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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 703 records · Page 39Linked to original sources
PubMed1981

The adrenergic nerve supply to bovine ovarian follicles.

To obtain more exact knowledge of the adrenergic innervation around ovarian follicles at various stages, a combination of fluorescence and light microscopic observations of the same specimen was applied to the bovine ovary in the breeding season. We found no fluorescent nerve fibers in the membrana granulosa at any stages of follicular development. The sparse nerve fibers found in the theca interna of Graafian follicles were apparently those accompanying blood vessels, and such were considered not to play a significant role in the vasomotor control of follicular blood flow. The fluorescent fibers in the theca externa increased in density and intensity in the course of follicular development. This increase appears to coincide with the increasing contractility of the follicular wall around the time of ovulation.

Animals↗
PubMed1981

Modification of poly-L-lysine by treatment with 1,1-ethylene-bis(1-nitrosourea) in vitro.

N6-(Carbamoyl)-L-lysine (CA-Lys), N6-(2-imidazolidinone-N-carbonyl)-L-lysine (INC-Lys), and N6-(2-hydroxyethylcarbamoyl)-L-lysine (HEC-Lys) were synthesized. The radioactive products obtained from enzymatic hydrolysates of polylysine that had been reacted with 1,1'ethylene-bis(1-nitrosourea) (EBNU) [carbonyl-14C] and EBNU [ethylene-14C] coincided with the authentic samples of CA-Lys, INC-Lys, and HEC-Lys on thin-layer chromatography. The main product was CA-Lys and the amounts of other products, such as INC-Lys and HEC-Lys, were extremely small. CA-Lys was also isolated and identified from among the reaction products of EBNU and N1-tert-butyloxycarbonyl-L-lysine. These results demonstrate that EBNU carbamoylates polylysine at the N6-amino group of lysyl residues via various kinds of carbamoylating moieties derived from EBNU.

Chemical Phenomena↗
PubMed1981

[Scanning electron microscopic observations of microcorrosion casts for rabbit ovarian vasculature before ovulatory stimulus (author's transl)].

Ovarian vasculature of juvenile and adult rabbits was studied using a method of resin injection-corrosion casts. Arteries and arterioles in the ovarian stroma and capillary networks surrounding the follicles were observed on a three dimensional scale by scanning electron microscopy with the following findings: 1) The strongly coiled arteries are observed in adult rabbit ovaries. The first order arterioles arise from the spiral artery, and the second order arterioles stemming from these first order arterioles enter into each follicle. 2) Vasculature of follicles starts as glove-finger-like ramified capillary networks. As follicles grow, follicular vessels increase remarkably and form multilayered complex vascular networks surrounding the follicles. 3) The observations of circular impressions around the arterioles near the follicle and in the follicular wall suggest the existence of sphincteric control mechanism of blood flow into the follicle. 4) There are several pathways of venous drainage from a wall of large follicle and arterio-venous shunts are observed in the wall of such follicles. These structures may exert an important effect upon the follicular hemodynamics in the process of follicle rupture.

Animals↗
PubMed1981

[Histological studies of multiple subperitoneal nodules produced by prolonged administration of estrogen (author's transl)].

It has been reported that multiple peritoneal fibroids were produced in guinea pigs treated with large doses of estrogens, and the nodules regressed when the steroid stimulant was discontinued. Recently, these experimental nodules were considered to be simulating the disseminated pattern of Leiomyomatosis Peritonealis Disseminata (LPD). Although these experimental nodules were considered to be composed of fibroblasts by light-microscopic studies, LPD was verified to be composed of smooth muscle by electronmicroscopic studies. Therefore, it is indispensable to study these experimental nodules by electronmicroscopy, when we discuss about the similarities between experimental nodules and LPD. Guinea pigs were treated with various doses of estradiol benzoate (E) [40, 80, 100, 200 microgram/day, thrice a week, intramuscular injection]. After treatment for three months, every dose of E produced the lesions simulating the disseminated pattern of LPD: multiple nodules in various sizes, scattered on the surface of the uterine horn, peritoneum, spleen and pancreas, and in the omentum and mesocolon. Ultrastructurally, the nodules were composed of the cells resembling fibroblast. We conjectured that estrogen differentiates and proliferates the cells of the features of fibroblast-like cells from subcoelomic mesenchyme, resulting in the production of multiple superitoneal nodules simulating the disseminated pattern of LPD.

