Localisation and plasma release of atrial natriuretic peptide immunoreactivity (ANP-IR) in the rat

Atrial natriuretic peptide: what is the excitement all about?

“…In the rat, concentrations are very approximately 50 nmol/g of wet tissue (Christofides et al 1984;Tanaka, Misono & Inagami, 1984). Both bioassay (Gutkowska et al 19846) and radioimmunoassay results indicate that the right atrial ANP con¬ centration is greater than that of the left atrium of the rat, although the functional significance of this remains to be elucidated.…”

“…It nevertheless seems likely that the form is the most abundant atrial storage form in man in vivo and that the varying ratios of other smaller forms reported are due to post-mortem degradation -a reflection of the difficulty of obtaining fresh human tissue. In both rat and human plasma, in contrast, the form of ANP appears to be the major circulating form (Christofides et al 1984;Gutkowska, Thibault, Januszewicz et al 19846;Gutkowska, Bourassa, Roy et al 1985 ). Very recently sufficient ANP has been purified from rat plasma to allow amino acid sequence analysis to determine its precise structure.…”

“…The reports of the release of ANP into the circula¬ tion in vivo in response to intravascular (Christofides et al 1984) or extracellular fluid volume expansion have provided important evidence to support the putative role of ANP as a circulating natriuretic hormone. Much more recently it has been shown that the intravenous infusion of physiological saline solution produces plasma release of a-hANP in man (Sagnella, Markandu, Shore & MacGregor, 1985a;Anderson, Donckier, McKenna et al 1986 ;Richards, Cleland, Tonolo et al 1986).…”

“…In rat, pig and ox atria the majority of the ANPlike immunoreactivity exists as the high molecular weight ( ) form (Christofides, Anderson, Vinas et al 1984;Nakao, Sugawara, Morii et al 1984;Miyata, Kangawa, Toshimori et al 1985). In human atria the , ß and forms have been found in varying ratios (Miyata et al 1985).…”

Urodilatin: A Natriuretic Peptide of Renal Origin

“…These forms were purified and their amino acid sequences were determined (39). The larger form, yANF, consists of 126 amino acids, and it was found to be the precursor of a-ANF, which arises from the 28 amino acids of the carboxy terminal end (15,26,45). In humans, y-ANF is derived from a longer preprohormone of 151 amino acids (53).…”