Synthesis of corticosterone in the vascular wall

Extra-adrenal steroid 21-hydroxylation and 11 beta-hydroxylation occur in a variety of human tissues. This study was undertaken to determine whether the rat mesenteric artery produces corticosterone and to demonstrate the CYP11B1 mRNA in the vascular tissue. Isolated rat mesenteric arteries were perfused with Krebs-Ringer solution for 4 h. The perfusate was collected and chromatographed in a reverse-phase HPLC system. The fraction corresponding to synthetic corticosterone was collected and analyzed by mass spectrometry. The concentration of corticosterone in the perfusate from the adrenalectomized rats was measured using radioimmunoassay after separation with the HPLC system. The mass spectra of synthetic corticosterone was identical with corticosterone isolated from the perfusate of the rat mesenteric arteries. The radioactive peak of corticosterone was detected in the perfusate after perfusing the mesenteric artery with Krebs-Ringer solution containing [14C]-pregnenolone. The expression of CYP11B1, 11B2, and 11A mRNA was detected in the mesenteric artery using a RT-PCR. The production of corticosterone in the vascular wall was increased in the adrenalectomized rats compared with that of the controls. This study shows that the rat mesenteric artery produces corticosterone, and the corticosterone synthase is existed in the vasculature.

[Evaluation of the effective use of the "health notebook"]

Since 1983, with the institution of the "Health Service Law for the Aged", the "health notebook" has been issued to people aged 40 years and over in order to aid in management of their health. Few people actually fill their health data in notebook by themselves. In order to develop effective use of the health notebook by residents and health professionals, the uses of the health notebooks by residents aged 40 years and over, public health nurses, and physicians were investigated. Three hundred and fifty four residents aged 40 and over, 41 public health nurses, and 18 physicians were studied in 1990, in Yamagata city. A majority of residents took their health notebooks with them to health consultations, and public health nurses used the notebooks to provide advice to them. Public health nurses effectively issued the health notebooks to residents using occasions where residents gathered. Some physicians reported that health notebooks were useful for motivating the people to maintain their health, while others preferred using a health card media. When comparing the health notebooks to the maternity passbooks, health notebooks need to be more easily utilized by users for recording information, and their value should be effectively explained to them. Furthermore, in order to promote self-care behaviors, greater use of health notebooks by all health professionals in indicated.

Genetic cholesteryl ester transfer protein deficiency caused by two prevalent mutations as a major determinant of increased levels of high density lipoprotein cholesterol

Genetic determinants of HDL cholesterol (HDL-C) levels in the general population are poorly understood. We previously described plasma cholesteryl ester transfer protein (CETP) deficiency due to an intron 14 G(+1)-to-A mutation(Int14 A) in several families with very high HDL-C levels in Japan. Subjects with HDL-C > or = 100 mg/dl (n = 130) were screened by PCR single strand conformational polymorphism analysis of the CETP gene. Two other mutations were identified by DNA sequencing or primer-mediated restriction map modification of PCR products: a novel intron 14 splice donor site mutation caused by a T insertion at position +3 from the exon14/intron14 boundary (Int14 T) and a missense mutation (Asp442 to Gly) within exon 15 (D442G). The Int14 T mutation was only found in one family. However, the D442G and Int14 A mutations were highly prevalent in subjects with HDL-C > or = 60 mg/dl, with combined allele frequencies of 9%, 12%, 21% and 43% for HDL-C 60-79, 80-99, 100-119, and > or = 120 mg/dl, respectively. Furthermore, prevalences of the D442G and Int14 A mutations were extremely high in a general sample of Japanese men (n = 236), with heterozygote frequencies of 7% and 2%, respectively. These two mutations accounted for about 10% of the total variance of HDL-C in this population. The phenotype in a genetic compound heterozygote (Int14 T and Int14 A) was similar to that of Int14 A homozygotes (no detectable CETP and markedly increased HDL-C), indicating that the Int14 T produces a null allele. In four D442G homozygotes, mean HDL-C levels (86 +/- 26 mg/dl) were lower than in Int14 A homozygotes (158 +/- 35 mg/dl), reflecting residual CETP activity in plasma. In 47 D442G heterozygotes, mean HDL-C levels were 91 +/- 23 mg/dl, similar to the level in D442G homozygotes, and significantly greater than mean HDL-C levels in Int14 A heterozygotes (69 +/- 15 mg/dl). Thus, the D442G mutation acts differently to the null mutations with weaker effects on HDL in the homozygous state and stronger effects in the heterozygotes, suggesting dominant expression of a partially defective allele. CETP deficiency, reflecting two prevalent mutations (D442G and Int14 A), is the first example of a genetic deficiency state which is sufficiently common to explain a significant fraction of the variation in HDL-C in the general population.

