年森 清隆

Specific granules in porcine hearts were observed in atrial cardiocytes, Purkinje fibers, and transitional cells of the ventricle. These granule-containing cells were immunohistochemically stained by applying the avidin-biotin-peroxidase complex method using an antiserum against α-human atrial natriuretic polypeptide (ANP). Immunoelectron microscopy of sections stained using the immunogold method indicated that these specific granules are storage sites of ANP. Furthermore, an impulse-conducting system consisting of immunoreactive cells was clearly distinguishable from nonimmunoreactive ventricular cardiocytes. We conclude that specific-granule-containing cells, i.e., ANP-producing cells, are located in both the atrial walls and the ventricular impulse-conducting system. The presence of ANP may be correlated with impulse conduction. © 1987 Springer-Verlag.

The distribution of intramembranous particles (IMPs) and membrane filipin‐sterol complexes (FSC) was examined ultrastructurally in mouse spermatozoa from the male reproductive tract and ejaculates. IMPs were qualitatively analyzed on freeze‐fracture replicas of glutaraldehyde‐fixed tissue, while membrane FSC were quantitatively analyzed on replicas of filipin‐treated cells. The distribution pattern of IMPs of mouse spermatozoa was fundamentally similar to that of other mammalian spermatozoa. (1) In the head, the plasma membrane had a heterogeneous population density, e.g., few IMPs on the acrosomal region, particularly few on the marginal segment, and somewhat regularly arranged IMPs on the postacrosomal region. The acrosomal membrane had many IMPs in hexagonal arrays. The nuclear membrane had many IMPs on the P‐face, few IMPs on the variegated E‐face, and an intense population density on the P‐face of the basal plate. (2) In the neck, the plasma membrane had many IMPs with square arrangements of small IMPs in some areas on the P‐face the redundant nuclear membrane had a few IMPs on both P‐ and E‐faces. (3) In the tail, the plasma membrane had diagonal rows of IMPs in some areas amongst larger IMPs on the middle piece, while it had „zippers” composed of IMPs running parallel to the axis on the principal piece. The distribution of sperm membrane FSC may be summarized as follows: (1) In the head, the acrosomal plasma membrane, which was heavily labeled with filipin, had much more FSC in the equatorial segment than in the marginal segment throughout the study. The postacrosomal plasma membrane generally had no FSC, but some sperm in ejaculates were slightly positive to filipin. The acrosomal membranes (both outer and inner) had no FSC. The nuclear membrane in the main part of the head had less FSC in vas deferens and ejaculated sperm than in the epididymal sperm. The nuclear membrane on the basal plate had no FSC. (2) In the neck, the plasma membrane had little FSC. The redundant nuclear envelope had scattered FSC with a higher incidence in the epididymal sperm than in those from the vas deferens and ejaculates. The membrane scroll, which was elongated from the extreme caudal end of the redundant nuclear envelope, had abundant FSC in the vas deferens and ejaculated sperem. (3) The tail plasma membrane (both middle and principal piece), which was weakly labeled with filipin, had less FSC in sperm from the vas deferens and ejaculates than in those from the epididymis. The limiting membrane covering the mitochondria had no FSC. Copyright © 1985 Wiley‐Liss, Inc.

Ultrastructural characteristics including intercellular junctions of several kinds of constituent tissue cells were studied in 1 day postpartum rat uteri, using the freeze-fracture technique. Endometrial epithelial cells had tight junctions composed of 6–10 strands and desmosomes immediately below the lumen, and large gap junctions in the basal regions on the lateral cell membrane. The endothelial cells of the endometrial venules were characterized by tight junctional grooves without intramembranous particles (IMPs) on the E-face. Stromal cells (fibroblast-like cells) displayed linear elevations or depressions and gap junctions on the cleaved planes of the cell membranes. Smooth muscle cells (SMCs) showed many pinocytotic pits and IMPs (P-face 1582±227(n=11)/μm2E-face 487±60(n=5)/μm2). They were characterized by cytoplasmic bulbous protrusions on which IMPs were irregularly distributed. The SMCs sometimes phagocytosed collagen bundles through large circular depressions. Perimetrial mesothelial cells displayed tight junctions composed of 2–5 loosely organized elements and small gap junctions which were sometimes related to tight junctional strands. Even in such drastic tissue changes as occurs in the postpartum uterus, interconnections between the constituent tissue cells are thought to be relatively intense. © 1983 Medical Council on Alcoholism.

The zonulae occludentes between oviductal epithelial cells were quantitatively analyzed at diestrous and estrous stages in the mouse, using the freeze‐fracture technique. Zonulae occuldentes were predominantly anastomosing at the diestrous stage, while they were predominantly parallel at the estrous stage. The lowest mean value of junctional strands comprising the zonulae occludentes was 5.3 ± 1.6. Parallel‐type zonulae occludentes had more strands than the anastomosing type. Secretory cells usually had more strands than ciliated cells. The shallowest mean depth occupied by junctional domain was 0.51 ± 0.20 μm. The depth was usually somewhat greater in anastomosing‐type zonulae occludentes than in the parallel type. It was also slightly greater in ciliated cells than in secretory cells. The depth was likely to be greater at diestrous stage than at the estrous stage. However, neither the number of strands nor the depth was significantly different between diestrous and estrous stages in homologous types of zonulae occludentes. On the basis of these results, the zonulae occludentes in oviductal epithelium are considered to be morphologically of a tight type at any time period throughout the estrous cycle. The results of lanthanum tracer experiments suggest that the zonulae occludentes in the oviductal epithelium do not always function as a barrier to the exogenous tracer. These morphological phenomena are discussed in relation to mouse fertilization in vivo. Copyright © 1983 Wiley‐Liss, Inc.

Mouse fertilizing spermatozoa were examined by stereo-200kV electron microscopy at an early stage of penetration into the egg in vivo. The novel finding was of lamellar structures in and/or near the fertilizing sperm head in the ooplasm. The structures were usually located in the ooplasm between the fertilizing spermatozoon and the egg surface. Further, such membraneous structures were directly associated with the equatorial region of the fertilizing sperm head. It is inferred that the lamellar structures originated from the membrane system of fertilizing spermatozoon, especially from the nuclear membrane.

Amyloid fibrils were isolated from the kidneys of two Japanese patients with type I FAP and fractionated on Sephadex G-100 gel column. The elution pattern showed three peaks. Molecular weight of the third peak protein was about 14,000, which was absent in the chromatogram obtained from the tissue of a nonamyloidotic patient. Antisera raised against whole denatured amyloid fibril components reacted with this protein, giving rise to a precipitin arc on immunoelectrophoretic analysis in the area almost corresponding to prealbumin but slightly cathodal to it. The amino acid composition of this protein was different from those of AA protein, AL protein, or normal human PreA subunit. The major subunit GAM III of amyloid fibril protein (AFj) appears immunologically related to PreA. © 1981.