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Biomedical subjects

K Kumamoto

Publications and source records attributed to K Kumamoto.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Peptidergic innervation in the sinus hair follicles of several mammalian species].

In this study, the detailed distribution of peptidergic nerve fibers in the sinus hair follicle was immunohistochemically investigated by the avidin biotin-complex method using antibodies against calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY) in the cat, dog, hamster, rat, mouse and guinea pig. The peptide-immunoreactive (IR) nerve fibers presented a fine varicose appearance. They entered the sinus hair follicle after penetrating the capsule (Cap) at various levels. Peptide-IR fibers in the sinus hair were classified into the 3 types described below based on their course of entry and terminal distribution. Type A: these fibers arrive at the orifice of the sinus hair follicle from superficial dermis and innervate the upper portion of the follicle. Most of them form a network around the vibrissal shaft (VS) in the outer and inner conical body (OCB and ICB, respectively), and some are distributed around the rete ridge collar (RRC) and the sebaceous gland (SG). Type B: these fibers enter the lower third of the sinus hair follicle after forming a nerve bundle together with myelinated fibers, or accompany an artery. After distribution in the trabeculae (Trab) of the cavernous sinus (CS), they form a dense plexus in the connective tissue follicle (CTF) at the level of the CS. Some ascend through the CTF and terminate at the level of the ring sinus (RS). Type C: these fibers enter the sinus hair follicle at its base. They innervate the hair papilla (HP) and the CTF of the hair bulb. CGRP and SP were detected in all types of nerve fibers in all species investigated. These peptidergic nerve fibers showed the same distribution pattern, but CGRP fibers were more numerous than SP fibers. They were distributed at high density in the OCB, ICB, CTF, ringwulst (Rw), the Trab of the CS and the HP. A moderate number of VIP- and NPY-IR fibers, mainly types B and C, were detected in these portions in the cat, dog and hamster, but few fibers were observed in other portions or in other species. Although the basic structures of the sinus hair follicle presented almost the same features as in the mammalian species, the connective tissue of the HP extended to the level of the RS in the cat, rat, hamster, and guinea pig. In these species, CGRP-, SP- and/or VIP-IR fibers extended to the top of the papillary connective tissue, and in the cat, were especially well developed.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Stress increases the secretory product of rat nasal mucosa goblet cells.

The effect of stress on the secretory activity of rat nasal mucosa goblet cells was examined by quantitative histochemistry. Mucosa was prepared from the nasal septum of male rats with or without electric shock applied to the tail. Mucosa was fixed with formaldehyde and stained with alcian blue. The epithelial layer was further dissected, and examined microscopically. The percentage of stained area was estimated with the aid of a microscope connected to a computerized video system. The stained area, which corresponded to the secretory granules of mucosal goblet cells, was greater in the electrically shocked group than the control group. This result raises the possibility that stress enhances the secretory activity of goblet cells in nasal mucosa.

Alcian Blue↗
PubMed1990

Distribution of branched-chain fatty acid in the skin surface lipid of laboratory animals.

1. The distribution of the branched-chain fatty acid (BCFA) was studied in skin surface lipids of laboratory animals (rat, mouse, hamster and rabbit) and the experimental animal for the study of the metabolic fate of BCFA was chosen. 2. The monoester fraction resistant to microbial degradation was the index of which fatty acids were identified and the compositions were analyzed by capillary gas chromatography and mass spectrometry (GC-MS). 3. The contents of monoester fractions in rat, mouse, hamster and rabbit were 78.9, 15.9, 30.4 and 45.6% of the total skin surface lipid, respectively. 4. BCFAs were exclusively identified to be either iso- or anteiso-series type by means of mass spectrometry. 5. The sum of iso- and anteiso-acid was the highest in hamster comprising 53% in male and 38% in female of the monoester acid. 6. Sex related differences of BCFA concentration were not so evident in the other three species. 7. BCFA contents in the monoester fractions were as follows: rat 32%, mouse 25% and rabbit 3%. 8. Concentrations of iso-series fatty acid were consistently higher than that of anteiso-series type in all animals studied. 9. Abundance of 2-hydroxy fatty acid in the rabbit monoester fraction was noted for the first time. 10. Suitability of these laboratory animals for the study of BCFA metabolism was discussed.

