1.Effects of organophosphorus compounds, prothiofos, cyanofenphos and chlorpyrifos on lipid metabolism in rats.
Kazumitsu HIRAI ; Takafumi TSUBOI ; Motomi TORII
Journal of the Japanese Association of Rural Medicine 1986;35(2):115-122
In order to observe the effects of organophosphorus compounds on lipid metabolism, 4mg of prothiofos, cyanofenphos or 1mg of chlorpyrifos were administered per os to different groups of rats, and the results were as follows;
1) Serum cholinesterase activity was significantly suppressed in the experimental group administered these pesticides compared with the control group, administered salad oil only.
2) The lipase activity in the liver was suppressed by administration of prothiofos and that in the kidney was also suppressed by cyanofenphos. There was a close positive correlation between the cholinesterase and lipase activity in epididymal adipose tissues of rats administered prothiofos or cyanofenphos. Furthermore, the positive correlation between the cholinesterase and lipase activity in the kidney was close on day 2 after administration.
3) The acyl CoA synthetase activity in the liver of rats administered cyanofenphos was signifcantly lower than that of the control group, and there was close positive correlation between the cholinesterase and acyl CoA synthetase activity in the rats administered prothiofos.
4) The serum concentration of beta-lipoprotein decreased in the group administered cyanofenphos or chlorpyrifos.
5) The suppression of the lipase and acyl CoA synthetase activity was independent of the serum concentration of immunoreactive insulin.
2.Effects of organophosphorus compound, cyanofenphos on the glucose metabolism in rats.
Kazumitsu HIRAI ; Takafumi TSUBOI ; Motomi TORII
Journal of the Japanese Association of Rural Medicine 1987;35(5):881-886
In order to observe the effect of organophosphorus compound, cyanofenphos (0-ethyl 0-4 -cyanophenyl phenylphosphonothioate) (CYP) on the glucose metabolism, 20 mg/kg of CYP was repeatedly administered per os to male Wistar rats, weighing approximately 150g. The supression of the serum and brain cholinesterase activity increased with times of administration, but muscular strength of extremities was not suppressed. The concentration of serum glucose, however, was enhanced in spite of the increase in the concentration of serum insulin. The mechanism of hyperglucosaemia resulted from the supression of the incorporation of glucose into cells in peripheral tissues without the activation of glycogen phosphorylase and suppression of glycogen synthetase activity. It was suggested that the suppression of the incorporation of gulcose into cells resulted from inhibition of insulin receptors or entry sites of glucose in cells by cyanofenphos.
The relation between disturbances of the glucose metabolism and the delayed neurotoxicity was discussed.
3.Effects of the organophosphorus and carbamate insecticides on lipid metabolism
Kazumitsu Hirai ; Kuninori Shiwaku ; Motomi Torii
Journal of the Japanese Association of Rural Medicine 1982;31(1):1-6
On effects of various organophosphorus insecticides such as chlorfenvinphos (phosphate type), EPN (phosphonothionate type), fenitrothion (phosphorothionate type) and mecarbam (phosphorothiolothionate type), and carbaryl (carbamate) on serum pseudocholinesterase, serum nonspecific esterase, serum lipoprotein lipase, adipose tissue lipase and epinephrineinduced lipolysis, this investigation was caried out in vitro. The results were as follows;
1. These insecticides caused a dose-dependent inhibition of serum nonspecific esterase activity as well as serum pseudocholinesterase. Chlorfenvinphos exhibited the strongest inhibition of serum pseudocholinesterase, but severe inhibition of serum nonspecific esterase was recognized carbaryl rather than chlorfenvinphos.
2. Carbaryl and fenitrothion caused slight stimulation of the serum lipoprotein lipase activity with addition of 10-5 M, but inhibited this enzyme with 10-3 M of these insecticides
3. Addition of 10-3 M of these insecticides caused inhibition of adipose tissue lipase in lipolytic system using ediol as substrate. These insecticides also inhibited epinephrineinduced lipolysis as well as inhibition of the adipose tissue lipase.
4. On the base of these findings, it was suggested that these insecticides caused the inhibition of lipolysis by direct suppression of adipose tissue lipase without reference to cAMP dependent proteinkinase.
