Endocrine Abstracts

GH and IGF1 regulate plastic and synthetic intracellular lymphocytes process. We aimed to investigate the NAD- and NADP-dependent dehydrogenases activity in blood lymphocytes in patients with active acromegaly.

Thirty-three patients (11 men and 22 women, mean age 51.7±11.7 years), with the 6–10 years active phase duration of acromegaly, and 53 age- and gender matched healthy controls were determined the activity of NAD(P)-dependent dehydrogenases in blood lymphocytes. The activity of glycerol-3-phosphate dehydrogenase (Gly3PhD), glucose-6-phosphate dehydrogenase (Glu6PhD), lactate dehydrogenase, NADH-glutamate dehydrogenase (NADH-GDH), NADPH-glutamate dehydrogenase (NADPH-GDH), NAD(P)-isocitrate dehydrogenases, NAD(H)-malate dehydrogenases and glutathione reductase (GR) were measured using of biochemiluminescence method. The concentrations of somatotropin (GH) and IGF1 were measured by ELISA.

Chronic excess of GH and IGF1 in acromegaly associated with the high levels activity of Glu6PhD (P<0.001) and MDH (P<0.001), also, reduce the activity of GR (P<0.001), NADH-GDH (P=0.005) and NADPH-GDH (P<0.001). The correlation analysis revealed the reverse interaction between GH and NADH-GDH activity (r=−0.52, P=0.014) and between IGF1 and NADPH-GDH activity (r=−0.56, P=0.007).

Glu6PhD is the key enzyme of phosphogluconate pathway, MDH characterize the intensity of substrate flux on concluding steps of Krebs cycle. The increasing activity of GR in patients with acromegaly is the sign of glutathione-dependent antioxidant system insufficiency. Thus, the lymphocytes metabolism in acromegaly is remarkable for high level of plastic and aerobic respiration process, but the decreasing activity of glutathione-dependent antioxidant system.