The ultrastructure of the gastric mucosa in normal and hypophysectomized rats

Abstract

The objectives of this study were to observe with the electron microscope ( a ) the epithelial cell types found in the neck and isthmus of the gastric fundic gland of the rat, and ( b ) the effects of hypuphysectomy on the gland. The following cell types were distinguished in the neck of the fundic gland of the rat: nondifferentiated cell, immature surface cell, mucous neck cell, and neck parietal cell. In the normal gland, these cell types resembled each other in the possession of a ground cytoplasm and nucleoplasm of low density, a poorly developed endoplasmic reticulum, few mitochondria and numerous free ribosomes. The most important structural difference between mucous neck and immature surface cells was the contrasting density of the secretory granules; both cell types differed from the nondifferentiated cell primarily in the presence of their characteristic secretory granules. The neck parietal cell appeared to be a developmental form between the immature surface cell and the mature parietal cell. No changes were observed in these cells to result from hypophysectomy.Hypophysectomy caused marked involutional changes in the chief cell which involved mainly the organelles most directly concerned with protein synthesis, i.e., the ergastoplasm and Golgi apparatus. These effects were correlated with the loss of basophilia and secretory granules and with the reduction in cell size and capacity to secrete pepsinogen which were described previously. In contrast, the parietal cell, which is concerned with electrolyte transport, was affected much less.

Panoramic observation of the mouse gastric mucosa by superwide-field electron microscopy.

“…However, undifferentiated cells in the present as well as previous studies (CORPRON, 1966;KATA-OKA, 1970) are identified as such by merely ultrastructural criteria: the absence of specific secretory granules, among others. Truly undifferentiated or pluripotential stem cells are difficult to identify by their morphology, and the contribution of such cells to new cell formation in the physiological renewal may be small, since morphologically identified undifferentiated cells are extremely scarce (Fig.…”

Immunohistochemical studies on the development of prochymosin‐ and pepsinogen‐containing cells in bovine abomasal mucosa.

“…The results presented here indicate that the non-differentiated neck cell, which has been suggested to represent the origin of the different cells in the gastric gland (Corpron, 1966;Rubin et al 1968;Matsuyama & Suzuki, 1970), has the capacity of producing both prochymosin and pepsinogen during the differentiation phase. When the diet is changed, i.e.…”

“…The ratios of the enzymes in the present material are shown in Table 1. DISCUSSION The secretion of chymosin from the gastric mucosa is highly correlated with milk-feeding and age (Garnot et al 1977;Andren et al 1980Andren et al , 1981 Several workers (Corpron, 1966;Rubin, Ross, Sleisenger & Jeffries, 1968;Matsuyama & Suzuki, 1970) have suggested that the mucous neck cell is the precursor of the chief cell, and Kataoka (1970) observed groups ofimmature chiefcells in the upper part of the base in gastric glands of the mouse. If this is so, the following hypothesis might explain the lack ofprochymosin-containing chief cells in the lower base of older animals (see also Fig.…”

Separation of Gastric Mucosal Cells of Rat with Proteolytic Enzymes, Pronase and Trypsin, with Special Reference to the Collection, Morphology and Viability of the Generative Cells

“…The ultimate purpose of our works is to establish cell lines from gastric mucosal cells, so that the interest was naturally focused on the separation of cells with growth potential, i.e. so-called immature, undifferentiated, indifferent and generative cells of the mucosa, which are called G-cells in this paper (Hunt and Hunt 1962;Corpron 1966;Johnson and Young 1968). Methods to obtain cell suspensions from the neck zone of the gastric mucosa of rats with high ratios of G-cells are reported and evaluated.…”