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Biomedical subjects

M Naruse

Publications and source records attributed to M Naruse.

At least 217 records · Page 12Linked to original sources

[A case of cystadenocarcinoma developing from an ovary autografted to the abdominal wall].

A 73-year-old woman developed an abdominal tumor. We performed tumor resection. The tumor, located between the fascia and peritoneum, was removed completely. The histological finding was cystadenocarcinoma. Thirty-eight years earlier she had undergone total hysterectomy and bilateral oophorectomy because of abnormal genital bleeding. At that time, her own ovary had been transplanted to the abdominal wall. We diagnosed this tumor as having developed from the autografted ovary. The complication of ovarian autografting is cystic degeneration. This complication is rare in Japan. Moreover, malignant change is extremely unusual in ovarian autografting.

Abdominal Muscles↗

Retroperitoneal bleeding due to a ruptured aneurysm of the middle colic artery.

In a 51-year-old man the middle colic artery ruptured. The patient had abdominal pain for several days, and then suddenly, a considerable intraperitoneal bleeding occurred. The aneurysm was extirpated and in the postoperative angiogram, numerous aneurysms were detected in the colic artery. Splanchnic artery aneurysm mainly occurs in renal artery, splenic artery and hepatic artery, but rarely in the mesenteric artery. The pathogenesis of mesenteric artery aneurysms is usually mycotic false aneurysm from prior aortic endoarteritis. In the present case, the etiology of the aneurysm was not confirmed.

Aneurysm↗

Effect of metoclopramide in plasma vasopressin in man.

The effect of metoclopramide, a dopamine blocker, on arginine vasopressin (AVP) secretion was investigated in normal males. After a bolus injection of metoclopramide (10 mg), all subjects (n = 7) demonstrated an increase of 80.3% (from 0.71 +/- 0.12 (Mean +/- S.E.) to 1.28 +/- 0.24 pg/ml, P less than 0.005) in plasma AVP at 15 min. In controls (n = 7) plasma AVP levels did not change after saline injection (2 ml). Because plasma osmolality and blood pressure did not change, the elevation of plasma AVP levels induced by treatment with metoclopramide may be due to its central effect as a dopamine inhibitor. Although plasma AVP levels increased again at 90 and 120 min after a bolus injection of metoclopramide, accompanying falls in blood pressure (4-5%) make the interpretation concerning the contribution of dopamine to AVP secretion in a late phase uncertain. In summary, plasma AVP levels were shown to be significantly increased by a metoclopramide bolus, suggesting that AVP secretion is under tonic inhibition by dopamine.

Adult↗

In vivo evidence of cortisol secretion by aldosterone-producing adenomas.

This study was done to confirm that aldosterone-producing adenomas secrete cortisol in vivo. Plasma cortisol and aldosterone concentrations were measured in samples obtained by selective adrenal-vein sampling in 8 patients with primary aldosteronism due to unilateral adenoma. All cases revealed higher adrenal-vein plasma cortisol concentrations on the adenoma side than the opposite, irrespective of adenoma location. These concentrations correlated significantly with plasma aldosterone concentrations (r = 0.972, P less than 0.001) in effluents from the adenoma side, but not from the opposite. Plasma concentrations also correlated significantly with estimated adenoma volume (r = 0.918, P less than 0.05). These findings strongly suggest that aldosterone-producing adenomas secrete cortisol in vivo. In a second study, we used metyrapone to test 6 patients with adenomas. Their responsiveness to cortisol and corticotrophin was found to be the same as that in normal subjects, suggesting that adenoma-secreted cortisol did not disturb the relationship between corticotrophin and cortisol. We thus concluded that cortisol is secreted concomitantly with aldosterone from aldosterone-producing adenomas under corticotrophin influence.

Adenoma↗

Gonadotropin-dependent renin in the rat testes.

Using specific anti-rat renal renin antibody, the presence of renin in the rat testis was demonstrated by biochemical determination of renin activity. There was no correlation between testicular and plasma renin activity, indicating independent control of testicular and plasma renin levels. Since specific immunohistochemical staining for renin had been observed exclusively in Leydig cells, the effects of hypophysectomy and gonadotropin treatment on the testicular renin were investigated. After hypophysectomy, renin level in the testis decreased significantly, whereas plasma renin was slightly increased. In contrast, testicular renin had remarkably increased through gonadotropin treatment. The results indicate the presence of gonadotropin-dependent renin in the Leydig cells, and suggest a role for it in regulating testicular functions.

Animals↗

Endocrine characterization of the adrenal adenomas in a case of primary aldosteronism.

A 48-year-old man with typical clinical and biochemical features of primary aldosteronism was revealed on operation to have two adrenocortical adenomas in the left gland. An ACTH-dependent pattern of aldosterone secretion was demonstrated in terms of the parallel circadian rhythm of aldosterone with cortisol and the exaggerated response to ACTH but not to angiotensin II. Aldosterone and cyclic AMP release in vitro was studied using collagenase-dispersed cells of each adenoma. Not only the large adenoma but the small one showed basal and ACTH-stimulated releases of aldosterone greater than those by the adjacent tissue. In response to angiotensin II and potassium, the small adenoma showed a larger maximum increment of aldosterone than the large adenoma. This difference in endocrine features of the two adenomas suggests a possible transformation in their nature during development. An exaggerated cyclic AMP release by the adenomas in response to ACTH in vitro suggested the possible role of increased adenylate-cyclase activity in the hyperresponse of aldosterone to ACTH in this case.