Animals↗
PubMed1981

[Ultrastructural observation of the ovulatory changes in the capillary of the human follicular apex (author's transl)].

To clarify its possible participation and mode of action in follicle rupture at human ovulation, the capillary in the apex of the ovarian follicle was investigated electronmicroscopically with 16 human ovaries. In the follicle at the mid-proliferative phase with 6 mm diameter, capillary lumen was narrow and empty. Capillary vessels observed in the theca interna of the preovulatory follicle were dilated and filled with blood cells. Their endothelial cells had indented nuclei and elongated thin cytoplasm with unusually irregular membranous protrusions. In cytoplasm there were numerous vesicles, some of which had fine granule-like contents of low electron density to be released into extracapillary space. These results indicate increased capillary permeability due to active transport around the time of ovulation. Polymorphonuclear leucocytes, rich in specific granules containing collagenase activity, were often observed in the capillary lumen as well as extracapillary space only close to the time of ovulation. This observation implies possible roles of leucocytes in collagen degradation. The present ultrastructural results suggest that the vast capillary network in the follicle wall plays an important role in the mechanism of follicle rupture through its increased permeability and collagenolytic activities of leucocytes.

Adult↗
PubMed1980

Cell cycle kinetics in human lymphocyte cultures.

Short-term cultures of phytohaemagglutinin (PHA)-stimulated human lymphocytes are widely used to detect chromosome-damaging agents, possible human exposure to mutagenic carcinogens and the immune response of blood. Because the results are affected by the number of cell divisions before sampling, an accurate knowledge of lymphocyte proliferation in culture is essential for these studies. Unfortunately, the information available on the lymphocyte proliferative characteristics is quite conflicting. For instance, although after stimulation of blood lymphocytes with PHA the cultures soon contain cells that have divided different numbers of times: this heterogeneity has been explained variously as a difference in cell-cycle times or in the times when the cells start blastogenesis by responding to PHA. Prolonged treatment with high concentrations of 3H-thymidine (TdR) have often been used to investigate lymphocyte proliferation. Incorporated 3H-TdR can, however, affect cell kinetics. The differential staining of sister chromatids in cells dividing for different numbers of times in the presence of bromodeoxyuridine (BUdR) can be used to study cell kinetics. In experiments combining sister chromatid differential staining and autoradiography, we show here that 3H-TdR labelling at more than 0.1 microCi ml-1 slows lymphocyte cycling, and that the heterogeneity of different generations of cells is caused by a difference in the times when they start their first DNA synthesis in response to PHA.

Autoradiography↗
PubMed1980

The role of the de novo synthetic pathway in forming molecular species of phospholipids in resting lymphocytes from human tonsils.

Phosphatidylcholine of resting human tonsil lymphocytes contained dipalmitoyl (18 mol%), 1-oleoyl,2-palmitoyl (11 mol%) and dioleoyl (5 mol%) species. 1-Oleoyl and 1-linoleoyl species were also detected in other more highly unsaturated phosphatidylcholine species. The features of phospholipid synthesis in lymphocytes were investigated by incubating cells with radiolabeled precursors. The de novo synthesis of phospholipids occurring in lymphocytes was estimated to be physiologically important, in particular for supplying dipalmitoylglycerophosphocholine and highly unsaturated phosphatidylethanolamine. It was also suggested that diacylglycerol(s) not originating from glycerophosphate is (are) involved in the synthesis of tetraenoic phospholipids. From radioactive palmitic and oleic acids were actively synthesized dipalmitoyl, dioleoyl and 1-oleoyl,2-palmitoyl species of diacylglycerol. The mode of diacylglycerol synthesis was reflected upon phosphatidylcholine formation. The formed polyunsaturated phosphatidylethanolamine was also found to contain 1-oleoyl or 2-palmitoyl species. Radioactive linoleic and arachidonic acids were incorporated predominantly into the C-1 position of diacylglycerol, whereas the majority of the formed phospholipids was of 2-linoleoyl or 2-arachidonoyl species. Labeled stearic acid was exclusively esterified to the C-1 position of the glycerolipids. However, the labeling pattern of molecular species by stearate was considerably deviated from that observed with labeled palmitate. These results indicate that the de novo synthetic pathway operating lymphocytes is primarily responsible for forming 1-unsaturated type of phospholipids. The synthesis of 1-saturated,2-unsaturated species appeared to be due to remodeling of once-formed phospholipids.

Chemical Phenomena↗