Do mast cell degranulators release prostaglandins from frog atria?

Area of Science:

• Pharmacology
• Cardiovascular Physiology
• Histamine Research

Background:

• Isolated frog atria are sensitive to various stimuli.
• Mast cell degranulators can elicit physiological responses.
• Histamine, serotonin, and adrenergic pathways are involved in cardiac function.

Purpose of the Study:

• To investigate the mechanism of action of compound 48/80 and d-tubocurarine on frog atria.
• To explore the potential involvement of prostaglandins in these responses.

Main Methods:

• Isolated frog atria were treated with compound 48/80 and d-tubocurarine.
• Receptor blockers for H2-histamine, serotonin, and beta-adrenergic receptors were used.
• Experiments were conducted with indomethacin-treated atria (ex vivo and in vitro).

Main Results:

• Compound 48/80 and d-tubocurarine induced a delayed stimulation with tachyphylaxis and cross-tachyphylaxis.
• Blockade of H2-histamine, serotonin, and beta-adrenergic receptors did not inhibit the responses.
• Indomethacin treatment abolished the stimulant effects of mast cell degranulators.

Conclusions:

• A common indirect mechanism underlies the stimulatory effects of compound 48/80 and d-tubocurarine on frog atria.
• Prostaglandins likely play a role in mediating these responses.
• Further research is needed to elucidate the precise prostaglandin pathway involved.