Application of Recapitulation Theory to Secretion of Atrial Natriuretic Peptide

1.从鳗鲡心房和心室分别分离出心房利钠肽（ANP）和心室利钠肽（VNP），并测定其氨基酸序列。我们还测定了鳗鱼VNP的cDNA序列。建立了鳗鱼心钠素（ANP）和血管紧张素原（VNP）的放射免疫分析方法，测定了鳗鱼血浆、心房、心室和脑组织中ANP和VNP的含量。心脏中ANP含量是VNP的3倍，而血浆中VNP含量是ANP的3倍.蛋白A-金免疫细胞化学显示大量分泌颗粒含ANP，但含VNP。.脑室内颗粒稀少.培养的鳗鱼心房肌细胞分泌少量的心钠素到培养基中，但储存在细胞中的量很大。培养的心室肌细胞分泌大量的VNP，但储存的VNP很少.基于这些结果，我们推测ANP主要在心房合成，储存在颗粒中，并在外源性刺激下分泌（调节途径），而大多数在心室合成的VNP很快分泌，而不储存在颗粒中（组成性途径）.为了证实这一假说，我们用标记的~（135）S-半胱氨酸进行了脉冲追踪实验<32>，以检测组织培养中鳗鱼心房和心室的ANP和VNP分泌率。采用北方印迹法检测心房和心室ANP和VNP mRNA的表达.在胎鼠中，心房和心室分别通过调节性途径和组成性途径分泌ANP，而成年哺乳动物心室不产生ANP。因此，从鳗鱼和胎鼠的数据说明，海克尔的生源定律，即。例如，“个体发生是生殖发生的重演”似乎适用于激素分泌方式。

1. We isolated atrial natriuretic peptide(ANP)and ventricular natriuretic peptide(VNP)from the eel atrium and ventricle, respectively and determined their amino acid seguences. We also determined cDNA sequence of eel VNP.2. We established specific radioimm unoassay systems for eel ANP and VNP, and measured the levels in eel plasma, atria, ventricles and brains. The heart contains 3-fold greater level of ANP than that of VNP, but the plasma level of VNP was 3-foldgreater than that of ANP.3. Protein A-goldimmunocytochemistry revealed many secretory granules which contain ANP, but VNP-containing. . granules in the ventricle was scarce.4. Eel atrial myocytes in culture secrete a small amount of ANP into the medium but the amount stored in the cell is large. Eelventricular myocytes in culture secrete a large amount of VNP but store little VNP.5. Based on these results, we hypothesized that ANP is principally synthesized in the atrium, stored in the granules, and secreted upon exogenous stimulus(regulatory pathway), whereas most of the VNP synthesezed in the ventricle is secreted soon without storage in the granules (constitutive pathway).6. In order to substantiate this hypotheses, we are now conducting a pulse-chase experiment using labeled ^<32>S-Cysteine to examine the rate of secreion of ANP and VNP from eel atrium and ventricle in tissue culture. We also examine the expression of mRNA of ANP and VNP in the eel atrium and ventricle using a Northern blot analysis.7. In the fetal rat, ANP is secreted from the atrium and ventricle viaregulatory pathway and constitutive pathway, respectively, although adult ventricles do not produce ANP in mammals. Thus, the data from eels and fetal rats illustrate that the Biogenic law of Haeckel, i. e., "Ontogeny is a recapitulation of phylogeny" appears to beapplicable to the mode of hormone secretion.