both surfaces treated with acetone alone. Each RC value represents the mean
of five independents replicates (N = 100). Different letters indicate significant
differences (P < 0.01, one-way ANOVA, followed by Tukey test for unequal N for
post-hoc comparisons).
Archives of Insect Biochemistry and Physiology
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doi: 10.1002/arch.
Nitric Oxide and Repellency in R. prolixus
Fig. 1. Repellency coefficients (RC) for 70 µg/cm2 of
DEET on R. prolixus nymphs pretreated with nitrosoacetylcysteine (SNAC). Each bar represents the mean of
three independent replicates (N = 36). Error bars are SEM.
Different letters indicate significant differences (P < 0.05,
one-way ANOVA).
significantly the insect response to the repellent
(Tukey test for post hoc comparisons, P < 0.05).
In the other experiment, the insects were pretreated with db-cGMP. This compound reduced the
insect response to DEET in a dose-dependent way
(Fig. 2). Two doses of db-cGMP were tested, and
only the higher one (2 µg/insect) produced a significant decrease of the repellency (Tukey test for
post hoc comparisons, P < 0.05).
Fig. 2. Repellency coefficients (RC) for 70 µg/cm2 of
DEET on R. prolixus nymphs treated with dibutyryl-cyclic
GMP (db-cGMP). Each bar represents the mean of three
independent replicates (N = 36). Error bars are SEM. Different letters indicate significant differences (P < 0.05, oneway ANOVA).
Archives of Insect Biochemistry and Physiology
January 2008
doi: 10.1002/arch.
5
To determine whether the exposure to DEET
produces an adaptation phenomenon, untreated
nymphs were exposed to different concentrations
of the repellent and its effect was determined in
two consecutive time intervals of 10 min each. As
shown in Figure 3, the effect of 70 µg/cm2 of DEET
did not differ significantly between intervals
(Student’s t-test for dependent samples, P > 0.05).
However, when insects were exposed to 700 or
1,750 µg/cm2 of DEET, a significant decrease of the
repellent effect was observed in the second interval compared with the first one (Student’s t-test
for dependent samples, P < 0.05).
The effect of several concentrations of DEET (70,
350, and 700 µg/cm2) on untreated insect locomotor activity is showed in Figure 4 (according to
data in Table 1, all these concentrations produced
repellency). The locomotor activity of nymphs exposed to the lowest concentration of DEET was not
significantly different from the locomotor activity
of the control group (Tukey test for post hoc comparisons, P > 0.05), but a significant hyperactivity
was elicited by 350 and 700 µg/cm2 of the repellent (one-way ANOVA, P < 0.05).
Finally, the effect of pre-treatment with SNAC
on the hyperactivity elicited by 350 µg/cm2 of DEET
Fig. 3. Repellency coefficients (RC) obtained in two time
intervals, of untreated R. prolixus nymphs exposed to different concentrations of DEET. Each bar represents the
mean of five independent replicates (N = 80). Error bars
are SEM. Different letters indicate significant differences
(Student’s t-test for dependent samples, P < 0.05).
6
Sfara et al.
Fig. 4. Locomotor activity of untreated R. prolixus nymphs
elicited by vapors of increasing concentrations of DEET.
Each bar represents the mean of four independent replicates (N = 80). Error bars are SEM. Different letters indicate significant differences (P < 0.05, one-way ANOVA).
was studied. Figure 5 shows that no significant effects were observed when the insects received 1.5
or 15 µg/antennae of SNAC (one-way ANOVA, P
> 0.05).
DISCUSSION
The repellent effect of DEET has been widely
described for several insect species. Most studies
Fig. 5. Locomotor activity of R. prolixus nymphs treated
with two concentrations of nitroso-acetylcysteine (SNAC)
and exposed to DEET vapors (350 µg/cm2). Each bar represents the mean of three independent replicates (N = 36).
Error bars are SEM. Equal letters indicate no significant
differences among treatments (P > 0.05, one-way ANOVA).
focus their attention on the repellency response of
haematophagous insects, particularly mosquitoes.
The effect of DEET on Triatomines has been described by our laboratory for T. infestans (Alzogaray
et al., 2000; Sfara et al., 2006). These results show
that DEET doses between 7 and 700 µg/cm2 are
repellent for T. infestans nymphs. We have also observed that doses in the same range and higher
were effective repellents for fifth instar nymphs of
R. prolixus (Table 1).
Many approaches have been made since the
1970s to understand the mode of action of insect
repellents, particularly DEET. However, all the information available to the present is not enough
to comprise a convincing model of the mode of
action of this repellent. McIver (1981) suggested a
model in which DEET molecules in the vapour
phase reach the neuron membranes of chemosensory sensilla, where they interact with cell membrane lipids affecting the normal response of
sensory neurons. Burton Browne (1977) considered it necessary to study certain topics related to
orientation mechanisms involved in attraction, before discussing behavioural aspects of the repellency phenomenon. It has also been proposed that
in Aedes aegypti mosquitoes (Dogan et al., 1999),
DEET is an inhibitor of the attraction to lactic acid
rather than a repellent in itself. However, this theoretical model is not strongly supported by experimental evidence, since it has been established that
DEET itself does have a repellent effect. Our laboratory has shown the efficiency of DEET vapours
in repelling triatomines (Alzogaray et al., 2000).