4.Annual Studies on Health Conditions of Aged Bedridden Patients at Home in Rural District
Kuninori SHIWAKU ; Noriyuki NITTA ; Kazumitsu HIRAI ; Motomi TORII ; Takafumi TSUBOI
Journal of the Japanese Association of Rural Medicine 1984;32(5):945-951
In the present study, we undertook the annual investigation on health conditions of aged bedridden patients at home from 1971 to 1979 in Hiromi Cho, Ehime Prefecture.
The incidence rate of bedridden patients in 1971 was 3.7 % in the population of 65 years old and over, and 0.499 % in the population of Hiromi Cho. Paticularly, the latter rate was very higher than that in urban areas. The bedridden patients had been caused by apoplexy, senility, loss of eyesight, fracture and rheumatoid arthritis. 66.7 % of bed rest were caused by apoplexy. The bedridden age was 70.1±7.1 years in men, 71.2±11.6 years in women. The bedridden age in rheumatoid arthritis women was 41.0±1.0 years. The activity of dayly life in the bedridden patients lowered with the period of bed rest, and was dependent on the original diseases of bedridden. Their mortality rate was about 50 % after 2 years and about 90 % after 8 years. Their relatives mainly cared the bedridden patients. The bedridden patients were not cared in full, because 70 % in their sick nurses had their jobs.
We think that the best plan to bedridden patients is to prevent the diseases causing prolonged bed rest.
5.Health Hazards by Pesticides on Farmers in Citrat Fruit Area.
Kuninori Shiwaku ; Kazumitsu Hirai ; Motomi Torii ; Yasuaki Mima
Journal of the Japanese Association of Rural Medicine 1982;30(6):1028-1033
Blood enzymes and lipids that might cause fluctuations with organophosphate pesticides were measured before and after spraying mecarbam with the conventional way using the nozzle on 76 farmers (37 males and 39 females) in citrat fluit area of Ehime Prefeture.
1. Serum pseudocholinesterase activity measured by the method of Voss et al. was found to be reduced significantly in the female group after spraying over 2 l mecarbam (P>0.05) and remained to be the control level in other groups after spraying.
2. The values of serum pseudocholinesterase activity measured by the method of Bellino et al. was correlated (γ=0.78) with the values by the method of Voss et al., but erythrocyte acetylcholinesterase activity measured by the method of Bellino et al. did not show any fluctuation after spraying in all the groups.
3. There was no increase in both β-glucronidase and alkaline phosphatase activity in sera.
4. Total cholesterol and HDL-cholesterol levels in sera decreased significantly in males (P<0.05), but did not decrease in females after spraying.
Based on these results, we suggested that spraying of mecarbam for 4 hours with wearing protectors might not induced any danger in farmers.
6.Health Hazards by Spraying Pesticides on Farmers in Citrus Fruit Area
Kuninori Shiwaku ; Kazumitsu Hirai ; Motomi Torii ; Takafumi Tsuboi ; Yasuaki Mima
Journal of the Japanese Association of Rural Medicine 1982;31(2):64-68
In the present study, we undertook the investigation into health conditions and subjective symptomes by spraying pesticides on farmers in citrus fruit area in Ehime Prefecture.
65 males and 138 females were examined for their health conditions in August, 1981 and the prevalence rate of anemia was 6.2% in males and 37.0% in females, that of hypertension was 20.0% in males and 20.3% in females, and that of the disturbance of liver function was 17.0% in males and 2.8% in females. There was a serious problem in farmers that the subjects taken these diseases usually sprayed pesticides.
The investigation into subjective symptomes by spraying pesticides was performed for 50 males and 54 females from May to July, 1981. The frequency of spraying pesticides was about 2.5 times per sprayer in May and June, but about 5 times in July. Time of spraying was about 5 hours and dithiocarbamates was most frequently used. The tendency of combinational use with several pesticides was recognized in July than in May and June. The wearing rates of waterproof coat and trausers were high but those of dustproof mask and rubber gloves were low. The incidence rate of subjective symptomes by spraying pesticides was 10.4% in males and 17.0% in females in May, 14.3% in males and 27.8% in females in June, and increased to 42.0% in males and 63.0% in females in July. Skin lesion was the most frequent symptome, excessive sweating and general fatigue followed this. Further studies on skin hazards due to pesticides are necessary.