Adenoma↗

The subcellular distribution of renin in hog anterior pituitary.

Renin in hog anterior pituitary was found to be located principally in the particulate fractions. Density gradient centrifugation of the granular fraction revealed a discrete band of renin activity distinct from lysosomal and mitochondrial markers. This band has a density similar to that of known kidney renin secretory granules and may be due to renin secretory or storage granules in the anterior pituitary.

Animals↗

Renin exists in human adrenal tissue.

Readily detectable levels of renin activity were demonstrated in human adrenal tissues. This activity was inhibited by specific antibody raised against pure renin, indicating that it was not due to the nonspecific action of proteases. The renin activity was predominantly in the cortex rather than in the medulla of the adrenal. An adrenal gland that was surgically removed from a patient with Cushing's disease and had high renin activity was used for further characterization of the enzyme. It shared many biochemical features with kidney renin, such as molecular weight, isoelectric point, glycoprotein nature, optimum pH of enzyme activity, affinity to pepstatin, and the presence of trypsin-activatable inactive renin. The lack of correlation between PRA and the adrenal renin, and the particulate localization of the subcellular distribution of adrenal renin suggested its local origin rather than contamination or contribution of the plasma enzyme.

Adrenal Glands↗

Local generation of angiotensin in the kidney and in tissue culture.

The renin-angiotensin system is an exception among the various peptide hormone producing mechanisms in that it is an extracellular system. It was not clear whether renin in tissues other than kidney participates in the extracellular system or an intracellular mechanism. We examined the possibility of intracellular formation of angiotensin II in these tissues by using cloned, renin containing cells in culture as models. Neuroblastoma cells, pheochromocytoma cells, adrenal cortical cells and juxtaglomerular cells were shown to contain renin, angiotensin I and angiotensin II. Presence of angiotensin I converting enzyme was also demonstrated in some cell lines examined. Even juxtaglomerular cells in the intact kidney were shown to contain angiotensin I and angiotensin II by immunohistochemical technique. These findings indicate an intracellular mechanism of angiotensin II formation in various tissues and suggest that angiotensin II may have local paracrine functions.

Adrenal Cortex↗

[Chronic encapsulating fibrous peritonitis induced by carcinoma of the pancreas].

A 70-year-old man was admitted complaining of dull pain in the epigastrium and umbilical region. ERCP revealed a carcinoma of the pancreas; cytological examination of the pancreatic juice and ascites showed no tumor cells. Diagnostic laparotomy was performed for lasting abdominal pain and fever. Exploration revealed ascites and adhesions. The small and large intestine were covered with a gray-white membranous substance. A large tumor invading the retroperitoneal space was seen in the head of the pancreas. Histological examination of the membranous substance showed hyalinizing fibrinoid tissue; the tumor contained carcinoma cells of the pancreas. We posit that the tumor disturbed the flow of the portal vein and lymphatic vessels, leading to the patient's clinical symptoms.

Aged↗

Markedly elevated specific renin levels in the adrenal in genetically hypertensive rats.

The specific renin (EC 3.4.99.19) activity in the adrenal of spontaneously hypertensive rats was determined by a method that is capable of distinguishing renin from nonspecific renin-like activity of proteases by using specific antibody to renin. The renin level in the adrenals of adult spontaneously hypertensive rats with established hypertension was found to be 6-8 times as high as that of the normotensive control Wistar-Kyoto strain. The large difference in the adrenal renin level was observed even in 3-wk-old rats in which hypertension has not yet developed. The adrenal renin level was increased by bilateral nephrectomy in both the hypertensive and normotensive strains. A larger quantity of renin was found in the adrenal cortex than in the medulla, and the difference between the hypertensive strain and the normotensive strain was more prominent in the cortex than in the medulla. These results suggest possible involvement of adrenal renin in the development and in the early maintenance phase of hypertension in this animal mode of human essential hypertension by affecting the adrenocortical or adrenomedullary activity, or both.

Adrenal Cortex↗

Totally inactive renin zymogen and different forms of active renin in hog brain tissues.

The nature of the activable form of renin in the kidney and other tissues has not been clear. Its identification and isolation from kidney have been hampered by rapid activation due to high levels of proteases. Using a pepstatin-Sepharose column, which distinguishes inactive renin from the active enzyme, evidence was obtained for the presence of a totally inactive zymogenic precursor of renin in the pituitary, pineal, and other regions of hog brain. The precursor has an approximate molecular weight of 50,000 and conversion to the active enzyme causes reduction in molecular weight to 43,000. Conversion of this active enzyme to an active but high molecular weight form (60,000) was also observed when the pituitary extract was treated with thiol-blocking reagents. This result was interpreted to indicate the presence of a binding protein. This study has demonstrated that inactive renin zymogen is different from so-called active big renin, which is a complex of active renin and the binding protein.

Animals↗