Effects of Gonadotrophins, Dibutyryl Cyclic AMP and Prostaglanclin E2 on Amino Acid Transport and Glycolysis in Isolated Rat Corpora Lutea

Corpora lutea (CL) were isolated by free hand dissection from ovaries of 34–39 day‐old Sprague‐Dawley rats injected with 10 IU Pregnant Mare's Serum gonadotropin (PMSG) when 30 days old leacling to ovulation in the morning of day 33. Injection of luteinizing hormone (LH) to rats 2 h before removal of the ovaries stimulated the in vitro uptake of the non‐utilizable amino acids, a‐aminoisobutyric acid (AIB‐14C) and 1‐amino‐cyclopentane‐carboxylic acid (cycloleucine‐3H) by 3‐day‐old CL during a subsequent incubation in Krebs bicarbonate buffer. Prolactin and FSH were without effects. Addition of LH directly to the incubation medium did not stimulate amino acid uptake of the isolated CL, while addition of dibutyryl cyclic AMP (dbcAMP) enhanced this uptake. Glycolysis was estimated by determination of lactic acid accumulation in die incubation medium. When LH was injected to the animals 2 h before sacrifice, lactic acid production of 3‐day‐old CL was stimulated during a subsequent incubation period. Addition of LH in vitro caused a slight increase in the rate of glycolysis, and dbcAMP and prostaglanclin E2 (PGE2) also exhibited stimulatory effects on lactic acid production by the incubated CL. In a few experiments rats with 7‐day‐oId CL were given injections of LH. While amino acid uptake was not stimulated in these old CL, LH did enhance the rate of glycolysis in these CL.