We have also demonstrated that pre-treatment of
T. infestans nymphs with a sulphydryl reagent, Nethyl maleimide (NEM), known to block chemoreception, produces a reduction in the repellency of
insects exposed to DEET. Although it is accepted
that DEET acts in the vapour phase, it is not clear
whether there are specific receptors in the chemosensory sensilla of insects or not.
Topical applications of a NO donor, SNAC, produced a significant decrease in the repellent response of R. prolixus nymphs when exposed to a
repellent concentration of DEET. Many functions
Archives of Insect Biochemistry and Physiology
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doi: 10.1002/arch.
Nitric Oxide and Repellency in R. prolixus
of NO have been reported in the last few years. It
has been demonstrated that the NO/cGMP system
in the olfactory epithelium of rats is activated when
odour stimuli are presented (Breer et al., 1992). A
transient increase in cGMP and cAMP was observed
when the epithelium was stimulated with odorants. In insects, NO participates as a retrograde
messenger in sensory pathways of the visual system and in mechanosensory information processing (Bicker, 2001). It is also involved in the
processing of chemosensory signals in the antennal lobes and in the transduction of primary olfactory signals (Müller, 1997). High doses of
odorant cause a delayed but sustained increase in
cGMP levels, suggesting its implication in mechanisms of olfactory adaptation as well as in sensory
transduction following chemical stimuli (Murata
et al., 2004; Nakamura et al., 2005).
Treatment with a membrane-permeable cGMP
analogue, db-cGMP, at a dose of 2 µg/insect, also
produced a significant decrease in the repellent response of R. prolixus nymphs exposed to DEET. Considering DEET an odorant, we found that the NO/
cGMP cascade probably produced a decrease in the
perception of the repellent, and thus, a reduction
in the repellent response. To determine if this effect
could be due to an olfactory adaptation phenomenon, groups of nymphs were exposed to high concentrations of DEET, in a preliminary experiment.
When insects were exposed to 70 µg/cm2 of DEET,
a normal repellent response was observed during
the entire experimental time; however, when insects
were exposed to concentrations of 700 and 1,750
µg/cm2, a significant decrease in repellent response
was observed. Since the treatments with SNAC or
db-cGMP was focused on the insect antennae, the
results of this experiment suggest that the decrease
in RC values can be due to a sensory adaptation
phenomenon. However, the participation of some
mechanism involving the central nervous system
cannot be discarded and more experiments should
be done to elucidate this question.
Application of the membrane-permeable dbcGMP to the outer dendritic membrane of the
moth’s olfactory receptor neuron reduced its reArchives of Insect Biochemistry and Physiology
January 2008
doi: 10.1002/arch.
7
sponse to pheromones (Redkozubov, 2000). The
observed attenuated response was attributed to the
reduction of an elementary receptor current, which
elicits nerve impulses and underlies the overall receptor current. It was suggested that cGMP, the formation of which appears to be initiated by the NO
activation of soluble guanylyl cyclase (Bicker,
2001), is probably an adjustment factor of cell sensitivity in the olfactory system of insects, which
could also be involved in olfactory adaptation processes (Redkuzubov, 2000).
Exposure to increasing concentrations of DEET
produced a significant increase in the locomotor
activity of nymphs. This effect was observed when
insects were continuously exposed to 350 and 700
µg/cm2 DEET during 60 min. Hyperactivity was not
observed with the lowest dose of DEET tested (70
µg/cm2), although this dose did produce a significant repellent effect. The increase in locomotor activity was not reverted when insects were treated
with SNAC before being exposed to 350 µg/cm2
DEET. This result suggests that hyperactivity produced by the exposure of R. prolixus to DEET could
not involve the NO/cGMP transduction pathway;
furthermore, the hyperactivity phenomenon could
have a higher threshold than repellency.
In summary, this study shows that the topical
application of SNAC, a NO donor, and db-cGMP,
a membrane-permeable analogue of cGMP, reduces
DEET repellency in R. prolixus nymphs. These results represent the first evidence that the NO/cGMP
signalling system could be involved in the observed
decrease in repellent response, probably mediating a sensory adaptation phenomenon produced
by an increase in cGMP levels in the receptor neurons of R. prolixus antennae, elicited by NO. However, the NO/cGMP system does not seem to be
involved in the hyperactivity observed in insects
exposed to high concentrations of DEET.
ACKNOWLEDGMENTS
E.N.Z. and R.A.A. are members of the researcher’s career of CONICET. V.S. is a fellowship
holder of CONICET.
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Sfara et al.
LITERATURE CITED
Al-Saldoni H, Ferro A. 2004. S-nitrosothiols as nitric oxidedonors: chemistry, biology and possible future therapeutic applications. Curr Med Chem 11:2679–2690.
