Growth hormone-binding proteins: state of the art

Abstract

The discovery of growth hormone-binding proteins (GHBP) in the mid-1980s has provided considerable impetus to the elucidation of growth hormone (GH) action. The unexpected finding of a circulating GH 'receptor' \p=n-\the high-affinity GHBP \p=n-\in serum has facilitated assessment of GH receptor status in humans through a simple venipuncture, whereas previously GH receptors could only be reliably quantified in liver. Although it remains to be rigorously proven that the GHBP level in serum reflects tissue GH receptor concentrations, there is mounting evidence that this is indeed the case. Comprehensive reviews of this field have recently appeared (Baumann 1993, Mercado & Baumann 1993; the present commentary will therefore give essential background and primarily focus on conceptual issues and areas where knowledge or understanding is incomplete.

Consequences of maternal undernutrition for fetal and postnatal hepatic insulin-like growth factor-I, growth hormone receptor and growth hormone binding protein gene regulation in the rat

“…Regulation of the GH receptor (GHR) is also an important mechanism of control within the somatotrophic axis. The GH binding protein (GHBP), a second product of the GHR gene corresponding to the extracellular domain of the GHR, may also regulate GH action both at an endocrine and at a local level (Baumann 1994). In rodents, the liver is the primary source of GHBP in plasma, although most non-hepatic tissues also express GHBP mRNA (Tiong & Herington 1991).…”

Nutritional and Endocrine-Metabolic Aberrations in Women with Functional Hypothalamic Amenorrhea1

“…IGFBP-1 is a potent inhibitor of the insulin-like activity of IGF-I (42); thus, the reduction in the ratio of IGF-I/IGFBP-1 in FHA may act as an energy-conserving strategy by minimizing the hypoglycemic action of IGF-I. GHBP concentrations, a reflection of the extracellular domain of hepatic GH receptors (43), were reduced 40% in FHA, consistent with more severe hypometabolic states, such as anorexia nervosa (34,44) and fasting (43).…”

Growth hormone and growth hormone gene of the American mink (Neovison vison) – the current state of knowledge of one of the key hormones in one of the most intensively economically exploited species

“…This binding is reversible, and the growth hormone in the form of the GH-GHBP complex loses the ability to bind with the specific trans-membrane receptor, what results in the functional inactivation of the hormone (Baumann, 2009). On the other hand, the said complex protects the growth hormone from degradation and secretion from the system (Baumann, 1994).…”