Animals↗
PubMed1989

Brain natriuretic peptide in the porcine spinal cord: an immunohistochemical investigation of its localization and the comparison with atrial natriuretic peptide, substance P, calcitonin gene-related peptide, and enkephalin.

Immunohistochemistry was used to localize brain natriuretic peptide in the porcine spinal cord and to compare it with that of atrial natriuretic peptide, substance P, calcitonin gene-related peptide and [Met]enkephalin. Brain natriuretic peptide-immunoreactive varicose fibers were observed in lamina I and the inner portion of lamina II of the dorsal horn. Semiquantitative analysis showed that the highest density of brain natriuretic peptide-immunoreactive varicosities was in the lumbosacral and coccygeal segments. The distributional pattern of brain natriuretic peptide-immunoreactive nerve fibers in the spinal cord was unique and quite distinct from that of the other neuropeptides studied. These neuroanatomical findings suggest that brain natriuretic peptide may play a role in the regulation of nociceptive processing in the spinal cord, either alone or with bioactive substances.

Animals↗
PubMed1989

Evaluation of programs for the diagnosis, treatment and follow-up of hypertension in work site population.

Hypertensives screened among a work-site male population were treated either with or without antihypertensive drugs according to WHO stage of hypertension, and followed up by medical teams at the work site. The outcome during 8 years of follow-up was compared between two hypertension cohorts; one (cohort 1) instituted in 1970 included 1,092 hypertensives from 11,860 employees, while the other (cohort 2) made in 1975 contained 1,190 from 10,789 persons. Age-adjusted mortality or morbidity rate from cardiovascular diseases (CVD) was lower in cohort 2 than in cohort 1. Multiple regression analysis was used to adjust inter-cohort differences in factors to influence the prognosis, showed that CVD occurred less frequently in cohort 2 than in cohort 1. The results suggest that this system of controlling blood pressure is useful in preventing CVD in a large population.

Cardiovascular Diseases↗
PubMed1988

Glucose tolerance in middle-aged Japanese males with uncomplicated hypertension.

Plasma glucose levels in 50 g oral glucose tolerance test (OGTT) were compared between uncomplicated hypertensives (n = 507, mean age = 48 +/- 0.3 years) and normotensives (n = 378, mean age = 46 +/- 0.3 years). The subjects were selected in a systematic way from 10,120 male employees in a work-site population in Japan. None of hypertensives took any antihypertensive drugs. Plasma glucose levels at each time point of OGTT were significantly higher in the hypertensives than in the normotensives when the differences in age, obesity, and other factors that might influence glucose metabolism were adjusted, using multiple linear regression analysis. Similarly, multiple regression analysis for subjects including both normotensives and hypertensives revealed a significant relationship between plasma glucose levels and blood pressure, which was independent of age and body mass index. These findings indicate a more direct association between hypertension and hyperglycemia, which is not mediated via aging or obesity.

Blood Glucose↗
PubMed1987

Rare case of the inferior mesenteric artery arising from the superior mesenteric artery.

The authors observed a variation of the inferior mesenteric artery, which arose from the superior mesenteric artery, in a 69-year-old Japanese male cadaver during dissection in 1984. In this case, no rudiment of the ordinary inferior mesenteric artery could be found on the abdominal aorta. There are few reports of this variation, and an extensive search of the available literature revealed only four cases, including two in Japan. Such a variation had been somewhat inadequately described as an "absence of the inferior mesenteric artery" in the previous reports, but we avoided this terminology, because all of the cases possessed an artery, which, though arising from the superior mesenteric artery instead of the abdominal aorta, had the same branches as a normal inferior mesenteric artery. Consistent with findings observed in the previous cases, the unusual inferior mesenteric artery arose as the first branch of the superior mesenteric artery, with the common trunk of both mesenteric arteries originating from the abdominal aorta at a level at which an ordinary superior mesenteric artery would arise. It is for this reason that we did not adopt another acceptable name, that is, "the common mesenteric artery," for this variation. The variation can be explained as the result of an unusual development of the embryonic artery system, which comprises a number of ventral splanchnic arteries interconnected by longitudinal anastomotic channels to supply the primitive digestive tube.

Aged↗
PubMed1984

Antiulcer actions in rats of new synthetic polyisoprenoids.

