Prospective investigations of long-term normoglycaemic BB/OK-rats: serial determination of glucose tolerance, insulitis, B-cell volume density and pancreatic insulin content.
Pancreatic tissue was obtained by repeated surgical biopsies from BB/OK rats (n = 62), which maintained normoglycaemia up to 250 days. The tissue was used to determine pancreatic insulin content, islet volume density, pancreatic B-cell volume density and the presence of mononuclear cell infiltrations within and around pancreatic islets (insulitis). The BB/OK rats were also characterized by determination of glucose tolerance. In 50 d old BB/OK rats lymphatic infiltration of pancreatic islets are rare. The mean value of relative B-cell volume density amounted to 0.71 +/- 0.05% and the pancreatic insulin content was 21.31 +/- 1.29 pmol/mg wet weight. 70 d old BB/OK rats are characterized by an identical relative B-cell volume density and pancreatic insulin content, although in 70% of the animals an invasion of immunocytes could be observed. At an age of 90 and 120 d the BB/OK rats were characterized by an increased number of islets having insulitis accompanied by a decrease of pancreatic insulin content and B-cell volume density. The individual evaluation of the investigated BB/OK rats revealed in each animal the presence of insulitis accompanied by a decreased B-cell volume density and a diminished pancreatic insulin content. Animals older than 120 d do reenhance the pancreatic insulin content and B-cell volume density attended by an impairment of glucose tolerance. The results suggest that all BB/OK rats are characterized by a spontaneous pancreatic B-cell destruction, which was arrested and/or interrupted in the animals maintaining normoglycaemia up to 250 d.
Hahn
H J
HJ
Institute of Diabetes Gerhardt Katsch, Karlsburg/Germany.
Lucke
S
S
Klöting
I
I
Besch
W
W
D000375:Aging; D000818:Animals; D001706:Biopsy; D001786:Blood Glucose / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000473:pathology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000473:pathology*; D005951:Glucose Tolerance Test; D007328:Insulin / Q000378:metabolism*; D007515:Islets of Langerhans / Q000473:pathology*; D051381:Rats; D011913:Rats, Inbred BB
D001786:Blood Glucose; D007328:Insulin