Experimental diabetes in rats produced by parenteral administration of anti‐insulin serum

Abstract

We have shown (Armin, Grant & Wright, 1960) that the intravascular injection of single small doses of guinea-pig anti-insulin serum produces transient hyperglycaemia in the rat, rabbit and cat. This is thought to be due to the neutralization of endogenously secreted insulin by antibodies in the injected serum.We now show that when larger doses are administered to the conscious rat by intraperitoneal injection or prolonged intravenous infusion, anti-insulin serum produces a diabetic syndrome characterized amongst other things by hyperglycaemia, polyuria, glycosuria and ketonuria.The rat was chosen for these observations, rather than a larger and experimentally more suitable animal, because of the smaller volumes of serum required; potent anti-insulin serum was in short supply. Moreover, the rat is omnivorous and has already been much used for the study of experimental diabetes produced by alloxan and by pancreatectomy. METHODSDetails of the methods used for the production and assay of anti-insulin serum have already been reported (Armin et al. 1960). Briefly, such serum was obtained from guineapigs treated with an emulsion containing recrystallized bovine insulin and its potency was deduced from the hyperglycaemic effect which it evoked in rats on intravenous injection. Control serum was obtained from guinea-pigs treated similarly with insulin-free emulsion, and normal serum was derived from normal untreated guinea-pigs. The rats into which these sera were injected or infused in the present experiments were of an albino Wistar strain and were fed on a standard rat cake diet; unless otherwise stated, food and water were freely available.Anti-insulin serum. Four batches were used, their potencies being estimated to be such that 1 ml. neutralized approximately 2-3 u. Intraperitoneal injection. The rats (male, 190-205 g) were kept in warm cages. Serum (1-5 ml.) was injected through a fine short-bevelled needle into the peritoneal cavity at a point a little to the right of the mid line and half way between the xiphisternum and the

Effect of insulin and acute diabetes on plasma FFA and ketone bodies in the fasting rat

“…The method for measuring 'C in the Hg-acetone complex is described below. The remaining supernatant was transferred to another 16 X 150 mm tube and mixed with carrier acetoacetate (25 Amoles), K2Cr2O7 (15 complex containing 14C derived solely from jS-hydroxybutyrate-"C. The "C in total ketone bodies was determined, as described by Bates et al (18), in the sample used for enzymatic determination of acetoacetate and total ketone bodies; the aliquot was treated as described above for the determination of acetoacetate-"C to yield a Hg-acetone complex containing 'C derived from both acetoacetate and fi-hydroxybutyrate. The Hg-acetone complexes were washed with ice water, dissolved in 0.6 ml 2 N HCO and then mixed in screw-capped tubes with 15 ml of scintillation solution consisting of 24% Triton X-100 (Packard Instrument Co., Inc., Downers Grove, Ill.), 4% Liquifluor, and 72% toluene.…”

Direct observation of skeletal muscle blood vessels (rat cremaster)

“…Text-figure 2 shows the arrangement of motor driven syringes, Perspex taps and connecting pieces and polythene tubes (Armin & Grant, 1955;Armin, et al 1960) for conveying solutions to the muscle from either of two syringes without alteration of rate or significant interruption of flow. (Chambers & Zweifach, 1944 Under the green filter, the muscle is pale and is clearly seen to be arranged in two thin sheets of parallel bundles, the deeper sheet at an angle to the superficial.…”

“…Intravenous injections are made into the external jugular vein through a fine polythene tube (0.28 mm internal and 0-60 mm external diameter, PE 10) connected through a three way Perspex tap (Armin & Grant, 1955) and a wider polythene tube (PE 50) to a motor driven syringe with variable gears (Armin, Grant & Wright, 1960) containing Ringer's solution. Infusion at the rate of about 0 5 ml.fhr suffices to prevent clotting at the catheter tip.…”

Effects of Specific Antibodies on Tissue Cells

“…Anti-in-WISSLER sulin serum from guinea pigs immunized to purifi ed bovine insulin has re sulted in severe acute diabetes when inj ected into rats (197). A similar antiserum also produced hypoglycemia in dogs, a pig, and a Iamb (198).…”