angiotensinogen and Adenoma

Topics: 11-beta-Hydroxysteroid Dehydrogenases; ACTH Syndrome, Ectopic; Adenoma; Adrenal Gland Neoplasms; Adrenocorticotropic Hormone; Angiotensinogen; Cushing Syndrome; Diagnosis, Differential; Glucocorticoids; Humans; Hydrocortisone; Hypertension; Nitric Oxide; Pituitary Neoplasms; Receptor, Angiotensin, Type 1; Sympathetic Nervous System

Renin, angiotensinogen, and converting enzyme were detected in 10 normal human pituitary glands by immunohistochemical techniques. Renin was stained by polyclonal and monoclonal antibodies directed against human renin, and an antibody directed against the renin prosegment revealed the presence of prorenin. Immunoreactive angiotensinogen and angiotensin I-converting enzyme were found in the same cells as renin. Using serial sections and double immunohistochemical labeling with a PRL antiserum, all of the proteins of the renin-angiotensin system appeared to be localized within the lactotroph cells, and no component of the renin system was detected in any of the other pituitary cells. Renin, angiotensinogen, and angiotensin I-converting enzyme also were found in 6 PRL-secreting adenomas as well as in a mixed PRL/GH-secreting adenoma. The renin content of a PRL adenoma was about 1/100th that of a normal kidney. Renin activity could be blocked by an anticatalytic human renin antibody. No renin, angioten-sinogen, or angiotensin I-converting enzyme was found in 6 GH-secreting adenomas, 1 corticotroph adenoma, or 10 nonsecreting pituitary adenomas. The colocalization of proteins of the renin-angiotensin system suggests production of angiotensin II within the lactotroph cells and favors the hypothesis of a paracrine action of this peptide.

Topics: Adenoma; Adolescent; Adult; Aged; Angiotensinogen; Angiotensins; Child; Child, Preschool; Female; Fluorescent Antibody Technique; Histocytochemistry; Humans; Immunoenzyme Techniques; Infant; Male; Middle Aged; Peptidyl-Dipeptidase A; Pituitary Gland, Anterior; Pituitary Neoplasms; Prolactin; Renin

The mechanisms causing high blood pressure in patients with Cushing's syndrome were investigated by measurements of humoral factors and pharmacological maneuvers. Twelve patients with adrenal adenomas were studied. The mean systolic and diastolic pressures of the patients were 171 +/- 28 and 109 +/- 15 mm Hg (+/- SEM), respectively, which were significantly higher than those of normal subjects. PRA, plasma renin concentration, plasma renin substrate, plasma cortisol, plasma aldosterone, urinary kallikrein, and urinary prostaglandin E2 were measured as the humoral factors. PC values were markedly elevated in patients with Cushing's syndrome. Among the components of the renin-angiotensin system, only plasma renin substrate was increased. Urinary kallikrein and prostaglandin E2 were decreased in patients with Cushing's syndrome. Oral administration of captopril lowered blood pressure, but infusion of an angiotensin II analog did not. Furthermore, the pressor responses to infusion of both norepinephrine and angiotensin II were increased. We conclude that blood pressure is elevated in patients with Cushing's syndrome because they have enhanced pressor responses to vasoactive substances, suppression of depressor systems, and some abnormalities of the renin-angiotensin system.

Topics: Adenoma; Adrenal Gland Neoplasms; Adult; Aged; Aldosterone; Angiotensin II; Angiotensinogen; Captopril; Cushing Syndrome; Dinoprostone; Female; Humans; Hydrocortisone; Hypertension; Kallikreins; Male; Middle Aged; Norepinephrine; Prostaglandins E; Renin; Renin-Angiotensin System

Topics: 18-Hydroxydesoxycorticosterone; Adenoma; Adolescent; Adrenal Cortex Neoplasms; Adrenal Glands; Adult; Aged; Aging; Angiotensin II; Angiotensinogen; Carbon Dioxide; Corticosterone; Desoxycorticosterone; Female; Humans; Hyperaldosteronism; Hypertension; Kidney; Kidney Diseases; Male; Middle Aged; Potassium; Renin; Sodium; Urea; Vascular Diseases

The influence of pH and angiotensinase inhibitors on the in vitro generation of angiotensin I during PRA measurements has been investigated. PRA values obtained at pH 5.7 are higher than those obtained at pH 7.4. At pH 5.7, values obtained using diisopropylfluorophosphate (DRP 9 mM) as an angiotensinase inhibitor are higher than values obtained with a mixture of dimercaprol (BAL, 1.6 mM) and hydroxyquinoline (8-OHQ, 3 to 4 mM). Since the two methods for inhibiting angiotensinase are completely and equally efficient, it is suggested that these inhibitors might interfere with the renin angiotensinogen reaction. Significant correlations are observed between the PRA values obtained by the different methods which have been studied. Using an incubation pH of 5.7, and BAL and 8-OH quinoline as angiotensinase inhibitors, the distribution of PRA values in a population of 124 hospitalized hypertensive patients ingesting a normal sodium diet had been studied, and it has been demonstrated that the sensitivity of this method of measurement can detect small changes in PRA in patients with low renin activity.

Topics: Adenoma; Adrenal Gland Neoplasms; Adult; Angiotensin II; Angiotensinogen; Dimercaprol; Humans; Hydrogen-Ion Concentration; Hypertension; Isoflurophate; Methods; Middle Aged; Oxyquinoline; Posture; Protease Inhibitors; Radioimmunoassay; Renin; Time Factors