Subject(s)
Anti-Inflammatory Agents/pharmacology , Bronchi/drug effects , Dexamethasone/pharmacology , Trachea/drug effects , Animals , Bronchi/innervation , Bronchi/physiology , Drug Antagonism , Electric Stimulation , Histamine/pharmacology , In Vitro Techniques , Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Muscle, Smooth/innervation , Muscle, Smooth/physiology , Nerve Fibers/physiology , Rats , Trachea/innervation , Trachea/physiologyABSTRACT
Histamine produced either a bronchodilation or a bronchoconstriction in rats. In a 0.01-1.0 mcg/ml concentration histamine augmented the contractions amplitude in electrical stimulation of the trachea, in a 10-100 mcg/ml concentration histamine enhances the muscle tone thus decreasing the induced contractions. The histamine effects seems to be connected with its prevailing influence on different structures of the airways depending on the concentration. Its high concentrations act directly on the smooth muscle whereas its lower concentration affects receptors signaling the functional modules of the metasympathetic nervous system within the intramural ganglia of the trachea.
Subject(s)
Histamine/physiology , Respiratory Physiological Phenomena , Animals , Electric Stimulation , Histamine/pharmacology , In Vitro Techniques , Muscle Contraction , Muscle, Smooth/drug effects , Muscle, Smooth/innervation , Muscle, Smooth/physiology , Nerve Fibers/physiology , Rats , Respiratory Physiological Phenomena/drug effects , Trachea/drug effects , Trachea/innervation , Trachea/physiologyABSTRACT
Histamine was shown to exert various effects upon respiratory pathway wall's structures in rats. Glucocorticoids were shown to inhibit an increase in intracellular calcium induced by histamine. This investigation involved study of the interaction mechanisms between histamine and dexamethasone, on one hand, and intramural neural structures, on the other hand.
