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Y Kikkawa

Publications and source records attributed to Y Kikkawa.

At least 109 records · Page 6Linked to original sources
PubMed1982

Increased saturated phospholipid in cultured cells grown with linoleic acid.

We found that fetal bovine serum supplementation of culture medium provided limited quantities of linoleic acid, an essential fatty acid, to cells grown in culture (2.8 +/- 0.3% of total fatty acids in 12 lots). Supplementation of the medium with additional linoleic acid resulted in altered phospholipid acyl composition in cells of two established lines, A549, a putative model of the pulmonary Type II epithelial cell, and SIRC, a line derived from rabbit corneal epithelium. In particular, linoleic acid supplementation induced a relative increase in disaturated choline phosphoglycerides of 33 and 36%, respectively, in cells of the two lines. This observation may be relevant to design of media for primary culture of Type II cells, in which disaturated phospholipid synthesis used as an index of differentiated function (surfactant production). Linoleate supplementation did not alter growth or size (protein content) of cells of either line and caused a slight increase in accumulation of neutral lipid, in the form of cytoplasmic droplets, in A549 cells. Supplementation of cell cultures with equivalent concentrations of the nonessential fatty acids palmitic and oleic acid did not significantly alter the growth, morphologic appearance, or lipid composition of the cells. However, it was demonstrated in cells of one line that palmitic acid supplementation temporarily stimulated synthesis of disaturated choline phosphoglyceride from radiolabeled choline.

Animals↗
PubMed1982

Morphometry of right ventricular hypertrophy induced by strenuous exercise in rat.

Effects on the myocardium, particularly those structural properties of the capillary network relevant to tissue oxygenation, were studied morphometrically in rats subjected to a severe running program. Physical conditioning produced a 31% increase in right ventricular weight and only a 12% increase in the weight of the left ventricle. Quantitative analysis of right ventricular myocardium demonstrated relative decreases in capillary luminal volume density (-27%) and capillary luminal surface density (-20%) and an increase in the average maximum distance from the capillary wall to the mitochondria of myocytes (14%). In contrast, the contractile mass expanded in proportion to the growth of the ventricle through augmentation of the cross-sectional area (17%) and length (19%) of the average myocyte. Evaluation of the subcellular constituents of myocytes showed no change in the mitochondria-to-myofibril volume ratio. In conclusion, the capillary bed controlling oxygen availability, diffusion, and transport suggests that excessive physical activity may be detrimental to the myocardium.

Animals↗
PubMed1980

The type II epithelial cells of the lung. VI. Incorporation of 3H-choline and 3H-palmitate into lipids of cultured type II cells.

We measured incorporation of 3H-labeled lipid precursors into surfactant-associated and nonsurfactant associated phospholipids in 2- to 7-day primary cultures of rabbit type II alveolar epithelial cells, in order to assess the degree to which cells retain metabolic features related to surfactant production in vitro. Unsaturated phosphatidyl choline label increased progressively in type II cell monolayers grown in the continuous presence of 3H-choline, but label in saturated phosphatidyl choline, the surfactant-associated fraction, remained constant after 2 days in culture. Although type II cell cultures could be stimulated to increase saturated phosphatidyl choline production by brief exposure to 8.5 x 10(-5) M palmitic acid, this response proved to be transient. Type II cells synthesized the other major surfactant-associated lipid, phosphatidyl glycerol, from 3H-palmitic acid in vitro, in proportions decreasing from 6.3 per cent of total lipid synthesis in fresh cell isolates to 1.8 per cent in 2-day cultures and 1.4 per cent in 4-day cultures. Aging of the cell cultures was also associated with a proportionate decrease in synthesis of neutral lipids and increases in synthesis of phosphatidyl choline, sphingomyelin, and phosphatidyl inositol, from palmitic acid. We conclude that: (1) isolated type II alveolar cells continue synthesis of surfactant-related lipid species, a major index of differentiated function, for at least 4 days after introduction into cell culture; (2) production of non-surfactant related lipids occupies a progressively larger portion of type II cell lipid synthetic activity during this period, probably reflecting increased synthesis of cell membranes.

Animals↗
PubMed1978

The freeze-fracture study of alveolar type II cells and alveolar content in fetal rabbit lung.

