The effects of alkaline earths and other divalent cations on adrenal medullary secretion

Douglas, W. W.; Rubin, Ronald P.

doi:10.1113/jphysiol.1964.sp007514

Cited by 117 publications

(44 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sr 2+ and Ba 2+ can effectively substitute for Ca 2+ in driving synaptic transmission. 6,[25][26][27][28][29] Once vesicle fusion occurs with the pre-synaptic membrane, the continuation of the fusion process is mainly regulated by factors unrelated to its initiation. Since amperometric spikes represent the collapse of single vesicles, substituting the charge carrier would not be expected to lead to large changes in spikes kinetics.…”

Section: Discussionmentioning

confidence: 99%

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca²⁺-Channel Modify Fusion-Pore Kinetics

Marom¹,

Sebag²,

Atlas³

2007

Channels

View full text Add to dashboard Cite

Strontium (Sr 2+ ), Barium (Ba 2+ ) and Lanthanum (La 3+ ) can substitute for Ca 2+ in driving synaptic transmission during membrane depolarization. Ion recognition at the polyglutamate motif (EEEE), comprising the channel selectivity-filter, during voltage-driven transitions, controls the kinetics of the voltage-gated calcium channel (VGCC) and its interactions with the synaptic proteins. We tested the effect of different charge carriers on evoked-release, as a means of exploring the involvement of VGCC in the fusion pore configuration. Employing amperometry recordings in single bovine chromaffin cells we show that the size of the fusion pore, designated by the 'foot'-amplitude, was increased when Ba 2+ substituted for Ca 2+ and decreased, with La 3+ . The fusion pore stability, indicated by 'foot'-width, was decreased in La 3+ . Also, the mean open time of the fusion pore (t fp ) was significantly lower in Sr 2+ and La 3+ compared to Ba 2+ and Ca 2+ . These cations when occupying the selectivity filter reduced the spike frequency in the order of Ca 2+ > Sr 2+ > Ba 2+ > La 3+ , which is parallel to the reduction in total catecholamine release. The correlation between ion binding at the selectivity filter and fusion pore properties supports a model in which the Ca 2+ channel regulates secretion through a site at the selectivity filter, upstream to cation entry into the cell.

show abstract

Section: Discussionmentioning

confidence: 99%

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca²⁺-Channel Modify Fusion-Pore Kinetics

Marom¹,

Sebag²,

Atlas³

2007

Channels

View full text Add to dashboard Cite

show abstract

“…The replacement of calcium by strontium and barium has been described in a number of tissues, strontium being found less effective than calcium in chopped lung (Mongar, 1970) at the neuromuscular junction (Miledi, 1966) and in adrenal chromaffin in tissue (Douglas & Rubin, 1964). In contrast, the action of strontium in the mast cell is more effective than that of calcium if histamine release is used as an index.…”

Section: Discussionmentioning

confidence: 99%

“…J. C. FOREMAN AND J. L. MONGAR There have been several studies of the antagonism between calcium and magnesium at the neuromuscular junction (Jenkinson, 1957;Dodge & Rahamimoff, 1967;Bloich, Glagoleva, Liberman & Nenashev, 1968), and strontium is able to substitute for calcium in the activation of transmitter release at the neuromuscular junction (Miledi, 1966;Dodge, Miledi & Rahmamimoff, 1969). Douglas & Rubin (1964) have reported that strontium will substitute for calcium in the activation of catecholamine release from adrenal chromaffin tissue. Strontium will also replace calcium in the process leading to the secretion of neurohypophysial hormones (Buchs, Dreifuss, Grau & Nordmann, 1972).…”

Section: Introductionmentioning

confidence: 99%

The role of the alkaline earth ions in anaphylactic histamine secretion

Foreman¹,

Mongar²

1972

The Journal of Physiology

211

126

View full text Add to dashboard Cite

SUMMAY1. Anaphylactic histamine release from rat peritoneal mast cells is dependent on the presence of calcium ions. Graded increase of histamine release occurs as the calcium ion concentration is raised from 041 to 10 m-mole/l.2. Magnesium antagonizes the effect of calcium. The dissociation constant of the Mg-receptor complex was found to be 9-4 m-molefl.3. Strontium will replace calcium ions in the activation of anaphylactic histamine release. Graded increase of histamine release occurs when the strontium ion concentration is raised from 1.0 to 10-0 m-mole/l. 4. Magnesium also antagonizes the effect of strontium. The dissociation constant of the magnesium-receptor complex was found to be 11.0 m-mole/l.5. The log concentration-effect curve for strontium has a greater maximum and steeper slope than the curve for calcium.6. Measurements of the interaction of calcium and strontium ions are in agreement with the hypothesis that strontium possesses a higher efficacy but a lower affinity than calcium, for the 'calcium receptor' in mast cells.7. Barium will replace calcium in the activation of anaphylactic histamine release.

