Ionic requirements of transepithelial potential difference and net water flux in the perfused midgut of the american lobster, Homarus americanus

Sodium and glucose transport across the in vitro perfused midgut of the blue crab, Callinectes sapidus Rathbun

“…Transmural potential difference of the same polarity and magnitude is also exhibited by the midgut of ~. rosenbergii (Ahearn, 1980), and the American lobster, Homarus americanus (Mykles, 1981).…”

“…Johnson (1980) also ascribed peri trophic membrane formation to be a function of the midgut epithelium of Q. sapidus. In Homarus arnericanus, net fluid absorption through the midgut is sodium-dependent (Mykles, 1981). In Macrobrachium rosenbergii, this uptake is dependent on the presence of both sodium and chloride .…”

“…Using the in vitro perfusion technique, the ion and water transport properties of the midgut of M. rosenbergii and H. americanus have been investigated in considerable depth Ahearn, 1978;Ahearn, Koosawad & Hadley, 1978;Ahearn, 1980;Wyban, Ahearn & Maginniss, 1980;Mykles, 1981). The findings are summarized as follows.…”

“…In accordance with the standing gradient model of isotonic water transport (Diamond, 1964;Diamond & Bossert, 1967), they proposed that in the freshwater shrimp midgut, water diffuses passively down a local osmotic gradient that presumably is built up in the intercellular spaces by a coupled Na-Cl transport in the mucosal border. A similar model to account for Na+-dependent net water transport across the midgut of H. americanus was proposed by Mykles (1981). He suggested that the extensive network of smooth endoplastic reticulum in the basal portion of the epithelial cells may be the site of the standing osmotic gradient responsible for transmural water absorption.…”

Sodium and glucose transport across the in vitro perfused midgut of the blue crab, Callinectes sapidus Rathbun

“…Transmural potential difference of the same polarity and magnitude is also exhibited by the midgut of ~. rosenbergii (Ahearn, 1980), and the American lobster, Homarus americanus (Mykles, 1981).…”

“…Johnson (1980) also ascribed peri trophic membrane formation to be a function of the midgut epithelium of Q. sapidus. In Homarus arnericanus, net fluid absorption through the midgut is sodium-dependent (Mykles, 1981). In Macrobrachium rosenbergii, this uptake is dependent on the presence of both sodium and chloride .…”

“…Using the in vitro perfusion technique, the ion and water transport properties of the midgut of M. rosenbergii and H. americanus have been investigated in considerable depth Ahearn, 1978;Ahearn, Koosawad & Hadley, 1978;Ahearn, 1980;Wyban, Ahearn & Maginniss, 1980;Mykles, 1981). The findings are summarized as follows.…”

“…In accordance with the standing gradient model of isotonic water transport (Diamond, 1964;Diamond & Bossert, 1967), they proposed that in the freshwater shrimp midgut, water diffuses passively down a local osmotic gradient that presumably is built up in the intercellular spaces by a coupled Na-Cl transport in the mucosal border. A similar model to account for Na+-dependent net water transport across the midgut of H. americanus was proposed by Mykles (1981). He suggested that the extensive network of smooth endoplastic reticulum in the basal portion of the epithelial cells may be the site of the standing osmotic gradient responsible for transmural water absorption.…”

Ecdysteroid Treatment Delays Ecdysis in the Lobster, Homarus americanus

“…Intact lobsters (5.5 g) at various substages of stage D 3 received a single injection (0.2, 1 .0, or 5.0 ^g/g wet weight) of 20-hydroxyecdysone (20-HE; Rohto Pharmaceutical; purity checked by high-performance liquid chromatography before use). Control animals received vehicle only (lobster saline; Mykles, 1981).…”

Sodium and glucose transport across the in vitro perfused midgut of the blue crab, Callinectes sapidus Rathbun

“…Transmural potential difference of the same polarity and magnitude is also exhibited by the midgut of ~. rosenbergii (Ahearn, 1980), and the American lobster, Homarus americanus (Mykles, 1981).…”

“…Johnson (1980) also ascribed peri trophic membrane formation to be a function of the midgut epithelium of Q. sapidus. In Homarus arnericanus, net fluid absorption through the midgut is sodium-dependent (Mykles, 1981). In Macrobrachium rosenbergii, this uptake is dependent on the presence of both sodium and chloride .…”

“…Using the in vitro perfusion technique, the ion and water transport properties of the midgut of M. rosenbergii and H. americanus have been investigated in considerable depth Ahearn, 1978;Ahearn, Koosawad & Hadley, 1978;Ahearn, 1980;Wyban, Ahearn & Maginniss, 1980;Mykles, 1981). The findings are summarized as follows.…”

“…In accordance with the standing gradient model of isotonic water transport (Diamond, 1964;Diamond & Bossert, 1967), they proposed that in the freshwater shrimp midgut, water diffuses passively down a local osmotic gradient that presumably is built up in the intercellular spaces by a coupled Na-Cl transport in the mucosal border. A similar model to account for Na+-dependent net water transport across the midgut of H. americanus was proposed by Mykles (1981). He suggested that the extensive network of smooth endoplastic reticulum in the basal portion of the epithelial cells may be the site of the standing osmotic gradient responsible for transmural water absorption.…”

Ecdysteroid Treatment Delays Ecdysis in the Lobster, Homarus americanus

“…Intact lobsters (5.5 g) at various substages of stage D 3 received a single injection (0.2, 1 .0, or 5.0 ^g/g wet weight) of 20-hydroxyecdysone (20-HE; Rohto Pharmaceutical; purity checked by high-performance liquid chromatography before use). Control animals received vehicle only (lobster saline; Mykles, 1981).…”

Sodium and glucose transport across the in vitro perfused midgut of the blue crab, Callinectes sapidus Rathbun

“…Transmural potential difference of the same polarity and magnitude is also exhibited by the midgut of ~. rosenbergii (Ahearn, 1980), and the American lobster, Homarus americanus (Mykles, 1981).…”

“…Johnson (1980) also ascribed peri trophic membrane formation to be a function of the midgut epithelium of Q. sapidus. In Homarus arnericanus, net fluid absorption through the midgut is sodium-dependent (Mykles, 1981). In Macrobrachium rosenbergii, this uptake is dependent on the presence of both sodium and chloride .…”

“…Using the in vitro perfusion technique, the ion and water transport properties of the midgut of M. rosenbergii and H. americanus have been investigated in considerable depth Ahearn, 1978;Ahearn, Koosawad & Hadley, 1978;Ahearn, 1980;Wyban, Ahearn & Maginniss, 1980;Mykles, 1981). The findings are summarized as follows.…”

“…In accordance with the standing gradient model of isotonic water transport (Diamond, 1964;Diamond & Bossert, 1967), they proposed that in the freshwater shrimp midgut, water diffuses passively down a local osmotic gradient that presumably is built up in the intercellular spaces by a coupled Na-Cl transport in the mucosal border. A similar model to account for Na+-dependent net water transport across the midgut of H. americanus was proposed by Mykles (1981). He suggested that the extensive network of smooth endoplastic reticulum in the basal portion of the epithelial cells may be the site of the standing osmotic gradient responsible for transmural water absorption.…”

Ecdysteroid Treatment Delays Ecdysis in the Lobster, Homarus americanus

“…Intact lobsters (5.5 g) at various substages of stage D 3 received a single injection (0.2, 1 .0, or 5.0 ^g/g wet weight) of 20-hydroxyecdysone (20-HE; Rohto Pharmaceutical; purity checked by high-performance liquid chromatography before use). Control animals received vehicle only (lobster saline; Mykles, 1981).…”