Freeze-fracture replication technique was utilized to study the morphology of type II alveolar epithelial cells and alveolar contents in the late gestation of rabbit fetuses. It was shown that the lamellar inclusion bodies of type II cells were enveloped by the usual type of unit membrane with membrane-associated particles of 15 nm diameter. The interior of the inclusion bodies was composed of multiple stacks and/or whorls of membranes which were devoid of membrane-associated particles. Small vesicles within the inclusion were found more frequently with this technique than in chemically fixed thin-sectioned preparations. The intra-alveolar contents were comprised of two components; sperical bodies, which were identical to the internal contents of the lamellar bodies of type II cells, and tubular elements. These tubules most often appeared rectangular on cross-fractured faces. Triangular hexagonal fracture faces were also noted. The tubules were seen to rest on the surfaces of the spherical components. Our observations suggest that the tubular element of alveolar contents is formed through the interaction between the discharged lamellar body content and the alveolar fluid, and further suggest that at least the major constituent of type II cell lamellar bodies is lipid not bound to protein. Three new observations were made in this study; the absence of membrane-associated particles on the interior of the lamellae of the inclusions, the cross-fractured profiles of tubular elements of the alveolar contents, and the occasional multicompartmental nature of type II cell inclusions.

Animals↗
PubMed1978

The type II epithelial cells of the lung. III. Lecithin synthesis: a comparison with pulmonary macrophages.

Synthesis of lecithins in isolated type II alveolar cells was compared with that in alveolar macrophages as a means of exploring the biochemical mechanisms underlying surfactant production in the lung. Counted cell populations were suspended in a simple glucose-salt solution and 14C-labeled precursors were added singly, in physiologic concentrations, to assess the potential importance of each as a substrate for lecithin synthesis. Molar incorporation of glucose, glycerol, choline, lysolecithin, acetate, palmitate, oleate, and linoleate was determined in lecithins fractionated according to degree of saturation after 1 hour of incubation. Palmitate ws the most actively utilized substrate in type II &cells. Type II cells incorporated 6 nmoles of palmitate per 10(7) cells, of which 77% was in disaturated lecithins, and 66% at the C2 position (compared to 0.8 nmoles, 47% disaturated, in macrophages). Acetate was also incorporated mainly into disaturated lecithins in type II cells; macrophages did not utilize acetate, and no precursor specifically supported disaturated lecithin synthesis in macrophages. Type II cells and macrophages synthesized similar quantities of total lecithins and disaturated lecithins from glucose and choline. Only the type II cells, however, were capable of increasing disaturated lecithin synthesis from 14C-choline when unlabeled palmitate was added to the medium. Type II cells synthesized significantly more disaturated lecithins from lysolecithin than did macrophages (451 versus 60 pmoles per 10(7) cells). Macrophages utilized glycerol in lecithin synthesis, but type II cells did not. Our data demonstrate directly for the first time that type II cells are the site of disaturated lecithin synthesis and that acyl turnover mechanisms are important in production of disaturated lecithins by the type II cell.

Acetates↗
PubMed1977

An animal model of cigarette smoking in beagle dogs: correlative evaluation of effects on pulmonary function, defense, and morphology.

Using beagle dogs, we have developed an animal model for the evaluation of the effect of chronic cigarette smoking on pulmonary defense and function and on lung structure. The smoking apparatus developed allows the dog actively to inhale properly diluted (1:4) smoke directly from the cigarette through a mouthpipe. In this model, 6-month and 1-year periods of mild to moderate smoking caused impairment of tracheal mucociliary transport and bacteriosuppressive activity of alveolar macrophages, with little change in pulmonary function. Morphologically, subtle, but significant, lesions were noted in the central airways and bronchiolar walls, consisting of tracheal epithelial basal cell hyperplasia, proliferation of goblet cells in central airways, and peribronchiolar infiltration by inflammatory cells. Morphometry of bronchiolar size distribution, volume proportion of parenchymal structure, and alveolar surface area, however, failed to show significant differences between the groups.

Animals↗
PubMed1977

The type II epithelial cells of the lung. IV. Adaption and behavior of isolated type II cells in culture.

Type II lung epithelial cells were isolated from rabbit lungs using the method of Kikkawa and Yoneda (Kikkawa Y, Yoneda K: Lab Invest 30: 76, 1974). Successful primary cultures were obtained only after utilizing high density cell plating (greater than 3 X 10(5) viable cells per sq. cm.) and allowing an attachment time of 48 hours. Attachment efficiency of the isolated cell preparations was highest when medium was supplemented with 10% fetal calf serum. These conditions enabled us to obtain consistently successful primary type II lung cell cultures. Cultures were monitored for a period of 2 weeks after initiation. Light, phase, and electron microscopy examination demonstrated that these primary cultures were indeed type II cells. The principal morphologic feature was the presence of dense lamellar granules in these cells. These primary cultures retained the characteristic type II features for 3 to 5 days in vitro, after which cultures exhibited a progressive deterioration and loss of their phenotypic properties. This behavioral pattern of type II cells in culture may represent both accelerated proliferation and accelerated transformation of these cells into type I epithelial cells.

