ALBUMIN SYNTHESIS AND BONE-COLLAGEN FORMATION IN HUMAN IMMUNODEFICIENCY VIRUS-POSITIVE SUBJECTS - DIFFERENTIAL-EFFECTS OF GROWTH-HORMONE ADMINISTRATION

Loss of lean tissue often accompanies human immunodeficiency virus (HI V) infection. Exogenous human recombinant GH (hrGH) has been shown to be beneficial in reversing this wasting. However, catabolic effects of hrGH on muscle protein metabolism have also been reported. Therefore, the responsiveness of other GH-sensitive tissues, including bone form ation and albumin synthesis, has been examined. Anabolic activity in b one, from serum levels of carboxy-terminal propeptide of type I collag en, was stimulated by 2 weeks of hrGH in controls (56 +/- 15%, P = 0.0 02), patients with asymptomatic HIV(24 +/- 10%, not significant), pati ents with AIDS (47 +/- 7%, P < 0.001), and patients with AIDS and >10% weight loss (21 +/- 12%, P = 0.02). Albumin synthesis, determined fro m the incorporation of L-[H-2(5)] phenylalanine, was increased in resp onse to hrGH in controls (23 +/- 7%, P < 0.05), HIV+ subjects (39 +/- 16%,P < 0.05), and patients with AIDS (25 +/- 7%, P < 0.01). Patients with AIDS and weight loss, however, did not increase albumin synthesis (-0.6 +/- 12%) in response to hrGH. The results indicate variable ana bolic responses to hrGH. Bone collagen synthesis remained sensitive to hrGH, whereas, the anabolic action of hrGH on the synthesis of albumi n diminished with severity of disease. However unlike muscle protein s ynthesis, albumin synthesis was not depressed below basal levels by hr GH.