Effect of a Pituitary Peptide on Liver Tissue Respiration 1

Summary The capacity of a pituitary peptide to stimulate the liver is further supported by tissue respiration studies. Peptide concentrates stimulate oxygen uptake of rat liver slices. The stimulating effect appears to be specific for the liver. The response of liver tissue was used to study the releasing mechanism of the peptide from hypophysis using Warburg's direct procedure. Cortisol (5 × 10−6 M) increased liver slice oxygen uptake only when pituitary tissue was included in the mixture. Epineph-rine (2 × 10−7 M) produced the same results only when pituitary and hypothalamus tissue were included. A possible relation between the effect of HTH, cortisol, and epinephrine on in vitro liver tissue metabolism and the in vivo release of vitamin-K-dependent coagulation factors was discussed.