Enzyme Histochemistry in Experimental Diabetes Mellitus

Abstract

SYNOPSISReported here, are the observations on various histochemical enzyme reactions in several organs (the liver; the kidney; the cardiac, diaphragm, and femoral muscles; the duodenum; the adrenal gland) of rabbits which had been rendered diabetic for from 3 days up to 1 year or more. Independent of the diabetes-inducing reagents (Alloxan or Dithizone) used, the following similar results were obtained: With SD, LD and DPND (which are related to the Krebs cycle activity) and with such phosphatases as ACPase and ALPase, a distinct activity increase could be seen in the liver, the kidney, and the muscular system; except with SD, however, this increase tended to become indistinct or even slightly reduced when 1, 2, or 4 months had elapsed after the induction of diabetes.With G-6-PD (which is related to HMP cycle activity), a distinct decrease in the liver and the kidney could be seen throughout all the diabetic stages. The changes in Ph-rylase activity ran roughly parallel to those in glycogen content, but contradictory changes were found between activity and content in the lipemic heart. Regarding ATPase activity in the lipemic animals, a heavily stained membrane activity could be noted in the liver, the kidney and the cardiac muscle. The lipemic animals also revealed a remarkable increase in non-specific esterase. On the findings in the adrenals, the activities of G-6-PD, SD, ACPase, and ALPase had all been reduced, particularly in the fasciculata when diabetes had persisted for more than 2 or 3 weeks, and ran fairly parallel with the urinary 17-KS and 17-OHCS contents.In addition to these findings, such interesting phenomena were noted as the tendency for the specific zonation of hepatic enzyme distribution to become obscure, the presence of an intimate relation between the activity changes in the liver and the kidney, and the presence of relatively specific activity distribution patterns in the various organs of rabbits having sustained experimental congenital diabetes for more than 1 year.The specific cytotoxic effects of alloxan on pancreatic islets were first studied by Dunn, Sheehan and McLetchie (1943). Thereafter, Brunschwig et al.(1943) and Bailey and Bailey (1943) reported the inducement of a persistent diabetic state in animals. This milestone was soon followed by a wealth of studies and dis-

Histochemical Studies of Various Organs in Rats with Experimental Congenital Diabetes

“…They reported that SD activity in the kidney, especially in the cortex, increased gradually after alloxan injection. However, this finding is in clear disagreement with Ihara's observations of the kidneys of rabbits with alloxan diabetes (Ihara, 1966a). In the present experiment too, an obvious increase in activity was seen in the proximal and distal tubules of rats with either spontaneous or alloxan diabetes.…”

“…This finding confirmed that of Ihara (1966a). Rudolph (1959) also demonstrated that ACPase and ALPase activities were clearly increased in the livers but decreased in the kidneys of rats with alloxan diabetes.…”

“…Moreover, only a few cells with normal activity were observed in the islets; they were not always in the peripheral zone and did not appear to be a-cells. The pancreas in rats with alloxan diabetes also showed a distinct reduction in islet cells as reported by Ihara (1966b) for rabbits with alloxan diabetes. He found that G-6-PD, ACPase, G-6-Pase and ATPase activities were significantly reduced in the a-cells in close parallel with those in the G-6-ease activity was noted by Midorikawa (1964) to be significantly increased in the islets of guinea pigs with steroid diabetes.…”

“…In the present experiment too, an obvious increase in activity was seen in the proximal and distal tubules of rats with either spontaneous or alloxan diabetes. Ihara (1966a) inferred that these findings represented an actual increase in Krebs cycle activity and signified an important compensatory function in the living body. In the diabetic kidney, it has been reported that glycogen infiltrates or is deposited in the thick limbs of Henle's loops and in the collecting tubules (Kashimura, 1958;Okamoto, 1951).…”

“…According to Rudolph (1959), the ATPase activity was distinctly increased in the hepatic lobules of rats with alloxan diabetes within six days after injection, while it decreased progressively in the renal tubules with the passage of time. Ihara's study of the liver and kidney in rabbits with alloxan diabetes (Ihara, 1966a) showed that the ATPase activity was slightly decreased in three days. This enzyme is responsible for the breakdown of ATP to ADP (adenosine diphosphate) with the release of free energy, a process utilized in muscle to supply the energy for contraction.…”