摘要:

The electron immunocytochemical co-localization of prochymosin and pepsinogen in chief cells mucous neck cells and transitional mucous neck/chief cells of calf fundic glands was studied using specific antisera for prochymosin and pepsinogen with a protein A-gold method. Prochymosin and pepsinogen immunoreactivities were detected in the same secretory granules of the chief, mucous neck and transitional cells, simultaneously using small and large colloidal gold particles. In chief cells, both immunoreactivities were distributed uniformly over the same zymogen granules showing a round, large, homogeneous and electron-dense appearance. In mucous neck cells, both immunoreactivities were found exclusively on the same electron-dense core located eccentrically in the mucous granule showing light or moderate electron density. In transitional mucous neck/chief cells, electron-dense cores became larger in size and some granules were occupied by the electron-dense core without a halo between the core and the limiting membrane. Both immunoreactivities were found uniformly over the electron-dense core. The granules having no halo in the transitional cells could not be distinguished from the typical zymogen granules in the chief cells.

ISSN:1422-6405    

DOI:10.1159/000146581

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Freeze-fracture electron microscopy has been used to study tight junctions of epithelial cells in the rat fallopian tube. At oestrus junctions were found to consist of strands parallel to the surface whereas at day 6 of pregnancy, junctions were deeper and extensively interconnected. We consider the involvement of ovarian hormones and the cross-tissue significance of our findings.

ISSN:1422-6405    

DOI:10.1159/000146582

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Ultrastructurally, two different bipolar cell types can be distinguished in the retina of the chick embryo: one pale or electron-lucent and the other dark or electron-dense. The different electron density was seen over the whole cell, from its enclave in the outer limiting membrane to its termination in the inner plexiform layer.These observations prompted us to study the content and cytoplasmic variations of both cell types. The pale bipolar cell has a higher vacuole, vesicle and endoplasmic reticulum content and a lower number of microtubules and glycogen than the dark bipolar cell. The presence of these two cell types is probably due to a characteristic physiologic state, and the difference between the pale and dark bipolar cells can be attributed to the diverse number of gap unions which they establish with A II amacrine cells.

ISSN:1422-6405    

DOI:10.1159/000146583

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The anatomical pathways from the parvocellular reticular formation and medulla oblongata to the mesencephalic trigeminal nucleus (Mes V) were investigated in the rat by means of the anterograde tracer Phaseolus vulgaris leukoagglutinin. P. vulgaris was injected into the rostral ventromedial medulla, rostral and caudal ventrolateral medulla, the parvocellular reticular formation and surrounding regions. Rostral medullary regions and the parvocellular reticular formation projected to Mes V although the bilaterality, extent and density of the projections originating in these reticular structures showed clear variations. In experiments in which dorsolateral reticular areas were involved, we found the projections to the bilateral trigeminal nuclei to be most prominent. More caudal areas, including the spinal trigeminal nucleus caudalis, showed no projections to MesV.The present experiments show, for the first time, the existence of ipsilateral and crossed projections from the reticular formation to the MesV.These pathways are possibly involved in direct modulation of trigeminal reflexes.

ISSN:1422-6405    

DOI:10.1159/000146584

出版商:S. Karger AG    

年代:1988

数据来源: Karger