The activities of 5 beta-reductase and 11 beta-hydroxysteroid dehydrogenase in essential hypertension

The activities of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) and 5 beta-reductase were analyzed in 39 normotensive controls and 128 patients with essential hypertension. The activity of 11 beta-HSD was obtained by dividing the 24-hour urinary tetrahydrocortisone by the sum of tetrahydrocortisol (THF) and allotetrahydrocortisol (aTHF), whereas the activity of 5 beta-reductase was obtained by dividing the 24-hour urinary THF by aTHF. The activity of 5 beta-reductase was significantly lower in essential hypertensives compared with normotensive controls (P < 0.05). However, the activity of 11 beta-HSD did not differ between normotensive controls and essential hypertensives. A positive correlation between the activities of 11 beta-HSD and 5 beta-reductase was observed in essential hypertensives (r = 0.60, P < 0.01). Neither 11 beta-HSD nor 5 beta-reductase activity correlated with indices of renal mineralocorticoid receptor activation, which were assessed by determination of plasma potassium and urinary excretion of sodium as well as potassium. Taken together, these results suggest that disturbances of one of the inactivation pathways of cortisol may contribute to the pathogenesis of hypertension.

Ischemic heart disease in patients with diabetes mellitus in Japan

The risk of death by ischemic heart disease (IHD) in patients with diabetes mellitus is higher than in non-diabetics, and the average life span of the diabetics is shorter than in non-diabetics in Japan. There is no direct correlation between the occurrence of IHD and severity or glycemic control of diabetes. However, the mortality by IHD increases in diabetic patients with severe retinopathy and/or massive proteinuria. Regarding the management of IHD, diabetes is not considered a contraindication to thrombolytic therapy. The indication and results of percutaneous transluminal coronary angioplasty and coronary bypass surgery are the same as in non-diabetics.

Vascular aldosterone. Biosynthesis and a link to angiotensin II-induced hypertrophy of vascular smooth muscle cells

Mineralocorticoids have been suggested to act on blood vessels, leading to increased vasoreactivity and peripheral resistance. However, the site of their production has so far been believed to be only the adrenal cortex. Here, we show direct evidence that vascular cells per se are aldosteronogenic, possessing their own system that responds to the steroid. Using polymerase chain reaction after reverse transcription, the CYP11B2 mRNA encoding the key enzyme for the biosynthesis of aldosterone was detected in both endothelial cells and smooth muscle cells cultivated from human pulmonary artery. The aldosterone receptor (type 1 mineralocorticoid receptor) gene was also found to be expressed in smooth muscle cells and, to a lesser extent, in endothelial cells. CYP11B2 gene expression in smooth muscle cells was stimulated by angiotensin II, the effector peptide of the renin-angiotensin system. Furthermore, the angiotensin II-induced increase in [3H]leucine incorporation in smooth muscle cells was significantly enhanced by aldosterone but inhibited by ZK 91587, a type 1 mineralocorticoid receptor antagonist. This may indicate that vascular aldosterone participates in the angiotensin II-induced hypertrophy of vascular smooth muscle cells. The present study therefore provides the starting point for a novel understanding of the molecular basis of vascular remodeling and hypertension.

Marked improvement of diabetic diarrhea with the somatostatin analogue octreotide

Somatostatin and its long-acting analogue octreotide have been used in various diarrheal disorders, including neoplastic and nonneoplastic diseases of the gastrointestinal tract. In two insulin-dependent diabetic patients with autonomic neuropathy and chronic steatorrheic diarrhea refractory to conventional medications, subcutaneous administration of octreotide markedly improved the volume and frequency of stools in both patients. This change was accompanied by a clear improvement in their rapid gastrointestinal tract transit times. The treatment also greatly improved their orthostatic hypotension. No adverse effects of octreotide were observed after treatment for 7 months in one patient and 2 months in the other.

