Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:P21817 (
RyR1
)
1,154
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In the current study, the potential contributions of ryanodine receptors (RyRs) to intrinsic pumping and responsiveness to substance P (SP) were investigated in isolated rat mesenteric collecting
lymphatic vessels
. Responses to SP were characterized in
lymphatic vessels
in the absence or presence of pretreatment with nifedipine to block L-type Ca
2+
channels, caffeine to block normal release and uptake of Ca
2+
from the sarcoplasmic reticulum, ryanodine to block all RyR isoforms, or dantrolene to more selectively block
RyR1
and RyR3. RyR expression and localization in lymphatics was also assessed by quantitative PCR and immunofluorescence confocal microscopy. The results show that SP normally elicits a significant increase in contraction frequency and a decrease in end-diastolic diameter. In the presence of nifedipine, phasic contractions stop, yet subsequent SP treatment still elicits a strong tonic contraction. Caffeine treatment gradually relaxes lymphatics, causing a loss of phasic contractions, and prevents subsequent SP-induced tonic contraction. Ryanodine also gradually diminishes phasic contractions but without causing vessel relaxation and significantly inhibits the SP-induced tonic contraction. Dantrolene treatment did not significantly impair lymphatic contractions nor the response to SP. The mRNA for all RyR isoforms is detectable in isolated lymphatics. RyR2 and RyR3 proteins are found predominantly in the collecting lymphatic smooth muscle layer. Collectively, the data suggest that SP-induced tonic contraction requires both extracellular Ca
2+
plus Ca
2+
release from internal stores and that RyRs play a role in the normal contractions and responsiveness to SP of rat mesenteric collecting lymphatics.
NEW & NOTEWORTHY
The mechanisms that govern contractions of
lymphatic vessels
remain unclear. Tonic contraction of
lymphatic vessels
caused by substance P was blocked by caffeine, which prevents normal uptake and release of Ca
2+
from internal stores, but not nifedipine, which blocks L-type channel-mediated Ca
2+
entry. Ryanodine, which also disrupts normal sarcoplasmic reticulum Ca
2+
release and reuptake, significantly inhibited substance P-induced tonic contraction. Ryanodine receptors 2 and 3 were detected within the smooth muscle layer of collecting
lymphatic vessels
.
...
PMID:Evidence of functional ryanodine receptors in rat mesenteric collecting lymphatic vessels. 3127 55
