El corazón endocrino y el proceso inflamatorio / [The endocrine heart and inflammation].

The endocrine heart produces the polypeptide hormones Atrial Natriuretic Factor (ANF or ANP) and Brain Natriuretic Peptide (BNP). Through the peripheral actions of these hormones the heart contributes to the regulation of the cardiac preload and afterload. More recently, new functions for these hormones have been described including the modulation of the immune response. Plasma levels of BNP but not those of ANF, increase following an acute rejection episode of a cardiac allotransplant but return to levels pre-rejection with successful treatment. This observation constitutes the first observation leading to characterizing the interactions of BNP with the immune response. Several other pathologies with an inflammatory component are now known to be associated with an increase in the production of BNP. Such an increase is due to an increase in the transcriptional activity of the BNP gene induced by cytokines and related substances. In vitro investigations have shown that an increase in BNP directly modulates immunological activity. Inflammation and hemodynamic changes co-exist in several cardiovascular diseases and therefore it may be beneficial to measure circulating levels of both ANF and BNP as biomarkers of changes in intravascular volume and of changes in intravascular volume plus inflammation, respectively. Changes in plasma ANF, that are relatively larger than those of BNP, might be an indication of hemodynamic deterioration while important changes in circulating BNP could indicate a worsening of the inflammatory process.

Presence and release of immunoreactive atrial natriuretic peptide (ANP) in Bufo arenarum spermatozoa after HCG treatment

Atrial natriuretic peptide (ANP)-like immunoreactivity has been demonstrated in mature spermatozoa of Bufo arenarum. However, after spermiation induced by Gonadotropin Releasing Hormone (GnRH), no ANP immunoreactivity was detected in testicular spermatozoa. Recently, the presence of GnRH and GnRH receptors in amphibian testes has been demonstrated. To clarify if the loss of ANP-like immunoreactivity in spermatozoa is a direct effect of GnRH or pituitary gonadotropins, a study on Bufo arenarum adult males, has been performed. The in vivo treatment with Human Chorionic Gonadotropin (HCG) induced spermiation and loss of ANP-like immunoreactivity. The in vitro treatment with HCG showed the same results. However, in vitro GnRH treatment failed to cause spermiation and loss of ANP-like immunoreactivity. The present results indicate that ANP from mature spermatozoa is regulated via gonadotropic hormones and may be involved in the spermiation process.

La adrenalectomía reduce la actividad de la guanilata ciclasa estimulada por el péptido atrial natriurético en el núcleo paraventricular de ratas / The adrenalinectomy reduce the cyclase guanylate activity stimulate by the natriuretic atrial peptide in the rats paraventricular nucleus

El péptido atrial natriurético (ANP por sus siglas en inglés) o un análogo, la Atriopeptina III (Pl 058) estimulan la formación de cGMP en la fracción de membrana del bulbo olfatorio de la rata, en la eminencia mediana y en el núcleo paraventricular, de manera dosis-dependiente. El efecto del análogo Atriopeptina III fue de un 20-40 por ciento mayor que el del ANP. Se investigó la adrenalectomía bilateral, con o sin reemplazo mineral o glucocorticoide, en la formación de cGMP estimulada por el ANP en el núcleo paraventricular de ratas. 11 días después de realizada la adrenalectomía bilateral de la producción inducida de cGMP. Este efecto fue prevenido mediante la administración de deoxicorticosterona, no así con la administración de dexametasona. Nuestros resultados apoyan aún más la presencia de receptores pareados de ANP con guanilata ciclasa localizados en lugares específicos del cerebro. Esto proporciona evidencia que sugiere que los sitios de enlace del ANP con la guanilata ciclasa en el PVN son susceptibles a cambios reguladores de la activación inducida de la adrenalectomía del sistema hipotálamo-hipofisoadrenocortical