Effects of oestrogen and human growth hormone on pregnancy-associated plasma proteins in the rat

Abstract

The serum concentrations of pregnancy-associated murine protein-1 (PAMP-1), acute phase alpha 2-macroglobulin, albumin, transferrin, and complement factor 3(C3) were followed in male rats during continuous infusions of oestradiol-17 beta and human growth hormone. Three different patterns of protein response could be distinguished. A distinct acute phase response without any additive influence of the given hormones was recorded for alpha 2-macroglobulin, whereas the levels of albumin, transferrin and C3 were virtually unaffected throughout the experiment. Growth hormone gave a rapid and pronounced increase of PAMP-1 levels, whereas the response to oestradiol of this 'steroid-sensitive' protein was significantly weaker and delayed. It is suggested that the apparent oestrogenic influence on certain pregnancy-associated plasma proteins is mediated via growth hormone.