Evidence for an effect of sodium pumping on spontaneous contractility of rabbit detrusor muscle

The role of sodium pump in the inhibition of smooth muscle responsiveness to agonists during potassium restoration

“…The lack of change of resting tension of the spleen strips when exposed to potassium-free medium at least during the first 2-3 h differs from the beh-aviour of the rat portal vein (Axelsson, Wahlstrom, Johansson & Jonsson, 1967), guineapig taenia coli (Tomita & Yamamoto, 1971), rabbit detrusor muscle (Paton, 1971) and occasionally the rabbit coronary artery (Norton & Detar, 1972). The reason for this difference is not clear.…”

The role of sodium pump in the inhibition of smooth muscle responsiveness to agonists during potassium restoration

“…The lack of change of resting tension of the spleen strips when exposed to potassium-free medium at least during the first 2-3 h differs from the beh-aviour of the rat portal vein (Axelsson, Wahlstrom, Johansson & Jonsson, 1967), guineapig taenia coli (Tomita & Yamamoto, 1971), rabbit detrusor muscle (Paton, 1971) and occasionally the rabbit coronary artery (Norton & Detar, 1972). The reason for this difference is not clear.…”

Effect of Potassium on the Mechanical Activity of Taenia Coli, Uterus and Portal Vein of the Guineapig

“…The initial inhibitory response should not be confused with the inhibitory effect of the re-introduction of a K+-containing solution, such as normal Krebs' solution, after incubation in a K+-free medium, as has been reported for several smooth muscles (rat uterus [Taylor, Paton and Daniel, 1970]; guinea-pig taenia coli [Casteels, Droogmans and Hendrickx, 1971]; rabbit detrusor muscle [Paton, 1971]; guinea-pig portal vein [Kuriyama, Ohshima and Sakamoto, 1971]; cat carotid artery [Bose and Innes, 1972]; rabbit uterus [Johns and Paton, 1974]). Casteels, Droogmans and Hendrickx, [1973] and Hendrickx and Casteels [1974] have suggested that this response occurs through the action of an electrogenic sodium-potassium pump which is stimulated by an increase in external potassium [see also Anderson, 1976].…”

Influence of sodium pumping on smooth muscle contraction

“…The sodium pump in smooth muscle of rabbit urinary bladder and rat uterus has been shown to be electrogenic under special conditions which cause sodium enrichment of these muscles (Taylor, Paton & Daniel, 1970;Paton, 1971). These preparations were incubated first in cold potassium-free medium, with a consequent increase in tissue sodium.…”

“…If this is true, it appears that an elevated intracellular sodium or decreased potassium activity is responsible for making the sodium pump electrogenic. The method we have used to show an inhibitory role of the sodium pump, with stimulation of the muscle in the absence of potassium, is quicker and perhaps less drastic than the method of cold storage in a potassium-free medium used by Taylor et al (1970) and Paton (1971).…”

“…Discussion-In two smooth muscle preparations with an electrogenic sodium pump, viz. rat uterus and rabbit urinary bladder, removal of external potassium resulted in depolarization (Taylor et al, 1970) and contraction (Paton, 1971). Absence of contraction in the spleen after similar treatment suggests that appreciable depolarization probably did not occur.…”

The role of sodium pump in the inhibition of smooth muscle responsiveness to agonists during potassium restoration

“…The lack of change of resting tension of the spleen strips when exposed to potassium-free medium at least during the first 2-3 h differs from the beh-aviour of the rat portal vein (Axelsson, Wahlstrom, Johansson & Jonsson, 1967), guineapig taenia coli (Tomita & Yamamoto, 1971), rabbit detrusor muscle (Paton, 1971) and occasionally the rabbit coronary artery (Norton & Detar, 1972). The reason for this difference is not clear.…”

Effect of Potassium on the Mechanical Activity of Taenia Coli, Uterus and Portal Vein of the Guineapig

