1988 Fiscal Year Final Research Report Summary
A new non-obese, non-ketotic diabetic strain of the Chinese hamster :a possible role of adrenals in pathogenesis.
Project/Area Number |
61480450
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
Laboratory animal science
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Research Institution | Tokyo Medical College |
Principal Investigator |
KOMEDA Kajuro Animal Research Center, 医学部, 助教授 (90074533)
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Project Period (FY) |
1986 – 1988
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Keywords | Diabetes / Chinese hamster / Sex difference / Plasma cotisol levels / Plasma ACTH / Adrenalectomy / B-cell morphology |
Research Abstract |
A spontaneously diabetic inbred strain of Chinese hamsters has been established in our laboratory by mating glycosuric brothers and nonglycosuric sisters for more than 20 generations. After 5-6 generations, 80-90% of the males became overt diabetics without ketonuria from 5-8 monthold. These animals did not show obesity throughout their lives. Only limited females(9% or less)became overt diabetics. The present study was designed to expore the pathogenesis of diabetes in these animals. Castration and ovariectomy did not have any effects on the cumulative incidebce of diabetes. In the diabetic strain, regardless of the presence of glycosuria, the plasma cortisol levels were 3-4 times higher in the males than in the females and in the non-diabetic age-matched control strain. Hypertrophy in the zona fasciculata cells of the adrenals from the males of the diabetic strain was also shown in this period. Plasma ACTH levels of hamsters with or without overt diabetes, and non-diabetic age-matched controls did not show sny significant difference at 3,5 or 8 month-old. Adrenalectomy at the age of 4-l months suppressed significantly the incidence of overt diabetes in the males from the sham-operated control. Adrenalectomy of males with mild diabetes showed decreased blood glucose levlels, and increased glucose tolerance, the B-cell morphology of these animals showed less degranulation. The above data indicate that glucocorticoid plays some role in the pathogenesis of diabetes in this strain.
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