The effects of 3-N,N-dimethylaminopropyl farnesyl acetate (DMFA), N'-geranylpiperazinyl farnesyl acetamide (GPFA) and N'-methylpiperazinyl geranylgeranyl acetamide (MPGA) were studied on gastric secretion, gastric bleeding and gastric mucosubstances in rats. DMFA lowered gastric juice and gastric bleeding, and GPFA increased gastric mucosubstances and decreased gastric bleeding. MPGA showed remarkable effects for all of these tests. Consequently it might be said that MPGA is a useful agent against both aggressive and resistant factors on gastric functions.

Alcian Blue↗
PubMed1983

Activation of renin-angiotensin system in maintenance of high blood pressure in uncomplicated pheochromocytoma--a case report.

In a patient with an uncomplicated pheochromocytoma, we observed high basal value of plasma renin activity (PRA), 16.2 ng/ml/h, and a remarkable elevation in PRA from 18.2 to 90.4 ng/ml/h and concomitant blood pressure reduction following a single oral administration of 25 mg of captopril. The response was same as that observed in renovascular hypertensives, and disappeared during the period of alpha-, beta-blocker administration or after the surgery. Basal PRA also returned to low normal level. The renin-angiotensin (R-A) system probably had a role in the maintenance of high blood pressure. The mechanism of the activation of the R-A system was thought to be renal vasoconstriction due to excessive circulating catecholamines.

Adrenal Gland Neoplasms↗
PubMed1982

Renin response to furosemide differs with the routes of administration in health men.

Plasma renin activity (PRA) was serially determined 0, 15, 30, 60 and 120 min following administration of furosemide in a dose of 40 mg intravenously (i.v.) and 80 mg orally (p.o.) at a one week interval in 10 healthy men. Following i.v. furosemide administration, PRA increased rapidly and reached a plateau level of 6.1 +/- 1.0 ng/ml/h (222 +/- 44% of the control), at 15 min and remained at about the same level throughout the remaining period of the study. In contrast, PRA increased progressively to a maximum level of 5.5 +/- 0.7 ng/ml/h (285 +/- 53% of the control), 120 min after p.o. furosemide. In case of p.o. furosemide, the increase in PRA was dependent on the doses used per body weight, and was significantly correlated with the cumulative sodium excretion by itself, or the cumulative sodium excretion adjusted by either the leanness index or the body surface area. Such relationships were not apparent after i.v. furosemide. These findings suggest that the response of renin release to furosemide in healthy men differs with the routes of administration and renin release with p.o. furosemide may be largely due to a net sodium loss, while mechanism(s) other than sodium loss may be involved in the early hypersecretion of renin with i.v. administration of furosemide.

Administration, Oral↗
PubMed1982

Evaluation of plasma renin activity by blood pressure level (pressure-renin index) in patients with essential hypertension.

Under various conditions of sodium balance, 1-sarcosine-8-isoleucine angiotensin II was infused into 15 normotensive controls and 82 patients with benign essential hypertension. Changes in mean blood pressure induced by the analogue were correlated with the logarithm of plasma renin activity (r = -0.763, p less than 0.001 for the controls; r = -0.776, p less than 0.001 for the patients). Although the coefficients of determination were much the same, 0.95 confidence limits of the regression line did not overlap at renin levels over 7 ng/ml/h. At those levels, a decrease in the mean blood pressure induced by the analogue was greater in the hypertensive patients. A pressure-renin index was defined as a product of the logarithm of plasma renin activity and the mean blood pressure measured before the analogue infusion. The correlation between the analogue effect and the pressure-renin index was highly significant (r = -0.763, p less than 0.001 for the controls; r = -0.777, p less than 0.001 for the hypertensive patients). The regression line (0.95 confidence limit) for the hypertensives coincided with that for the normotensives. Thus, the blood pressure level should be taken into account when attempting to evaluate plasma renin activity.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1981

Prolylcarboxypeptidase (angiotensinase C) in human lung and cultured cells.

