Two kinds of modification by 5-methoxy-N,N-dimethyltryptamine of contractile responses to electrical stimulation of isolated guinea-pig vas deferens.

Reorganization of autonomic efferent pathways to the rat vas deferens was noted after chronic (30 days) sympathetic decentralization produced by hypogastric nerve (HGN) transection. In normal rats, electrical stimulation of the HGN elicited an increase in vasal pressure (VP) bilaterally, whereas pelvic nerve (PN) stimulation did not alter VP. However, after unilateral HGN transection, stimulation of the PN on the transected side but not on the normal side increased VP. The decentralized vas exhibited larger VP responses to stimulation of the contralateral HGN in comparison with the normal vas. After bilateral HGN transection, PN-induced VP responses were elicited at lower stimulus intensities than in rats with unilateral transections. PN-induced VP responses were blocked by hexamethonium and prazosin but were not altered by atropine. Distension of the vas lumen occurred after decentralization. PN-induced VP responses were not detectable in extremely distended vas. These data indicate that, after degeneration of sympathetic preganglionic axons, decentralized adrenergic ganglion cells are reinnervated by parasympathetic or sympathetic preganglionic pathways and that the reinnervation influences vasal function.

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Existence of postsynaptic dopamine D4 receptor as an enhancer of contractile responses to agonists in the guinea-pig vas deferens.

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)34251-9 ◽

1999 ◽

Vol 79 ◽

pp. 57

Author(s):

Hideji Morishita ◽

Takeshi Katsuragi

Keyword(s):

Guinea Pig ◽

Vas Deferens ◽

Dopamine D4 Receptor ◽

Contractile Responses ◽

D4 Receptor

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Innervation of enteric mast cells by primary spinal afferents in guinea pig and human small intestine

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00125.2014 ◽

2014 ◽

Vol 307 (7) ◽

pp. G719-G731 ◽

Cited By ~ 27

Author(s):

Guo-Du Wang ◽

Xi-Yu Wang ◽

Sumei Liu ◽

Meihua Qu ◽

Yun Xia ◽

...

Keyword(s):

Nervous System ◽

Mast Cell ◽

Small Intestine ◽

Electrical Stimulation ◽

Mast Cells ◽

Guinea Pig ◽

Mast Cell Protease ◽

Human Small Intestine ◽

Neurokinin 1 ◽

Stimulation Of

Mast cells express the substance P (SP) neurokinin 1 receptor and the calcitonin gene-related peptide (CGRP) receptor in guinea pig and human small intestine. Enzyme-linked immunoassay showed that activation of intramural afferents by antidromic electrical stimulation or by capsaicin released SP and CGRP from human and guinea pig intestinal segments. Electrical stimulation of the afferents evoked slow excitatory postsynaptic potentials (EPSPs) in the enteric nervous system. The slow EPSPs were mediated by tachykinin neurokinin 1 and CGRP receptors. Capsaicin evoked slow EPSP-like responses that were suppressed by antagonists for protease-activated receptor 2. Afferent stimulation evoked slow EPSP-like excitation that was suppressed by mast cell-stabilizing drugs. Histamine and mast cell protease II were released by 1) exposure to SP or CGRP, 2) capsaicin, 3) compound 48/80, 4) elevation of mast cell Ca2+ by ionophore A23187, and 5) antidromic electrical stimulation of afferents. The mast cell stabilizers cromolyn and doxantrazole suppressed release of protease II and histamine when evoked by SP, CGRP, capsaicin, A23187, electrical stimulation of afferents, or compound 48/80. Neural blockade by tetrodotoxin prevented mast cell protease II release in response to antidromic electrical stimulation of mesenteric afferents. The results support a hypothesis that afferent innervation of enteric mast cells releases histamine and mast cell protease II, both of which are known to act in a diffuse paracrine manner to influence the behavior of enteric nervous system neurons and to elevate the sensitivity of spinal afferent terminals.

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