雌雄Alloxan糖尿病Wistar系シロネズミの胎児ならびに子ネズミの膵臓

抄録

The author produced alloxan diabetes in male and female animals using the Wistar-strain rats, and after the diabetes persisted for more than one month these rats were mated, and embryonal and histometrical studies of the Langerhans' islets were done in 42 cases of embryos on the 11 th, 12th, 13th, 15th, 17th and 19th day after conception and in 52 offsprings 10, 30, 90,120,180,270,360,450 and 540 days after birth (F₁). Comparing the results with the findings of 35 cases of embryos of normal rats having an identical period of conception and of 61 cases of normal rats having an identical period of conception and of 61 cases of normal rats having the identical number of days after birth, the following conclusions might be made :
(1) The primordial islet cells appeared first in dorsal pancreas primordium in normal embryos, and embryos having diabetic parents.
(2) With normal embryos, primordial islet cells appeared before the 12th day after conception, with embryos from diabetic parents, they appeared before and after the 12th day, indicating a tendency to delay slightly as compared with normal embryos.
(3) Regarding the primary large islets on the 13th day of conception, it was found that embryos from diabetic parents had considerably smaller islets as compared with normal ones, while the number of cells, also, was found to be less.
The primary small islets of embryos from diabetic parents 13 days after conception, likewise, indicated an obstructed growth (smaller number).
(4) On the 15th day of conception, the appearance of the secondary islets was noticed. With embryos from diabetic parents, however, the appearance was delayed, while the number of islet cells was delayed, while the number of islet cells was smaller.
(5) On the 15th day of conception, the primary islets of embryos from diabetic parents were seen to persist to a great extent, indicating a tendency to delay in the segmentation due to the mesenchymal tissue.
(6) On the 17th day of conception, both normal embryos and embryos from diabetic parents indicated vigorous growth and proliferation of secondary islets. In embryos from diabetic parents the number of cells constituting the secondary islets was smaller than in embryos from normal parents and they had a larger cell and islet area.
(7) On the 19th day of conception, both normal embryos and embryos from diabetic parents showed the appearance of proper Langerhans' islets. Although no difinite conclusion could be obtained on the respective time of their appearance, it was found that the average number of cells in each islet was less in embryos from diabetic parents as compared with normal ones. The respective area of cells and islets was found to be larger in the embryos from diabetic parents.
(8) Through the entire length of the embryonal period, the cells of the islets were derived, in the early stages of their appearance, from pancreas primordial cells, and, in the subsequent stages, from either the epithelium of the primitive pancreatic tubes or cells of pancreatic tubes, we saw none which originated from the cells of acinus. Also, in both categories of embryos, collapse and disappearance of the cells of the primary large islets were not seen.
(9) The number of cells in a Langerhans' islet, in the newborn rats diabetic parents (during pregnancy, mothers were not administered with insulin), showed an average decrease of about five cells, while a marked increase was seen in the size of cells and islets.
(10) On the 10th day after birth, children from diabetic parents (during pregnancy mothers were not administered with insulin) showed a decrease in the number of β-cells in each islet, as compared with normal ones (ten days after birth, an apparent distinction existed α-and β-cells), while α-cells indicated no difference in the number. The size of β-cells and islets, respectively, was still found to be slightly larger than normal.