“…The initial inhibitory response should not be confused with the inhibitory effect of the re-introduction of a K+-containing solution, such as normal Krebs' solution, after incubation in a K+-free medium, as has been reported for several smooth muscles (rat uterus [Taylor, Paton and Daniel, 1970]; guinea-pig taenia coli [Casteels, Droogmans and Hendrickx, 1971]; rabbit detrusor muscle [Paton, 1971]; guinea-pig portal vein [Kuriyama, Ohshima and Sakamoto, 1971]; cat carotid artery [Bose and Innes, 1972]; rabbit uterus [Johns and Paton, 1974]). Casteels, Droogmans and Hendrickx, [1973] and Hendrickx and Casteels [1974] have suggested that this response occurs through the action of an electrogenic sodium-potassium pump which is stimulated by an increase in external potassium [see also Anderson, 1976].…”

Influence of sodium pumping on smooth muscle contraction

“…The sodium pump in smooth muscle of rabbit urinary bladder and rat uterus has been shown to be electrogenic under special conditions which cause sodium enrichment of these muscles (Taylor, Paton & Daniel, 1970;Paton, 1971). These preparations were incubated first in cold potassium-free medium, with a consequent increase in tissue sodium.…”

“…If this is true, it appears that an elevated intracellular sodium or decreased potassium activity is responsible for making the sodium pump electrogenic. The method we have used to show an inhibitory role of the sodium pump, with stimulation of the muscle in the absence of potassium, is quicker and perhaps less drastic than the method of cold storage in a potassium-free medium used by Taylor et al (1970) and Paton (1971).…”

“…Discussion-In two smooth muscle preparations with an electrogenic sodium pump, viz. rat uterus and rabbit urinary bladder, removal of external potassium resulted in depolarization (Taylor et al, 1970) and contraction (Paton, 1971). Absence of contraction in the spleen after similar treatment suggests that appreciable depolarization probably did not occur.…”

The role of sodium pump in the inhibition of smooth muscle responsiveness to agonists during potassium restoration

“…The lack of change of resting tension of the spleen strips when exposed to potassium-free medium at least during the first 2-3 h differs from the beh-aviour of the rat portal vein (Axelsson, Wahlstrom, Johansson & Jonsson, 1967), guineapig taenia coli (Tomita & Yamamoto, 1971), rabbit detrusor muscle (Paton, 1971) and occasionally the rabbit coronary artery (Norton & Detar, 1972). The reason for this difference is not clear.…”

Effect of Potassium on the Mechanical Activity of Taenia Coli, Uterus and Portal Vein of the Guineapig

“…The initial inhibitory response should not be confused with the inhibitory effect of the re-introduction of a K+-containing solution, such as normal Krebs' solution, after incubation in a K+-free medium, as has been reported for several smooth muscles (rat uterus [Taylor, Paton and Daniel, 1970]; guinea-pig taenia coli [Casteels, Droogmans and Hendrickx, 1971]; rabbit detrusor muscle [Paton, 1971]; guinea-pig portal vein [Kuriyama, Ohshima and Sakamoto, 1971]; cat carotid artery [Bose and Innes, 1972]; rabbit uterus [Johns and Paton, 1974]). Casteels, Droogmans and Hendrickx, [1973] and Hendrickx and Casteels [1974] have suggested that this response occurs through the action of an electrogenic sodium-potassium pump which is stimulated by an increase in external potassium [see also Anderson, 1976].…”

Influence of sodium pumping on smooth muscle contraction

“…The sodium pump in smooth muscle of rabbit urinary bladder and rat uterus has been shown to be electrogenic under special conditions which cause sodium enrichment of these muscles (Taylor, Paton & Daniel, 1970;Paton, 1971). These preparations were incubated first in cold potassium-free medium, with a consequent increase in tissue sodium.…”

“…If this is true, it appears that an elevated intracellular sodium or decreased potassium activity is responsible for making the sodium pump electrogenic. The method we have used to show an inhibitory role of the sodium pump, with stimulation of the muscle in the absence of potassium, is quicker and perhaps less drastic than the method of cold storage in a potassium-free medium used by Taylor et al (1970) and Paton (1971).…”

“…Discussion-In two smooth muscle preparations with an electrogenic sodium pump, viz. rat uterus and rabbit urinary bladder, removal of external potassium resulted in depolarization (Taylor et al, 1970) and contraction (Paton, 1971). Absence of contraction in the spleen after similar treatment suggests that appreciable depolarization probably did not occur.…”