VOLUM OMAGIAL - Facultatea de Ştiinţe ale Naturii şi Ştiinţe Agricole

The action of some insecticides.../ Ovidius University Annals, Biology-Ecology Series 14: 79-82 (2010)
running water which was changed everyday, (1) one
lot containing animals which were subjected to
treatment with insecticide and kept at 4-6ºC, (2) a
second lot containing animals which were subjected
to treatment with insecticide and kept at 22-24ºC.
The toxic was administered by intraperitoneal
shots, one shot every two days, in a scheme of 3
weeks. The administered dosage of insecticide was
not lethal as none of the subjects died through the
experiment. We used three different types of
insecticide: Carbetox (active substance is malathion)
in a dose of 0.01ml/g body weight, Actara 25WG
(active substance is thiamethoxame) in a dose of
0.4mg/g body weight and Reldan 40EC (active
substance is chloropyrifos-methyl) in a dose of
0.01ml/g body weight.
The number of erythrocytes and leukocytes was
microscopically determined with a Thoma cells
numbering chamber, by using a small amount of
blood collected from the heart [6]; the glycemia level
has been determinate using an Accutrend GCT.
3. Results and Discussions
The number of erythrocytes in the frog
individuals subjected for three weeks to treatment
with 0.01ml/g body weight of Carbetox was
significantly affected as shown in Figure 1. The
difference between the number of erythrocytes which
was determined for the control and the ‘treated’ lot at
4-6ºC, an average decrease of 16.68% was found in
the treated frog individuals who seemed to be related
to the intense hemolytic activity. At 22-24ºC we
registered a decrease with 37.01% in a number of
erythrocytes.
In animals treated with Actara 25WG in a dose
of 0.4mg/g body weight, there has been a decrease in
the number of erythrocytes with 35.11% to the
control value for specimens kept at 4-6°C and with
37.42% for animals treated with insecticide and kept
at 22-24°C.
We mention that similar results in the number of
erythrocytes in the lake frog were obtained by other
researchers in similar experimental conditions in fish.
Thus, Ponepal [7] found a decrease in the number of
erythrocytes in fish under the action of Actara 25WG
insecticide, as well as a decrease in the oxygen
consumption. Also, Dhembare [8] recorded decreased
80
hemoglobin, the number of erythrocytes, leukocytes
and platelets in fishes were exposed to LC50 of some
insecticides for seven days.
As shown in Figure 1, as compared to the values
recorded for the control individuals of frog, the
number of erythrocytes increases by 51.14% for the
animals which were treated with Reldan 40EC in a
dose of 0.01 ml/g of body weight and kept at 4-6ºC,
while animals treated with the same concentration of
Reldan 40EC but kept at 22-24ºC the number of
erythrocytes increases by 76.88%. Increased number
of erythrocytes under the action of Reldan 40EC has
also been noticed by Păunescu et al [9].
number of erythrocytes/ml blood
1000000
900000
800000
700000
600000
500000
400000
300000
200000
100000
0
358166.7
481111.1
298400
225608.2
232405.6
301077.8
851000
691888.9
control Carbetox Actara 25WG Reldan 40EC
Fig. 1. The influence of some insecticide upon
number of erythrocytes in Rana (Pelophylax)
ridibunda
4-6ºC
22-24ºC
The number of leukocytes (Fig.2) at the two
heat levels registered similar changes to that of the
number of red blood cells as can be seen in Figure 1.
Carbetox insecticide in a dose of 0.01ml/g body
weight determined a decrease in number of
leukocytes with 87.26% as compared with the witness
value, at 4-6ºC. An intensive leucopenia was also
registered at 22-24ºC, when the number of leukocytes
decreases with 101.93%. The number of leukocytes
decreases by 28.52% to the witness for animals
treated with Actara 25WG and kept at 4-6°C, while
the value of this index is lower, 62.06% as compared
to the witness, at higher temperatures
(22-24ºC). Reldan 40EC in a dose of 0.01 ml/g of
body weight was also affected the number of
leukocytes. As shown in figure 2, the difference
between the number of leukocytes which was
determined for the control kept at 4-6ºC and the
‘treated’ lot kept at the same temperature, an average