Animals↗
PubMed1976

Morphologic and biochemical study of pulmonary changes induced by bleomycin in mice.

Pulmonary changes induced by bleomycin were investigated in mice by using light and electron microscopy and by phospholipid analysis of the alveolar washings. The damage began in the endothelium of capillaries and was accompanied by interstitial edema and an appearance of enlarged macrophages along with hypertrophy of type II epithelial cells. This condition was followed by degeneration of type I cells. The denuded epithelium appeared to be repaired by two different mechanisms. In areas away from the bronchioles, division of existing type II cells and subsequent transformation into type I cells appeared to be the pattern of epithelial repair. In areas near the bronchiole, downgrowth of bronchiolar undifferentiated cells and subsequent maturation of these cells to type II and type I cells appeared to be prominent. Biochemically, total phospholipids and disaturated lecithin in the alveolar wash increased along with the increase of the alveolar lining layer and the hypertrophy of type II cells. This was considered to be consistent with the view that the hyperactive type II cells secreted more surfactant in the early phase of the experiment.

Animals↗
PubMed1976

Helical structure of human native collagen.

A "fibroleiomyoma" of the lung obtained from a 40-year-old man as a surgical specimen was studied with both the light and the electron microscope. The unusual collagen in this tumor displayed a filamentous helical structure. The filaments measured 50 Angstroms across. Most of the fibrils did not show periodicity. Some, however, showed periodicity of about 700 A. Those with periodicity were smaller in diameter than the fibrils without periodicity. These observations suggest a helical structure of native collagen and may also represent weak cross-linking of tropocollagen in this tumor. This is the first report of collagen showing a helical filamentous structure from human material.

Adult↗
PubMed1975

The type II epithelial cells of the lung. II. Chemical composition and phospholipid synthesis.

A method to isolate 93 per cent viable (trypan blue), 95 plus or minus 2 per cent pure type II alveolar epithelial cells (Kikkawa, Y., and Yoneda, K. Lab. Invest. 30: 76, 1974) was slightly modified and was used to isolate type II cells of similar purity and viability from New Zealand White male rabbits. The modification as described in this report now permits the regular harvest of 20 to 30 times 10-6 cells from a rabbit weighing 2 to 4 kg. Lipid composition of type II cell pools thus collected was compared with that of macrophages collected by alveolar washing. Per milligram of protein, type II cells contained 19 mug. of lipid phosphorus, compared with 11 mug. for macrophages. Per 1 times 10-8 cells, type II cells contained 110 mug. of lipid phosphorus compared with 155 mug. for macrophages; Phosphatidylcholine comprised 48 per cent of total phospholipid in type II cells and 34 per cent in macrophages. Forty-nine per cent of the phosphatidylcholine in type II cells was disaturated, compared with 29 per cent in macrophages. These data indicate that, per cell, type II cells contain almost twice as much disaturated phosphatidycholine as do alveolar macrophages. Radiolabeled precursor studies suggest that isolated type II cells synthesize disaturated lecithin predominantly through the cytidine diphosphocholine pathway. -14C-choline incorporation into disaturated lecithin was 3 times as active in type II cells as in macrophages. No evidence was found for a significant contribution to synthesis of disaturated lecithin by the transmethylation pathway in isolated type II cell preparations. These results offer the most direct evidence to date of the significant role of the type II alveolar epithelial cell in the synthesis of disaturated lecithin, a major constituent of pulmonary surfactant.

Animals↗
PubMed1975

Interstitial nephritis with concomitant uveitis. Report of two cases.

In two female pediatric cases of uveitis with proteinuria and glycosuria, kidney biopsy demonstrated the presence of interstitial nephritis. Peripheral leukocytes responded positively in vitro in the leukocyte migration inhibition test with renal tubular antigen, thus suggesting the possibility that the patients' lymphocytes infiltrating into the renal parenchyma might be sensitized against the renal tubular antigen. Urinary beta2-microglobulin was also demonstrable and its levels correlated fairly well with the clinical course of uveitis in both cases.

Adolescent↗