Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this series of studies, the innervation patterns of whole-mount preparations of bicuspid and tricuspid valves were studied by light microscopy in the mouse, rat, guinea pig, and opossum. The acetylcholinesterase-positive networks of nerve fibers showed many similarities in the basic patterns of valve innervation in all of the species studied, but several interspecies variations were observed. The basal zone of the valve adjacent to the fibromuscular atrioventricular ring displayed the most dense plexus of nerves, with acetylcholinesterase-positive fibers being seen across the width of the valve. In the intermediate zone of the valve, less dense plexuses of nerve fibers were found; and these were more numerous in the cuspal areas and less numerous in the intervening commissural areas. In the distal portions of the valve, nerve networks arborized extensively, with some of their nerve fibers extending toward the chordae tendineae and the free edges of the valve cusps. Only in the guinea pig and opossum did these fibers reach the free margin of the valve cusp, where they either ended directly as free nerve endings or lay parallel to the free edge of the cusp, often running between adjacent chordae tendineae. Although the patterns of innervation were similar in both bicuspid and tricuspid valves, the innervation density of the bicuspid valve was greater than that of the tricuspid valve for each species examined. A distinguishing feature of guinea pig and opossum tricuspid valves was that their chordae tendineae were relatively more prominent and more densely innervated than the bicuspid chordae tendineae. Free nerve endings with no light microscopic evidence of specialization were present throughout the bicuspid and tricuspid valves of all species studied. Some nerve endings in the opossum showed evidence of specialization, with brush-like arborizations leading to presumed free terminals seen chiefly in the distal zone of the valve cusps. Although some general tendencies were apparent, we have demonstrated that interspecies heterogeneity exists in the terminal networks of the atrioventricular valves of mouse, rat, guinea pig, and opossum.
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PMID:Variations in atrioventricular valve innervation in four species of mammals. 230 Dec 79

The sensitivity to capsaicin of substance P-immunoreactive nerve fibres in the hearts of guinea-pigs was examined. Capsaicin decreased considerably the substance P-immunoreactive material in nerve fibres of the parietal pericardium, atria, bicuspid and tricuspid valves. Pericardial and valvar nerve fibres localized by acetylcholinesterase (AChE) histochemistry had a distribution and density pattern similar to that of the substance P immunoreactive fibres. Capsaicin treatment also decreased the number of visible AChE-positive nerve fibres. It is known that capsaicin has a selective action on those substance P-immunoreactive fibres that are of sensory origin; thus, these results imply that substance P-immunoreactive fibres in the heart are sensory. Moreover, the results suggest that some of the nerve fibres localized in the heart by AChE histochemistry are substance P-containing sensory fibres.
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PMID:Depletion by capsaicin of substance P-immunoreactivity and acetylcholinesterase activity from nerve fibres in the guinea-pig heart. 617 21

The objective of this study was to determine whether and to what extent age-related changes occur in atrioventricular (AV) heart valve innervation. The AV valves from three young adult (3 months) and three older (> 24 months) female guinea pigs were studied. An acetylcholinesterase (AChE) localization method was used to prepare valve whole mounts for analysis. Two methods were used to assess nerve fiber density. Segments of the valves were drawn using a camera lucida/Nikon optiophot system. The density of nerve fibers was calculated from digitized images. The density of nerve fibers was also calculated by counting the points at which the nerve plexus intersected with the grid lines of an ocular graticule. In the bicuspid and tricuspid valves of the older guinea pigs, we observed a marked diminution in the densities of the nerve plexus, particularly in the basal zone, towards the free edges of the valve cusps, and in the chordae tendineae. Whole mount preparations such as those used in our morphological studies of the AV innervation may assist in elucidating the changes in other autonomic nerve plexuses with aging. Further work is required to establish whether and to what extent the loss of valve innervation influences the effectiveness of closure of the valves.
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PMID:The terminal innervation patterns in young and old guinea pig heart valves: a quantitative analysis using acetylcholinesterase staining. 753 Feb 10