atrial-natriuretic-factor and Carcinoma

The diagnosis of primary aldosteronism (PA) is based on the finding of the combination of elevated urinary and/or plasma aldosterone and suppressed renin activity in patients with hypertension and hypokalemia. However, PA consists in a number of subsets, and diagnostic criteria for a correct identification of surgically remediable forms are of great interest. The methods and the results concerning our series of 113 patients with primary aldosteronism are presented in this review. Aldosterone producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) were the most frequent forms, 51% and 44% respectively. They had similar BP levels, but hypokalemia was most frequently found in APA. Urinary and upright plasma aldosterone were similar, but supine plasma aldosterone was lower in IHA. Plasma aldosterone response to upright posture and angiotensin II infusion was absent in most cases of APA and present in IHA, but occasionally renin-responsive adenoma were found. Captopril failed to decrease plasma aldosterone in most patients with APA, and in a subgroup of patients with IHA. Patients with adenoma had also higher values of the aldosterone precursor 18-OH-B, and of atrial natriuretic peptide (ANP), probably as a consequence of a greater degree of volume expansion. Among morphological studies, CT scan and adrenal radio-cholesterol scintiscan provided similar results (85% accuracy): adrenal vein catheterization clarified almost all the remaining cases. Among the subsets of PA, 3 familiar cases of dex-suppressible hyperaldosteronism were recognized, with characteristically high levels of aldo, 18-OH-B, 18-OH-cortisol and 18-oxo-cortisol, due to the genetic abnormalities of the 11-18 hydroxylase system.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenoma; Adrenal Cortex; Adrenal Cortex Neoplasms; Atrial Natriuretic Factor; Captopril; Carcinoma; Cytochrome P-450 CYP11B2; Cytochrome P-450 Enzyme System; Dexamethasone; Diagnostic Imaging; Humans; Hyperaldosteronism; Hyperplasia; Posture; Renin; Retrospective Studies; Steroid 11-beta-Hydroxylase

Human thyroid follicles and primary cell cultures derived from them demonstrated atrial natriuretic peptide (ANP)-like immunoreactivity when stained with a monoclonal antibody raised against rat alpha-ANP (ANP 1-28). In thyroid sections the staining was most intense in the tall cuboidal epithelium of small follicles. The intracellular distribution of immunoreactive (ir)-ANP in primary cultures of thyroid follicular cells consisted of discrete granules with a largely perinuclear distribution. The granule density increased with time in culture but was unaffected by exogenous ANP, suggesting an intrinsic synthesis of the immunoreactivity. Thyroid stimulating hormone (TSH; thyrotropin) failed to alter the distribution of ir-ANP after either short-term (6 h) or long-term (1-12 day) exposure. Epinephrine or norepinephrine treatment, however, caused a reduction in the ir-ANP granularity compared with controls in what might represent a stimulated release of the immunoreactivity. The present results suggest that the peptide ANP coexists with thyroid hormones in follicular cells and that the two endocrine activities might be under separate control mechanisms.

Topics: Antibodies, Monoclonal; Atrial Natriuretic Factor; Carcinoma; Cells, Cultured; Fluorescent Antibody Technique; Humans; Immunoenzyme Techniques; Thyroid Gland; Thyroid Neoplasms

A 62-year-old man arrived at our hospital with recurrence of Cushing's syndrome 14 years after successful surgery for adrenocortical carcinoma. Investigations demonstrated recurrence of a large tumor above the right adrenal area; it was found to be inoperable. The patient was treated initially with a new glucocorticoid antagonist, RU 486, and later with the adrenolytic agent mitotane (o,p'DDD). The latter achieved hypoadrenocorticism and a substantial reduction of tumor size. During the initial period, worsening hyperadrenocorticism resulted in a rise of atrial natriuretic factor and an inhibition of renin activity, consistent with an increase of cortisol and plasma volume. Changes in opposite direction were observed after treatment with mitotane.

Topics: Adrenal Gland Neoplasms; Atrial Natriuretic Factor; Carcinoma; Combined Modality Therapy; Cushing Syndrome; Humans; Male; Middle Aged; Mitotane; Neoplasm Recurrence, Local; Renin; Time Factors

Isolated fasciculata cells of rat adrenal cortex, when incubated with atrial natriuretic factor (ANF), stimulated the levels of cyclic GMP and corticosterone production in a concentration-dependent manner without a rise in the levels of cyclic AMP. The ANF-dependent elevation of cyclic GMP was rapid, with a detectable increment in 30 s. ANF also stimulated the particulate guanylate cyclase. These results not only indicate the coupling of cyclic GMP and corticosterone production with ANF signal, but also demonstrate that, like the ACTH signal, cyclic AMP is not the mediator of ANF-induced adrenocortical steroidogenesis.

Topics: Adrenal Cortex; Adrenal Cortex Neoplasms; Animals; Atrial Natriuretic Factor; Carcinoma; Corticosterone; Cyclic AMP; Cyclic GMP; Rats; Stimulation, Chemical