Early Investigations: Characterizations of the Circulating Growth Hormone

Identification of patients who resembled GH deficiency, both clinically (dwarfism, obesity) and biochemically (tendency for hypoglycemia) (Fig. 2.1), and high FFA (Fig. 2.2), but who had abnormally high overnight fasting serum concentrations of circulating hGH (Laron and Mannheimer 1966; Laron et al. 1968; Laron 1984) (Fig. 2.3), led us to conclude that we had discovered a new disease entity (Laron et al. 1966). To explain the high serum human growth hormone (hGH), we considered two possibilities: (a) an abnormal hGH molecule or (b) a defect in the hGH receptors (Laron et al. 1966), leading to end organ resistance (Laron et al. 1971, 1980). As the serum hGH levels in the same patient varied on different days, as seen in Fig. 2.3, possibly due to not complete fasting, previous exercise, stress, or physiological fluctuations, we investigated the diurnal secretion and regulation of GH secretion in these patients.