Effects of X-ray Irradiation on the infectivity and reproductivity of clonorchis sinensis
Parthes(1904) reported the influence of X-ray irradiation upon nematodes, and stated that growth of irradiated parasites was inhibited. Lagrange(1964) experienced that the mice which were infected with X-ray irradiated metacercariae of Fasciola hepatica were alive, but those which were infected with non-irradiated
metacercariae were all perished. Villela et al.(1961, 1962), Redke and Sadun(1963), Lichtenberg et al.(1963) and Sadun(1963) reported that the resistance was produced in the hosts, when irradiated cercariae of Schistosoma mansoni were inoculated into
mice and monkeys.
Miller(1964) reported that X-ray irradiation upon Ancylostoma caninum decreased the infectivity and induced the sterility.
The present study was designed to study the influence of X-ray irradiation upon the following subjects; infectivity and reproductivity of liver fluke, and the pathological changes, blood glucose and serum 7-globulin in the host.
Materials and Methods
Animals: Twenty-four healthy rats(180-200g) and 24 white rabbits(1.8-2.0kg) were used for the experiment.
metacercariae; Metacercariae of Clonofchis sinensis were collected by digestion method from fresh water fish caught from an endemic area(Iri and Ok-Ku, Cholla-puk-Do).
X-ray irradiation; Each of metacerceriae, rats and rabbits were irradiated with 300, 500 and 1,000R at 24。C room temperature (100kv. 15mA. at a distance of 500cm without filter).
Blood glucose; Micromethod was applied 0.1ml of blood was dyed with alkalin copper solution and read by 420mμ Junior spectrophotometer and calculated by following formula.
-Density of unknown/Density of standard×mg of glucose×8/16×100/0.05=mg%
Serum γ-globulin; Paper electrophoresis was applied. Serum was run on the filter paper (Whatman No.1) for 16 hours and dyed with bromphenol blue. Each fraction was elutriated by 0.1% Na^^1CO^^3 and read by 520mμ Junior spectrophotometer.
Irrdiation (1); X-ray irradiated (300, 500 and 1,000R) 50 metacerariae were introduced into the stomach of each of 12 rats and 12 rabbits. Twenty-six to 46 days after the infection E.P.G.(eggs per gram) were counted by Stoll's egg counting
method. Blood glucose and γ-globulin of rabbits were measured for 42 days once every week.
Adult worms were recovered from the sacrificed animal on the 46th after the infection. The pathological of liver, hypophysis, kidney and adrenal glands were examined and sex organs were also observed.
Irradiation (2); X-ray irradiated animals were infected with 50 non-irradiated metacercaria each, and follow up examinations were done as in irradiation.
1. Infectivity and reproductivity of X-ray irradiated metacercariae.
The E.P.G. of 300 and 500R irradiated rat groups(680 in the former, 693 in the latter) were slightly decreased compared with the control rat group 9892 eggs), in 1,000R rat group it decreased to 253. E.P.G.P.W. (eggs per gram per worm) of 300
and 500R irradiated group (43 and 63 each) showed no difference compared with 39 of control group, and in 1,000R group the E.P.G.P.W. showed only 28 eggs.
In 300 and 500R rat group, the number of worms recovered was 16 and 19, and 23 worms in control rat group, in 1,000R group 9 worms were recovered.
In rabbit groups the result was almost same as in the rat groups.
2. Infectivity and reproductivity of liver fluke in X-ray irradiated rats and rabbits.
500R and 1000R irradiated animals to which 50 metacercaria were infected all perished. In 300R irradiated animal group(E.P.G. :rat; 787, rabbit; 12,733), there was no significant difference in egg laying capacity comparing control group (rat; 893, rabbit; 8,490).
The number of worms from a rat and rabbit were similar to that of control group (23 and 14 worms).
3. Pathological changes of rats infected with X-ray irradiated metacercarise.
In the liver tissue of rats infected with 300R irradiated metacercariae, hepatic cells were degenerated, and in 500R group those were slightly degenerated. In 1,000R group the liver tissue was similar to the normal rats. There were no changes in hypophysis, kidney, and adrenal grands of those animals.
4. Pathological changes of X-ray irradiated rats infected with non-irradiated metecercariae.
In 300R group the degeneration of hepatic cells was similar to that of control group, but the changes were remarkable in 500 and 1,000R group.
5. Blood glucose of rabbits infected with X-ray irradiated metacercariae similar to that of control group. In the group of 300R irradiated rabbits, blood blucose was increased after the infection with non-irradiated metacercariae.
6. Serum γ-globulin of rabbits by X-ray irradiation.
In 1,000R irradiated group the γ-globulin increased after 4 weeks of infection, but in the 300R irradiated group, the γ-globulin was decreased comparing with control group.
The influences of X-ray irradiation to parasite and hosts were studied. Irradiated metacercariae of Clonorchis sinensis were infected to normal rabbis and rats. The irradiated hosts were also infected by the non-irradiated metacercariae.
The infectivity and reproductivity of the parasite and the pathological changes, blood glucose and serum γ-globulin of the hosts were examined.
1. Infectivity of Clonorchis sinensis was inhibited at dosage of 1,000R X-ray irradiation upon the metacercariae.
2. Reproductivity of Clonorchis sinensis slightly decreased at dosage of 500R and highly decreased at 1,000R irradiation upon the metacercariae.
3. The rats could not survive at 500R and 1,000R irradiation and survived only at 300R. In 300Rgroup, there was no any difference with control in regard to infectivity and reproductivity of Clonorchis sinensis.
4. The pathological of the host infected with X-ray irradiated metaceraiae were mild. The more the dosage of X-ray irradiation, the changes were observed.
5. In the rabbits which were infected with X-ray irradiated metacercaria group the blood glucose did not showed high level.
6. γ-globulin was remarkably increased in the group of 1,000R irradiated metacercarise.
7. In the irradiate host, γ-globulin decreased more than that of non-irradiated group.
From the above results it was concluded that X-ray irradiation to the metaceraiae of Clonorchis sinensis may decrease the infectivity and reproductivity of the parasite, but it amy give resistance to the host. On the other hand, the irradiation upon the host may result the decrease of resistance against the
infection of Clonorchis sinensis.