Effects of Dibutyryl Cyclic AMP on contractile Performance of Isolated Heart Muscle Depressed by Thiamylal and Halothane

Iwatsuki, Naofumi; Iwatsuki, Kazuhiko

doi:10.1620/tjem.113.357

Cited by 6 publications

(4 citation statements)

References 5 publications

(2 reference statements)

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“…Sprague et al have suggested that halothane inhibits phenylephrine-induced aortic contraction by stimulating cAMP formation (23). The myocardial depressive effects of halothane and the barbiturate thiamylal on isolated dog myocardium can be reversed by exogenous dibutyryl cAMP, further suggesting that the site of action of these agents occurs before cAMP's effect (24). Triner et al (25) have recently demonstrated halothane-induced activation of adenylate cyclase in bronchial and uterine smooth muscle.…”

Section: Inhibition Of Water Flow By General Anesthetics 985mentioning

confidence: 99%

Selective inhibition of osmotic water flow by general anesthetics to toad urinary bladder.

Levine¹,

Levine²,

Worthington³

et al. 1976

J. Clin. Invest.

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A B S T R A C T Vasopressin increases the permeability of the totad urinary bladder, an analogue of the mammalian renal collecting duct, to water and small solutes, especially the amide urea. We have observed that three general anesthetic agents of clinical importance, the gases methoxyflurane and halothane and the ultrashortacting barbiturate methohexital, reversibly inhibit vasopressin-stimulated water flow, but do not depress permeability to urea, or to the lipophilic solute diphenylhydantoin.In contrast to their effects in vasopressin-treated bladders, the anesthetics do not inhibit cyclic AMP-stimulated water flow, consistent with an effect on vasopressin-responsive adenylate cyclase. The selectivity of the anesthetic-induced depression of water flow suggests that separate adenylate cyclases and cyclic AMP pools may exist for control of water and urea permeabilities in the toad bladder. Furthermore, theophylline's usual stimulatory effect on water flow, but not its effect on urea permeability, was entirely abolished in methoxyfluranetreated bladders, suggesting that separate phosphodiesterases that control water and urea permeabilities are present as well.We would conclude that the majority of water and urea transport takes place via separate pathways across the rate-limiting luminal membrane of the bladder cell, and that separate vasopressin-responsive cellular pools of cyclic AMP appear to control permeability to water and to urea. INTRODUCTIONThere is evidence in several epithelial tissues that water and small amides such as urea cross the cell membrane via independent pathways. In the toad urinary bladder, for example, vasopressin-stimulated urea transport is blocked by agents such as phloretin, tannic acid, and the oxidizing agents permanganate and chromate, while osmotic water flow is unaltered (1-3). These inhibitory agents appear to act at a luminal membrane site, beyond the generation of cyclic AMP, since cyclic AMPstimulated urea transport is inhibited as effectively as transport stimulated by vasopressin (3).The present study describes the action of three anesthetic agents, the gases methoxyflurane and halothane and the short-acting barbiturate methohexital, which have an effect opposite to that of phloretin and the oxidizing agents; the inhibition of osmotic water flow with no alteration in urea transport. In contrast to the selective inhibitors of urea transport, the anesthetics do not inhibit cyclic AMP-stimulated water movement. This suggests that the independent pathway for xvater movement may involve not only a separate site for penetration at the luminal membrane, but a specific and separate adenylate cyclase-cyclic AMP-mediated control system as well.

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Section: Inhibition Of Water Flow By General Anesthetics 985mentioning

confidence: 99%

Selective inhibition of osmotic water flow by general anesthetics to toad urinary bladder.

Levine¹,

Levine²,

Worthington³

et al. 1976

J. Clin. Invest.

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show abstract

“…A similar finding was observed in dibutyryl cyclic AMP (Iwatsuki and Iwatsuki 1974). Since a positive inotropic effect of dibutyryl cyclic AMP is considered to be due to increased Ca++ available to the myofibrils in the sarcoplasm (Robinson et al 1965;Entman et al 1969; Drummond and Hemm ings 1972), the mechanisms related to Ca++ in contraction may be responsible to and Halothane and Myocardial Contractility 7…”

Section: Discussionmentioning

confidence: 56%

“…It has been also recognized that a positive inotropic effect of catecholamines (Langer 1973) or an increase in the frequency of stimulation (Grossman and Furchgott 1964;Teiger and Farah 1967) is closely related to the intracellularly increased Ca++ concentration of the myocardium. Previously we reported that, in the isolated dog heart muscle, the depression of myocardial contractility produced by thiamylal was easily reversed by dibutyryl cyclic AMP, while the depression produced by halothane resisted the counteraction of this agent (Iwatsuki and Iwatsuki 1974). It was also reported that the myocardium depressed by thiamylal or halothane showed a positive staircase phenomenon in contractility following an increase in the frequency of stimulation (Iwatsuki and Iwatsuki 1975).…”

mentioning

confidence: 94%

Effects of change in concentration of calcium on myocardial contractility depressed by thiamylal and halothane.

Iwatsuki

1976

Tohoku J. Exp. Med.

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“…Krishna and Paradise (1972) have reported that pyruvate administered into the bathing medium reverses the myocardial depression produced by halothane, but it is ineffective for the reversal of depression produced by pentobarbital. Recently we have demonstrated in isolated heart muscle that the myocardial depression produced by thiamylal is reversed readily by dibutyryl cyclic AMP, but the depression produced by halothane resists to the antagonizing effect of this agent (Iwatsuki and Iwatsuki 1974) . These two findings suggest that the mechanism of myocardial depression may be different between thiamylal and halothane.…”

mentioning

confidence: 99%

Effects of Dibutyryl Cyclic AMP on contractile Performance of Isolated Heart Muscle Depressed by Thiamylal and Halothane

Cited by 6 publications

References 5 publications

Selective inhibition of osmotic water flow by general anesthetics to toad urinary bladder.

Selective inhibition of osmotic water flow by general anesthetics to toad urinary bladder.

Effects of change in concentration of calcium on myocardial contractility depressed by thiamylal and halothane.

Effects of change in frequency of stimulation on myocardial depression produced by thiamylal and halothane.

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