Effects of prolonged exposure to histamine on guinea pig intestinal neurons.
Intracellular microelectrodes were used to study the effects of prolonged exposure to histamine on the electrophysiological behavior of AH/type-2 neurons in the myenteric plexus of the guinea pig small intestine. Application of histamine activated H2 receptors to convert the neurons to a heightened state of excitability. Heightened excitability was evident as repetitive spike discharge made possible, in part, by suppression of postspike after-hyperpolarization. The hyperexcitable state persisted unchanged for prolonged periods of 4.5 hr in the continued presence of histamine, suggesting that desensitization may never occur in vivo. The results are interpreted as a neural correlate for the pathophysiology associated with microscopic colitis and other inflammatory conditions involving mast cell hyperplasia.
Tamura
K
K
Department of Physiology I, School of Medicine, Tokai University, Isehara, Japan.
Wood
J D
JD
D000818:Animals; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D008297:Male; D008839:Microelectrodes; D009197:Myenteric Plexus / Q000166:cytology / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D011970:Receptors, Histamine H2 / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D011970:Receptors, Histamine H2; D006632:Histamine