Factors affecting the efficacy of warfarin to roof rat rattus rattus in egypt
Abstract: Several field and laboratory experiments had been conducted to detect the relative susceptibility of roof rat R. rattus individuals, collected from Menofia; Behira and Ismailia Governorates to warfarin anticoagulant in comparison with those collected from Abo-Rawash area which did not exposed previously to any type of rodenticides.
The results obtained could be summarized as follows:
1- Field Studies
1-1- Rodenticides Raekhistory
Data of the amounts of rodenticides used in Menofia Governorate (Quesna District), Behira Gov. (Tahrir Province) and Iamailia Gov. (Ismailia Dist.) during the period from 1985-1994 were gathered from different Governmental sources. the maximum amount of rodenticides per feddan was recorded in Menofia followed by Behira and Iamailia Gov., i.e. the total amount/feddan in Tahrir Province and Ismailia Dist., represented ca. 64.3 and 41.6% from the total amount used in Quesna District.
1-2- Survey and Distribution of Rodent Species
Rodent fauna of Menofia, Behira and Ismailia Governorates was studied in three different habitats (farmers houses, fields and poultry farms). Results showed that the roof rat Rclttus rattars was the most dominant species in all tested habitats of most Governorates followed by the Norway rat R. norvegicus while the Nile rat Arvicanthis niloticics was found in fields of Menofia Gov. The house mouse Mus musczchcs was found in houses of the three Governorates and was recorded in the fields of Ismailia Gov. The Egyptian spiny mouse Acomys cahirinus was found in few numbers in houses of Behira Governorate.
2- Laboratory Studies
2-1- Acute Oral Toxicity
The LD50 of warfarin to R. rattus individuals trapped from Menofia, Behira and Ismailia Governorates was studied and compared with those collected from the untreated areas of Abo-Rawash. Animals were treated orally with serial doses of warfarin and percentage mortality was recorded. The calculated LD50 showed that animals from Menofia exhibited a considerable tolerance level to warfarin followed by those from Behira and Ismailia Gov., when compared with the susceptible individuals of Abo-Rawash area i.e. LD50 values were 92.6, 88.0, 82.5 and 75.0 mg/kg.w, respectively.
2-2- Lethal Feeding Periods (LFP)
Rats were fed on warfarin bait 0.025% for various fixed days and the corresponding mortality was recorded. The calculated lethal feeding periods LFP50& LFP99 indicated that the situation of susceptibility of R. rattus from various areas in the present work is completely parallel to the results of LD50 where rats of Menofia Gov. showed more tolerance to warfarin followed by those from Behira and Ismailia Gov., i.e. LFP50 & LFP99 values were (3.2 & 9.8), (3.1 & 9.4) and (2.9 & 8.5) days, respectively in comparison with (2.8 & 6.2) days for animals from the untreated areas of Abo-Rawash.
2-3- Clotting Parameters in Relation to Susceptibility to Warfarin
Effect of warfarin on bleeding time (B.T.), prothrombin time (P.T.), and activated partial thromboplastin time (A.P.T.T.) of R. rattus individuals collected from different Governorates mentioned above to warfarin in comparison with those trapped from untreated areas of Abo¬-Rawash was studied. Warfarin effect was obviously noticed in the case of animals from Abo-Rawash area whereas B.T., P. T., A.P.T.T. values were considerably increased after treatment with 3.5, 3.6 and 5.3 times than pre treatment. The lowest effect was observed on rats of Menofia Gov. followed by Behira and Ismailia Governorate.
2-4- Susceptibility of R. rattus Trapped from Different Habitats
Response of R. rattus individuals trapped from different habitats of Menofia Gov. (houses, fields and poultry farms) to warfarin was determined using the lethal feeding technique and also some biochemical parameters (B.T.), (P.T.) and (A.P.T.T.) were measured. Rats from poultry farms proved to be the most tolerant followed by those from fields while animals trapped from houses exhibited relative sensitivity to warfarin i.e., LFP50 and LFP99 values were (3.8 & 12.5), (3.5 & 9.5) and (2.9 R; 9.3) days, respectively. The biochemical response revealed the same trend of LFP values.
2-5-Effect of Food Type on the Susceptibility of R. rattus to Warfarin
The effect of dietary content of each habitat on the susceptibility of R. rattus to warfarin was studied under laboratory conditions. Animals were divided into three groups; the first were fed on foodstuffs (dry bread, flafel and crushed maize), the second on some vegetables (tomato, carrot, cucumber and squash) while the third fed on poultry fodder, representing the domenant foods in houses, fields and poultry farms, respectively. After 60 successive days feeding, the response of these animals to warfarin was studied using lethal feeding period and biochemcia methods. Rats fed on poultry fodder showed a relatively higher tolerance than the others fed on vegetables or foodstuffs. LFP50 & LFP99 values were (2.6 & 5.9), (3,0 & 6.0) and (3.7 & 10.1) days for animales fed on foodstuffs, vegetables and poultry fodder, respectively. The biochemical parameters response B.T., P.T. and A.P.T,T. revealed . the same pattern of LFP values.
2-6- Effect of Food Type on Plasma Protein Bands
Effect of different food hypes (poultry fodder, vegetables and foodstuffs) on plasma protein bands of R. rattus was studied pre and post injection with warfarin + vitamin K epoxide. 17 different protein bands of different molecular weights were separated and visualized in plasma of the three treatments. The bands of Rf (0.47 and 0.63) which have molecular weights (34493 and 40806 kDa) appeared only in the case of poultry fodder. Two other protein bands with Rf (0.30 and 0,41) of molecular weights (72643 and 60572 kDa) were found in the plasma of animals fed on poultry fodder or vegetables, but they were absent in the case of foodstuffs which consider the poorest diet in the three food groups.
2-7-Screening of Some Potentiators to Overcome The Tolerance of R. rattus to Warfarin
The effect of some potentiators on the toxicity of warfarin to R. rattus collected from poultry farms that exhibited tolerance was studied. Animals were divided into four groups, the first was fed on warfarin bait 0.025%. The second was fed on mixture of warfarin + calciferol and the third on a mixture of warfarin + L-histidine. The fourth group was fed on a mixture of warfarin + sulphaquinoxaline for 7 days. When warfarin bait was used only 60 % of animals were killed, but when calciferol, L¬histidine and sulphaduinoxaline were mixed with warfarin, the toxic effect of warfarin was enhanced to cause 100, 90 and 70% mortality, respectively.
Publication year 1997
Availability location معهد بحوث وقاية النبات - ش نادى الصيد - الدقى - جيزة
Availability number
Organization Name
Country Egypt
Publisher Name: كليه الزراعة-جامعه القاهرة
Place: حيزه-مصر
Author(s) from ARC
Agris Categories Protection of plants - General aspects
AGROVOC
TERMS		 Acute toxicity. Anticoagulants. Blood proteins. Egypt. Laboratory animals. Rats. Rodenticides. Warfarin.
Publication Type PhD Thesis
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