7.Skin Hazards Caused by Pesticides on Farmers in Citrus Fruit Area
Kuninori Shiwaku ; Kazumitsu Hirai ; Motomi Torii ; Takafumi Tsuboi
Journal of the Japanese Association of Rural Medicine 1983;32(1):22-28
In the present study, we undertook the investigation into skin hazards caused by pesticides on farmers in citrus fruit area in Ehime Prefecture from May to September, 1981.
1) 71.4% in males and 68.5% in females were recognized to have had the contact dermatitis due to pesticides. Dithianone, maneb and manzeb were pesticides which frequently caused skin lesions.
2) The incidence rate of skin hazards caused by spraying pesticides was 0% in males and 3.8% in females in May, 8.2% in males and 13.0% in females in June, and increased to 26.0% in males and 50.0% in females in July.
3) The highest incidence rate on skin lesions due to pesticides in July were observed in farmers who had been engaged in the spraying, and the next dangerous work was the thinning out the superfluous fruits, followed by weeding and so forth.
4) Positive reaction of patch testing was revealed in 0%, 18.8% and 50.0%, with 0.01%, 0.1% and 0.5% preparations of dithianone, and negative reactions were revealed with preparations of thiophanate-methyl, maneb and manzeb, respectively.
These observations suggest that the mechanism of skin lesions due to pesticides was mainly the primary irritating type of contact dermatitis, and that spraying in combination with several pesticides, sweating and hard sunlight take part in skin lesions.
8.A Epidemiological Study on Pseudocholinesterase in Citrut Fruit Area with Special Reference to the Relationship on Serum Lipids
Kazumitsu Hirai ; Hiromichi Okuda ; Kuninori Shiwaku ; Toshiharu Muraoka ; Naohisa Okada ; Motomi Torii
Journal of the Japanese Association of Rural Medicine 1980;29(4):672-677
Based on previous anther's obsarbations of pseudocholinesterase (PCE) activity correlated with total cholesterol, fluctuation of this enzyme was epidemiologically studied in connection with changes of serum lipids on 225 sprayers of pesticides in citrut fruit area, and results are as follows;
1. PCE activity was slightly correlated with serum triglyceride (γ=0.277) and total cholesterol (γ=0.431) in females but not correlated in males.
2. PCE activity was significantly higher (P<0.05) in hyperlipemic subjects than normolipemic, and obviously higher (P<0.001) in hyperlipemic over weight subjects than hyperlipemic normal weight.
3. The enzyme activity was significantly higher (P<0.05) in hypertriglyceridemic subjects than in normolipemic, and highest (P<0.01) in subjects with hypertriglyceridemia and hypercholesteremia.
4. Serum triglyceride values in males and serum cholesterol values in females were obviously higher (P<0.05) in the high level group of PCE activity than in the low level group.
5. PCE activity was exhibited a tendency of elevation in hypertensive females than in normal blood pressure, and slightly correlated with systoric blood pressure (γ=0.286) and diastoric blood pressure (γ=0.358) in females.
6. PCE activity was found to be lower (P<0.05) in arterioslerotic subjects than nonsclerotic subjects with ocular funduscopic findings.
These epidemiological findings suggested that PCE might play a role in lipid metabolism and reduction of this enzyme might cause disturbances of lipid metabolism.
9.Nutrients Intake and Complications of Hypertension in a Rural Area. Special Reference to Agricultural Working Days.
Kazumitsu HIRAI ; Takafumi TSUBOI ; Motomi TORII ; Yasuko ISSIKI ; Chiyoko YAMANAKA ; Naoko WADA
Journal of the Japanese Association of Rural Medicine 1991;40(1):1-11
This study was carried out to investigate the relationships among the agriculturalworking days, nutrients intake and complications of hypertension in 266 male subjects in a ruralarea. The main findings are as follows.
1. Salt and carbohydrate intake and cereal energy level were higher in the farming group, who engaged in agricultural work for 300 days or over in a year, than in the non-faming group.
2. The hypertensive group with abnormal ECG or fundscopic findings showed a lower protein energy ratio, fat energy ratio and animal protein ratio than the non-hypertensive group with normal ECG and fundscopic findings.
3. The serum total cholesterol level of the farming group was lower than that of the non-farming group. The hypertensive group with abnormal ECG or fundscopic findings showed lower serum total cholesterol level than non-hypertensive group with normal ECG and fundscopic findings.
These results suggest that the complications of hypertension, such as abnormal ECG or funds-copic findings, are aggravated by the dietary habits of the farming group.