Abstract
Abstract Injection of guinea pig anti-insulin serum into rats decreased the concentration of glycogen in the liver and increased the level of nonesterified fatty acid and glucose in the blood and the concentration of citrate in the heart. The uptake of glucose was reduced in hearts removed from antiserum-treated rats and perfused in vitro. Glucose production by perfused livers from rats treated with antiserum in vivo was increased as a result of accelerated glycogenolysis and gluconeogenesis. Urea production and K+ efflux were also increased. The rates of these processes could be reduced to or below control values by addition of insulin to the perfusion medium. Insulin added in vitro also decreased these processes and the loss of inorganic phosphate in livers from normal rats. Antiserum added to the medium perfusing normal hearts or livers was without effect except that it abolished the action of insulin. Administration of anti-insulin serum in vivo caused a progressive rise in the liver cyclic AMP concentration. Diabetes induced by alloxan also resulted in an increase in liver cyclic AMP, which was rapidly abolished by insulin treatment. Insulin added to the medium perfusing livers from normal or antiserum-treated rats caused a small decrease in liver cyclic AMP. Insulin antagonized the effects of epinephrine and glucagon on glucose output by the perfused liver and reduced the level of cyclic AMP in the presence of glucagon. The hypothesis is advanced that changes in cyclic AMP levels may be partly responsible for the alterations in liver metabolism caused by insulin and diabetes.
Highlights
Antiserum added to the medium perfusing normal hearts or livers was without effect except that it abolished the action of insulin
Insulin added in vitro abolished t.he increased glucose output due to AI-serum (Fig. 3), and this reduct.ion could again be partly ascribed to suppression of gluconeogenesis from lact.ate
These results indicate that insulin in vitro can lower the level of cyclic -DIP
Summary
Injection of guinea pig anti-insulin serum into rats decreased the concentration of glycogen in the liver and increased the level of nonesterified fatty acid and glucose in the blood and the concentration of citrate in the heart. Antiserum added to the medium perfusing normal hearts or livers was without effect except that it abolished the action of insulin. Insulin added to the medium perfusing livers from normal or antiserum-treated rats caused a small decrease in liver cyclic AMP. Samples of liver and heart were rapidly removed from animals anesthetized by intrapritoncal injection of 60 mg of sodium pentobarbibl per kg, and wrrc quick frozen at the temperature of liquid nitrogen [12] They were stored at -70” until analyzed. The sctrum nonest,erified fatt.y acid concentration was determined by t.he method of Dolt: [22], t.he hrart citrate concentration by the method of Stern [23], and t.hc liver inorganic phosphate concentrat.ion by the method of Wahler and Wollenberger [24]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