Angiotropic B-cell lymphoma with hemophagocytic syndrome

A unique autopsy case of angiotropic lymphoma, which is a rare lymphoma characterized by the lymphoma cells confined in blood vessels and with a minimal involvement of lymph nodes, is presented. The clinical diagnosis was a malignant histiocytosis (histiocytic medullary reticulosis), since clinical manifestations were muscle weakness of the extremities, pancytopenia, fever and hepatosplenonephromegaly, and biopsy exhibited infiltration by histiocytic cells showing hemophagocytosis in the liver sinusoids and the bone marrow, the latter with myelofibrosis. Postmortem examination revealed lymphoma cell proliferation within small blood vessels of the kidneys, perineural tissue of extremities and lungs. Lymph nodes were not involved. In the liver, spleen and bone marrow, prominent infiltration of benign histiocytic cells with active hemophagocytosis was evident but there was no lymphoma cell infiltration. No viral infection, including Epstein-Barr (EBV), was demonstrable either serologically or immunohistochemically. Autopsy diagnosis was angiotropic lymphoma of B-cell origin (immunophenotypically CD 45+, CD 20-related+, CD 45R+, CD 45 RO-, CD 43-, CD 57-, CD 30-, CD 68-) accompanied by hemophagocytic syndrome clinicopathologically simulating malignant histiocytosis.

Effect of aging on urinary excretion of 18-hydroxycortisol

The secretion of aldosterone declines with age. We reported that sodium depletion increased urinary excretion of 18-hydroxycortisol (18-OH-F). To elucidate the effect of aging on urinary excretion of 18-OH-F, we measured urinary 18-OH-F in 30 normotensive subjects aged 20-70 yr. There were significant negative correlations between age and urinary excretion of 18-OH-F or of aldosterone (r = -0.49, r = -0.58, P < 0.05, respectively) but not of urinary free cortisol. These results suggest that angiotensin may contribute to chronic regulation of 18-OH-F.

Angiotensin II up-regulates the expression of type A endothelin receptor in human vascular smooth muscle cells

Using vascular smooth muscle cells, the effect of angiotensin II on endothelin receptor regulation was examined. Vascular smooth muscle cells cultivated from human pulmonary artery exhibited high affinity receptors for endothelin-1. When the cells were exposed to angiotensin II, the number of receptors was found to be increased without any change in their affinity. The ligand binding was effectively displaced by BQ123, a selective antagonist for type A endothelin receptor, but not by S6c, a selective ligand for type B receptor, in both control and angiotensin II-treated cells. The level of mRNA coding for the type A receptor was elevated in the latter. These results indicate that angiotensin II up-regulates type A endothelin receptors in human vascular smooth muscle cells through an increase in their corresponding mRNA, suggesting a link between the renin-angiotensin and the endothelin systems.

Induction of the renal pelvic and ureteral carcinomas by N-butyl-N-(4-hydroxybutyl)nitrosamine in SD/cShi rats with spontaneous hydronephrosis

We attempted to establish an animal model for renal pelvic and ureteral carcinomas. In Experiment 1, Sprague-Dawley (SD)/cShi and SD/gShi strains of male and female rats and Fischer-344 (F-344)/DuCrj and LEW/Crj strains of male rats, 6 wk old, were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) for 12 wk and then treated without chemical for 10 wk. Only the SD/cShi strain, which has spontaneous hydronephrosis and hydroureter, showed high incidences of carcinomas in the renal pelvises and ureters, whereas the other strains did not. In Experiment 2, SD/cShi and Crj:CD strains of male and female rats, 6 wk old, were exposed to 0.05% BBN for 20 wk. Both sexes of SD/cShi rats had high incidences of bilateral carcinomas in renal pelvises and/or ureters associated with urinary bladder carcinomas, whereas both sexes of Crj:CD rats had urinary bladder tumors only. These results indicate that the SD/cShi strain may be a suitable animal for the induction of renal pelvic and ureteral carcinomas that appear to depend on urine stagnation secondary to hydronephrosis and hydroureter.

Biosynthetic pathway of 19-noraldosterone in isolated rat glomerulosa cells

The biosynthetic pathway of 19-noraldosterone (19-noraldo) in isolated rat glomerulosa cells (GC) and fasciculata-reticular cells (FC) was studied by analyzing [14C]pregnenolone metabolism using HPLC and quantification by specific RIA. In GCs, 18,19-dihydroxycorticosterone was detected after 15 min incubation with [14C]pregnenolone, 18-hydroxy-19-norcorticosterone was detected after 30 min and 19-noraldo was detected after 45 min before the appearance of an aldosterone peak. These three mineralocorticoids were not detected in FCs. The results demonstrate that 19-noraldo is synthesized in GCs and then undergoes further metabolism.

