[Peripheral regulation of the adrenergic mediator process in the smooth muscles of the rat small intestine].
Under the effect of noradrenaline a physiologically active substance (A-factor) is released from smooth fibres of rat's intestine. A-factor enhances spontaneous activity of an isolated piece of rat's intestine. The A-factor is thermostable, its stimulating action is blocked neither with alpha- nor with beta-adrenolytics which indicates a non-catecholamine nature of this substance. Blocking of the intramural nervous system with novocain does not stop the release of the A-factor which shows that this system is not responsible for the A-factor release. Metabolic adrenoreceptors rather than the functional ones are responsible for the release of this substance. Experiments with metabolic poisons (2,4-dinitrophenol) and sodium fluoride have shown that the release of the A-factor is due to the effect of noradrenaline on glycolysis. The A-factor increases sensitivity of the intestine piece to noradrenaline. Participation of the A-factor in the regulation of the activity of smooth muscle adrenoreceptors of rat's intestine on the principle of positive feedback, is discussed.
D000818:Animals; D005246:Feedback; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000294:innervation*; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000294:innervation*; D018377:Neurotransmitter Agents / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D010525:Peripheral Nerves / Q000502:physiology*; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects / Q000502:physiology*
D018377:Neurotransmitter Agents; D011941:Receptors, Adrenergic; D009638:Norepinephrine
Perifericheskaia reguliatsiia adrenergicheskogo mediatornogo protsessa v gladkikh myshtsakh tonkoĭ kishki krysy.