Abstract
In our foregoing report, it was shown that the total islet volume Vi of the pancreas represents the sole morphological index of glucose tolerance and intolerance. As a further extension of that study, we examined the relative volumes of A, B and D cells in diabetes histometrically, and correlated them with clinical data. Autopsy pancreases from 26 maturity-onset and 5 juvenile-onset diabetics and 18 nondiabetics were subjected to volumetry. For differential staining of specific granules, paraffin sections from each pancreas were treated by Gomori's aldehyde fuchsin trichrome method. The volume ratio between the different islet cells in the sections was determined by the point counting method using a square-lattice eye-piece.
The results obtained may be summarized as follows.
1) The volume ratio between A, B and D cells was almost the same in the diabetic groups as in the controls. Especially noteworthy was the fact that the percentile volume of B cells was constantly about 65% in all three groups.
2) The absolute total volume VB of B cells in the pancreas was 0.64 cm3 in the control, but only 0.39 and 0.16 cm3 in the maturity-onset and juvenile-onset diabetic groups, respectively. The total volume of A cells was also reduced in the diabetic groups.
3) BSmax, the maximum blood sugar level during oral GTT, increased with decreasing total B cell volume VB. There were some nondiabetics with smaller VB and concomitantlysomewhat higher BSmax, and these overlapped with diabetics in the range of VB from 0.4 to 0.6 cm3. It seems quite likely that such cases represented potential diabetics (socalled prediabetics), and may be defined as such by the transitional nature of not only their clinical but also their morphological features.
4) In the diabetic group, the smaller the value of VB, the higher was the level of fasting blood sugar.
5) VB diminished with descending age at onset of diabetes.
All the above findings areconsidered to support the primacy of insulin deficiency in the pat hophysiology of diabetes.
