METABOLIC EFFECTS OF 2 REGIMENS OF GROWTH-HORMONE GIVEN BEFORE OPERATION IN PIGLETS

Objective: To clarify the effects of growth hormone (GH) given three d ays before and at the start of a standard abdominal operation or at th e start of the abdominal operation alone in piglets. Design: Randomise d experiment. Setting: University hospital, Norway Subjects: Twenty-fo ur piglets. Interventions: GH 24 IU was given intramuscularly for eith er three days before and on the morning of the operation or on the mor ning of a standard abdominal operation only (n = 8 in each group) A fu rther 8 piglets acted as untreated controls. Main outcome measures: Di ameter of fibres in the soleus and gastrocnemius muscles; urinary nitr ogen excretion; and fat and carbohydrate oxidation measured by indirec t calorimetry. Results: Nitrogen excretion was reduced (in the three d ays group the mean (SEM) was 30.8 (4.2) mg/kg, corresponding figures f rom the one day group and the controls were 37.6 (5.8) and 55.4 (3.1) mg/kg, respectively, p = 0.004). Fat oxidation increased (for the whol e period: p = 0.014) and carbohydrate oxidation decreased (p = 0.02) i n the one day group only. The diameter of type I muscle fibres was inc reased in both muscles (soleus, three day group, mean (SEM) 37.5(1.4) mu m compared with control, 30.4(0.6) mu m, p = 0.001, and gastrocnemi us, three day group 38.6(1.3) mu m compared with control, 30.8(1.4) mu m, p = 0.01>. Conclusions: Three days treatment with GH enhanced nitr ogen sparing and attenuated changes in fat and carbohydrate oxidation induced by one day treatment, but induced hypertrophy of type I muscle fibres.