Atrial natriuretic hormone in lower vertebrates.

点击翻译按钮获取中文摘要

The present investigation was undertaken in order to obtain more information on the atrial natriuretic peptide (ANP) in lower vertebrates.I. On the ANP-like immunoreactive material (ir-ANP) in fish. 1) Cardiocytes from six species of freshwater (FW and five species of seawater (SW) teleosts, and one elasmobranch were investigatied immunohistochemically immunocytochemically and ultrastructurally, and the plasma ANP activity of these fish was measured by RIA. FW fish performed both synthesis and release of ANP-like material more actively than SW fish. 2) Distribution of ANP-like immunoreactivity in the carp atrium and ventricle was studied by the avidin-biotin complex method, the protein A-gold technigue, gel chromatography and RIA. The ANP-like material is contained in the secretory granules in the atrial and ventricular cardiocytes, but the secretory activity of the ventricular cardiocytes is lower than the atrial cardiocytes. Main component of the ANP-like material in the atrial and ventricular tissue would be gamma-type ANP. 3) FW-acclimatized eels were transferred to SW, and after varying time their atrium and ventricle were studied immunohistochemically and immunocytochemically. The ir-ANP was found delicately controlled in its synthesi and release in response to changes in environmental salt concentration in this euryhaline fish.II. on ir-ANP in anuran Bufo. 1) The ir-ANP in toads at various developmental stages was studied, and two different-sized granules, both containing ir-ANP, were noticed cardiocytes. 2) Spring (breeding) and summer (non-breeding) toads were compared, and much larger amount of ir-ANP was found in the former, thus indicating that this peptide is related to their temporal aquatic life.