Effects of growth hormone treatment on red cell plasma membrane fatty acidconstituents in hypopituitary adults

The effects of replacement with recombinant human GN (hGH) on red cell plas ma membrane fatty acid and cholesterol constituents were assessed in nine a dult patients with growth hormone deficiency. They were treated with hGH in a dose of 0.125 U.kg(-1).wk(-1) for four weeks and at 0.25 U.kg(-1).wk(-1) thereafter for an overall mean duration 13.5+/-3.9 months (mean +/-SD). Th e relative proportions of the various phospholipid fatty acid constituents and the proportion of cholesterol in the phospholipid bilayer were assayed every six months. At the end of the study, the percentage of arachadonic ac id (20:4) in membrane phospholipid was found to rise by an average of 3.7% (P<0.05) and there appeared to be a nonsignificant trend showing an increas e in highly unsaturated fatty acids, namely linoleate (18:2) and gamma lino lenic acid (18:3) and a corresponding decrease in unsaturated fatty acids, namely palmitate (16:0) and stearate (18:0) and monounsaturated fatty acids such as palmitoleic acid (16.1), oleic acid (18:1) and oleic acid isomer ( 18:1 iso). In addition, the proportion of cholesterol in the plasma membran e i.e. the cholesterol/phospholipid ratio was found to decrease by 0.84% (P < 0.05). There was a significant increase in HbAlc from 4.85+/-0.51 to 4.94 +/-0.45% (P<0.01) by the end of the study.