Alzogaray RA, Fontán A, Zerba EN. 1997. Evaluation of hyperactivity produced by pyrethroids treatment on third instar nymphs of Triatoma infestans (Hemiptera: Reduviidae).
Arch Insect Biochem Physiol 35:323–333.
Alzogaray RA, Fontán A, Zerba EN. 2000. Repellency of DEET
to nymphs of Triatoma infestans. Med Vet Entomol 14:6–10.
Alzogaray RA, Zerba EN. 2001. Third instar nymphs of Rhodnius
prolixus exposed to α-cyanopyrethroids: from hyperactivity
to death. Arch Insect Biochem Physiol 46:119–126.
Barton Browne L. 1977. Host-related responses and their suppression: some behavioral considerations. In: Shorey HH,
McKelvey J Jr, editors. Chemical control of insect behavior. New York: John Wiley & Sons. p 117–127.
Bicker G. 1998. NO news from insect brains. Trends Neurosci
21:349–355.
Bicker G. 2001. Sources and targets of nitric oxide signalling
in insects nervous systems. Cell Tissue Res 303:137–146.
Breer H, Klemm T, Boekhoff I. 1992. Nitric oxide mediated
formation of cyclic GMP in the olfactory system. Neuro
Report 3:1030–1032.
Buescher MD, Rutledge L, Wirtz RA, Nelson JH. 1985. Laboratory repellent tests against Rhodnius prolixus (Heteroptera:
Reduviidae). J Med Entomol 22:49–53.
Byler D, Gosser D, Susi H. 1983. Spectroscopic estimation of
the extent of S-nitrosothiol formation by nitrite action on
sulfhydryl groups. J Agric Food Chem 31:523–527.
Davies S. 2000. Nitric oxide signalling in insects. Insect
Biochem Mol Biol 30:1123–1138.
Dethier VG, Browne LB, Smith CN. 1960. The designation of
chemicals in terms of the responses they elicit from insects. J Econ Entomol 53:134–136.
Klun JA, Khrimian A, Debroun M. 2006. Repellent and deterrent effects of SS220, Picaridin, and DEET suppress human blood feeding by Aedes aegypti, Anopheles stephensi,
and Phlebotomus papatasi. J Med Entomol 43:34–39.
Mathews WR, Kerr SW. 1993. Biological activity of S-nitrosothiols: the role of nitric oxide. J Pharmacol Exp Ther
267:1529–1537.
McIver SB. 1981. A model for the mechanism of action of
the repellent DEET on Aedes aegypti (Diptera: Culicidae).
J Med Entomol 18:357–361.
Müller U. 1997. The nitric oxide system in insects. Progr
Neurobiol 51:363–381.
Murata Y, Mashiko M, Ozaki M, Amakawa T, Nakamura T.
2004. Intrinsic nitric oxide regulates the taste response of
the sugar receptor cell in the blowfly, Phormia regina. Chem
Senses 29:75–81.
Nakamura T, Murata Y, Mashiko M, Okano K, Satoh H, Ozaki
M, Amakawa T. 2005. The nitric oxide-cyclic GMP cascade
in sugar receptor cells of the blowfly, Phormia regina. Chem
Senses 30:1281–1282.
Ng E, Kubes P. 2003. The physiology of S-nitrosothiols: carrier molecules for nitric oxide. Can J Physiol Pharmacol
81:759–764.
Picollo MI, Seccacini E, Vassena CV, Zerba EN. 1993. Feeding and mating deterrency by sulphydryl reagents in Triatoma infestans. Acta Trop 52:297–307.
Redkozubov A. 2000. Guanosine 3′, 5′-cyclic monophosphate
reduces the response of the moth’s olfactory receptor neuron to pheromone. Chem Senses 25:381–385.
Reeder NL, Ganz PJ, Carlson JR, Saunders, CW. 2001. Isolation of a DEET-insensitive mutant of Drosophila melanogaster
(Diptera: Drosophilidae). J Econ Entomol 94:1584–1588.
Schofield CJ. 1994. Triatominae. Biología y control. [Triatominae: Biology and control.] Fernhurst, UK: Zeneca Public Health. 80 p.
Dogan EB, Ayres JW, Rossignol PA. 1999. Behavioral mode
of action of DEET: inhibition of lactic acid attraction. Med
Vet Entomol 13:97–100.
Sfara V, Zerba EN, Alzogaray RA. 2006. Toxicity of pyrethroids
and repellency of diethyltoluamide in two deltamethrin
resistant colonies of Triatoma infestans Klug, 1834 (Hemiptera: Reduviidae). Mem Ins Osw Cruz 101:89–94.
Hogg N. 2002. The biochemistry and physiology of Snitrosothiols. Ann Rev Pharm Toxicol 42:585–600.
Sokal RR, Rohlf FJ. 1980. Introducción a la bioestadística.
Barcelona: Reverté. 362 p.
Archives of Insect Biochemistry and Physiology
January 2008
doi: 10.1002/arch.
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decrease, oxide, prolixus, rhodnius, causes, nitric, repellent, deet
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