Gene expression of 11 beta-hydroxysteroid dehydrogenase in the mesenteric arteries of genetically hypertensive rats

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) modulates the access of corticosteroids to their receptors and plays an important role in controlling blood pressure. We determined 11 beta-HSD activity and mRNA levels in the mesenteric arteries of genetically hypertensive rats, the Dahl salt-sensitive hypertensive rat, and compared them with Dahl salt-resistant and Sprague-Dawley rats. 11 beta-HSD activity was expressed as the percent conversion of [3H]corticosterone to [3H]11-dehydrocorticosterone. 11 beta-HSD activity was significantly decreased in the mesenteric arteries of 8-week-old Dahl salt-sensitive hypertensive rats (11.4 +/- 1.4%) compared with Dahl salt-resistant rats (17.4 +/- 1.4%) or Sprague-Dawley rats (18.0 +/- 1.5%) of the same age (P < .05). There were no significant differences in 11 beta-HSD activity between 4-week-old Dahl salt-sensitive hypertensive and Dahl salt-resistant rats of the same age (15.3 +/- 1.3% and 15.1 +/- 1.9%, respectively). The concentration of 11 beta-HSD mRNA in the mesenteric arteries of 8-week-old Dahl salt-sensitive hypertensive rats was significantly lower than in Dahl salt-resistant or Sprague-Dawley rats of the same age (P < .05). There were no significant differences in the concentration of 11 beta-HSD mRNA in the mesenteric arteries of 4-week-old Dahl salt-sensitive hypertensive rats, Dahl salt-resistant rats, and Sprague-Dawley rats. These results indicate that 11 beta-HSD in the vascular wall may play a role in the pathogenesis of hypertension in this rat model.

Type IV collagen in hypertrophic cardiomyopathy

Basement membrane of myocytes from patients with hypertrophic cardiomyopathy who died suddenly, seemed to be discontinuous by immunohistochemical methods. With the use of the sandwich immunoassay technique, we determined the frequency of type IV collagen and its influence on functional abnormality in 31 patients with hypertrophic cardiomyopathy and controls. Hypertrophic cardiomyopathy exhibited significantly increased serum type IV collagen compared with controls. A significant correlation was observed between serum type IV collagen and fractional shortening (r = -0.42 p < 0.05), and end-diastolic volume (r = 0.40 p < 0.05), DT (r = -0.50 p < 0.05). These data suggest that serum type IV collagen enhances clusters of cell-surface type IV collagen, including an alteration of the cytoskeleton, which may account for functional abnormalities in hypertrophic cardiomyopathy. Considering the fact that microscopic examination is unable to resolve the structure of the myocardial basement membrane, measurement of serum type IV collagen is thought to be useful in the diagnosis of myocardial basement membrane injury and the progression of hypertrophic cardiomyopathy.

Detection of anomalous origin of the left coronary artery by transesophageal echocardiography and magnetic resonance imaging

Anomalous origin of the left coronary artery can lead to angina pectoris, acute myocardial infarction or even sudden death, especially during exercise. We present a patient in whom the anomalous origin of the left coronary artery from the posterior aortic (non-coronary) sinus produced ischemic chest pain. The anomaly was identified by transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) as well as by coronary angiography. TEE and MRI are useful for detecting anomalies of the coronary artery both clearly and noninvasively and for evaluating the mechanism of ischemia.

Expression of PC2 and PC1/PC3 in human pheochromocytomas

Expressions of two Kex2-related proteases, Pc2 and PC1/PC3, and of one of their possible substrates, proenkephalin, were examined in normal (n = 7) and various pathological (n = 48) human adrenal tissues. Northern blot analysis detected the expression of these genes in pheochromocytomas only. In the 20 pheochromocytomas studied with this technique, PC2, PC1/PC3 and proenkephalin were expressed in 85%, 50% and 90%, respectively. The presence of PC2 and PC1/PC3 was further confirmed using the sensitive RT/PCR techniques. Other evidence of human tumoral adrenal medullary PC2 expression was provided by in situ hybridization and immunohistochemistry. In addition, proenkephalin was expressed only in the pheochromocytomas expressing PC2 and/or PC1/PC3. These results demonstrate that functional Kex2-related endoproteases are expressed in human pheochromocytomas and may be involved in the processing of proenkephalin.

Increased feline cerebral blood flow induced by dehydroevodiamine hydrochloride from Evodia rutaecarpa

Dehydroevodiamine hydrochloride (0.1-0.3 mg/kg iv), which was isolated from the leaves of Evodia rutaecarpa, increased the cerebral blood flow recorded from the surface of the supra-sylvian gyrus in anesthetized cats. This action reached a maximum 1-4 min after injection and continued for 10 min. However, the compound had negligible effects on other cardiorespiratory functions at the doses examined. These results suggest that the compound selectively increases cerebral blood flow.