show abstract

“…The ability of Sr and Ba to substitute for Ca in secretion induced by Na-free medium Sr and Ba have been shown to mimic Ca in that each induced secretion when introduced during perfusion with Cadeficient medium and restored the responses to ACh and excess K otherwise absent in this solution (Douglas & Rubin, 1964). As shown in Figure 6, Sr or Ba could substitute for Ca to maintain secretion by Na-free medium in a concentration which, in the presence of Na, never induced secretion.…”

Section: Perfusionmentioning

confidence: 99%

Exocytotic Secretion of Catecholamines From the Cat Adrenal Medulla by Sodium Deprivation: Involvement of Calcium Influx Mechanism

Nishimura

Sorimachi

Yamagami

1981

British J Pharmacology

View full text Add to dashboard Cite

Cat adrenal glands were perfused with Ca‐deficient medium and secretion of catecholamines (CA) was induced by perfusion with Na‐free medium in which NaCl was replaced by an osmotically equivalent amount of sucrose. Release of CA and dopamine‐β‐hydroxylase (DBH), but not that of phenylethanolamine‐N‐methyltransferase, was concomitantly found in the effluents when the adrenals were stimulated, indicating that secretion was due to exocytosis. Secretion of CA induced by Na‐free (sucrose) medium was dependent on the concentration of Ca and was saturated at 0.5 mm of Ca. Sr or Ba substituted for Ca in maintaining secretion by Na‐free (sucrose) medium. The addition of Na, Li or alkali metal ions to Na‐free (sucrose) medium containing Ca reduced the response to a variable extent but this inhibition was reversed by raising the concentration of Ca in the Na‐free medium. All of the Na substitutes used induced secretion only when this medium contained Ca. However, different Na substitutes released different amounts of CA; sucrose was most effective, K, Tris and choline were moderately and Li least effective. Secretion of CA by Na‐free (sucrose) medium was strongly inhibited by D‐600, tetracaine or divalent cations such as Co, Ni, Zn and Mg. The inhibition by Co was partially reversed by raising the concentration of Ca in the Na‐free medium. Secretion of CA from bovine isolated chromaffin cells was induced by Na‐deficient (sucrose) medium and was dependent on the concentrations of ionized Ca involved. All the Na substitutes tested increased secretion of CA and 45Ca uptake, in a parallel fashion. A correlation between secretion and 45Ca uptake was found under various experimental manipulations which reduced secretion of CA. These results demonstrated that unlike the perfused bovine adrenals, the Ca influx mechanism is essential for secretion by Na deprivation in the perfused cat adrenals as it is in bovine isolated chromaffin cells. It is suggested that Na deprivation increases Ca entry through the Ca channels by eliminating the competition between Na and Ca, and possibly by activating Ca influx linked with Na efflux.

show abstract

The effects of alkaline earths and other divalent cations on adrenal medullary secretion

Cited by 117 publications

References 15 publications

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca²⁺-Channel Modify Fusion-Pore Kinetics

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca²⁺-Channel Modify Fusion-Pore Kinetics

The role of the alkaline earth ions in anaphylactic histamine secretion

Exocytotic Secretion of Catecholamines From the Cat Adrenal Medulla by Sodium Deprivation: Involvement of Calcium Influx Mechanism

Contact Info

Product

Resources

About

The effects of alkaline earths and other divalent cations on adrenal medullary secretion

Cited by 117 publications

References 15 publications

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca2+-Channel Modify Fusion-Pore Kinetics

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca2+-Channel Modify Fusion-Pore Kinetics

The role of the alkaline earth ions in anaphylactic histamine secretion

Exocytotic Secretion of Catecholamines From the Cat Adrenal Medulla by Sodium Deprivation: Involvement of Calcium Influx Mechanism

Contact Info

Product

Resources

About

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca²⁺-Channel Modify Fusion-Pore Kinetics

Cations Residing at the Selectivity Filter of the Voltage-Gated Ca²⁺-Channel Modify Fusion-Pore Kinetics