Effects of Growth Hormone and Estrogen on Rat Angiotensinogen Quantified by an Enzyme Linked Immunosorbent Assay

An enzyme linked immunosorbent assay for rat angiotensinogen was developed based on one monoclonal antibody with high affinity for angiotensinogen and des-angiotensin 1–angiotensinogen and rabbit polyclonal antibodies for angiotensinogen was developed. Serum levels of angiotensinogen were lower in female than in male rats but increased significantly after hypophysectomy. Estrogen substitution after hypophysectomy had no further stimulatory or inhibitory influence. In hypophysectomized animals continuous and intermittent growth hormone administration had clearly different effects. The results indicate that the sexually dimorphic secretion of growth hormone is involved in the regulation of circulating angiotensinogen concentrations in the rat.