The ultrastructure of the gastric glands and its relation to induced secretory activity of cod, Gadus morhua (Day)

Abstract

Light and electron microscopic studies have been performed on different parts of cod stomach. The studies have been concentrated on the gastric glands of the gastric mucosa. The glands consist of only one cell type. This cell contains an apically located, comprehensive tubular system as well as zymogen granules and therefore probably secretes both acid and zymogen. The high degree of development of certain organelles and their mutual localization shows a structural organization which appears suitable for an effective secretion. What appears to be intermediate organelle forms are common. When acid secretion is increased by continuous intramuscular infusion of histamine or of carbachol the most marked structural changes are increases in the size of the gland lumen and in the cell membrane facing the lumen. Histamine in particular causes the appearance of numerous long and slender cell processes in an enlarged gland lumen. When the acid secretion, increased by histamine, had reached a plateau, metiamide was infused. This histamine H2-receptor antagonist caused a decrease in acid secretion as well as in the size of the gland cell surface to values characteristic of untreated cod.

Comparative morphology and cytology of the alimentary tract in lizardfishes (Teleostei, Aulopiformes, Synodontidae)

“…Observation of the tract contents revealed that the major digestion of the engulfed prey and major absorption occurs in the stomach and the pyloric part of the intestine. Mattisson and Holstein (1980) and Osman and Caceti (1991), in contrast, described only one cell type in the digestive glands of the cod, Gadus morhua and of the cichlid, Oreochromis niloticus, respectively. As in other fishes, the digestive glands of the lizardfish are tubular, densely packed below the mucosa and opening as pits into the gut lumen (Elbal et al 1988;Gallagher et al 2001).…”

“…Numerous studies of the alimentary tract in fishes have focused on a single species, such as Esox lucius by Bucke (1971); Gadus morhua by Mattisson and Holstein (1980), and Oreochromis niloticus (Tilapia) by Osman and Caceti (1991) and Morrison and Wright (1999), to mention only a few. Numerous studies of the alimentary tract in fishes have focused on a single species, such as Esox lucius by Bucke (1971); Gadus morhua by Mattisson and Holstein (1980), and Oreochromis niloticus (Tilapia) by Osman and Caceti (1991) and Morrison and Wright (1999), to mention only a few.…”

“…The alimentary tract in fishes bears a strong similarity to that of higher vertebrates, being composed of an internal mucosal epithelium surrounded by sub-mucosal connective tissue and muscularis, which are enveloped by the circular and longitudinal muscles that form the walls of the tract, and finally the enveloping serosa, a part of the peritoneal tissue. Numerous studies of the alimentary tract in fishes have focused on a single species, such as Esox lucius by Bucke (1971); Gadus morhua by Mattisson and Holstein (1980), and Oreochromis niloticus (Tilapia) by Osman and Caceti (1991) and Morrison and Wright (1999), to mention only a few. The most recent review of the gastrointestinal tract in fishes (Wilson and Castro 2010), includes an extensive bibliography of such studies.…”

Effect of 5-HT on basal and stimulated secretions of acid and pepsin and on gastric volume outflow in thein vivo gastrically and intestinally perfused cod,Gadus morhua

“…The three agents carbachol, histamine, and 5-HT show that the cod stomach is capable of a differentiated output of acid and pepsin. This is worth pointing out, because in fish and other submammalian vertebrates, acid and pepsin are considered the products of the same, oxynticopeptic cell [39,44,45].…”

Cellular expression of the pepsinogen and gastric proton pump genes in the stomach of winter flounder as determined by in situ hybridization

“…In fish, as well as in amphibians, reptiles and birds, the pepsinogens and hydrochloric acid are secreted by a single type of gastric cell known as the oxynticopeptic cell (Helander, 1981). This cell type in fish possesses certain structural characteristics common to both the peptic and oxyntic cells of mammals (Rebolledo & Vial, 1979;Mattisson & Holstein, 1980;Stroband & Kroon, 1981;Murray et al, 1994). The oxynticopeptic cell has been shown to secrete pepsinogens in some fish species (Reifel et al, 1985;Yasugi et al, 1988;Inui et al, 1995;Huang et al, 1998) and hydrochloric acid in others (Smolka et al, 1994), but none of these studies has demonstrated both functions in the same oxynticopeptic cell of a single species.…”