The activity of prolylcarboxypeptidase (PCP), or angiotensinase C, was measured in lung tissues, leukocytes, and cultured human cells using Cbz-Pro-[14C]Ala as a substrate. A lysosomal fraction of homogenized rat or human lung contained most of the PCP activity in that tissue. Polymorphonuclear neutrophils, macrophages, and lymphocytes isolated from human blood had PCP activity. Fibroblasts cultured from human tissues had the highest activity (0.56-1.15 mumol/h per 10(6) cells), more than endothelial cells cultured from human pulmonary arteries. PCP of cultured human fibroblasts was similar to the human renal enzyme because it was resistant to moderate heating and was not inhibited by p-chloromercuriphenyl sulfonic acid. These properties and the substrate specificity distinguish PCP from cathepsin A, which is also in fibroblasts. Antibody to human renal PCP reacted with fibroblast PCP in immunofluorescence, indicating common antigenic determinants. Hydrocortisone changed PCP activity in fibroblasts in parallel with changes in beta-glucuronidase activity and cell-protein concentration; the activity was depressed at low concentration of the hormone. PCP activity was also found in synovial fluid from arthritic joints and in fibroblasts from the synovium. That PCP is found in both inflammatory exudates and in cells that appear at sites of inflammation indicates that, in addition to inactivating angiotensins, this enzyme may have a role in inflammation.

Angiotensin II↗
PubMed1980

Influence of unilateral adrenalectomy on renin-angiotensin-aldosterone system in primary aldosteronism.

In a study of 14 patients (11 Japanese and 3 white North Americans) with aldosterone-producing tumor carried out within 2 to 4 weeks after unilateral adrenalectomy, both plasma renin activity (PRA) and plasma aldosterone concentration (PAC) increased almost normally with short-term sodium depletion and upright posture. Aldosterone excretion rate (AER) also increased significantly with sodium depletion, and was normally suppressed by sodium loading. Highly significant correlations were observed between PRA and PAC (r=0.89, p < 0.001) or AER (r=0.88, p < 0.001) ater operation, whereas there had been no such correlation before operation. Either physiological or laboratory findings were normalized or markedly improved in all cases although pathohistological diagnosis was made as adenomatous hyperplasia in 10 out of 11. These results indicate that within 4 weeks of operation PRA and the remaining adrenal gland can almost normally respond to stimuli such as sodium depletion and upright posture regardless of the amount of spironolactone given preoperatively.

Adrenal Gland Neoplasms↗
PubMed1979

Ultrastructural types of cell in adrenal cortical adenoma with primary aldosteronism.

By means of electron microscopy, three types of cell were identified in the adrenal cortical adenomas obtained by surgery from three patients with primary aldosteronism. They were zona glomerulosa-type cells, compact cells and clear cells. The former two types of cell were quite similar to those found in the zona glomerulosa and the zona reticularis respectively. The clear cell with large lipid vacuoles possessed mitochondria similar to those found in the outer zona fasciculata. The ultrastructure of the vacuoles was rather complex and their relationship to those in the zona fasciculata cell was not clear. Glycogen particles in the beta-form, which were present in the zona glomerulosa and reticularis cell but not in the zona fasciculata cell, were observed within the cytoplasm of this tumour cell. The clear cells of the tumours were therefore considered to possess features of both the zona glomerulosa and the zona fasciculata cell.

Adenoma↗
PubMed1979

Individual renin-aldosterone responses of clinically healthy young Japanese men to dietary sodium and posture.

Responses to the changes in dietary sodium and posture were investigated in 9 young clinically healthy Japanese males who customarily consumed a larger amount of salt than North Americans or Europeans of mixed white ethnic background. Plasma renin activity (PRA), plasma aldosterone concentration (PAC), and urinary aldosterone excretion rate (AER) differed at each end of 3- to 4-day spans on a "control", a high-salt and a low-salt diet and of furosemide administration. PRA and PAC, also determined during the upright position following the supine blood sampling, increased after only 1 hour of standing in each condition (p less than 0.05 or more). PRA and PAC were well correlated in all 4 conditions, regardless of the posture (r = 0.806, p less than 0.001). There were also highly significant correlations between the "supine" PRA or PAC and the preceding 24-hour AER (r = 0.869, p less than 0.001) for PRA; r = 0.855, p less than 0.001 for PAC). Correlation coefficients between PRA and PAC in 9 individual subjects ranged from 0.823 to 0.987. The estimates of constant and slope of the regression line between PRA and PAC varied from subject to subject. The renin-aldosterone axis in response to changes in dietary sodium and posture must be individually assessed.

17-Hydroxycorticosteroids↗