Adaptive expression pattern of different proteins involved in cellular calcium homeostasis in denervated rat vas deferens.
The activity and protein expression of plasma membrane and sarco(endo)plasmic reticulum (Ca2+-Mg2+)ATPases and ryanodine receptors were investigated in surgically denervated rat vas deferens. The function of thapsigargin-sensitive but not thapsigargin-resistant (Ca2+-Mg2+)ATPase (from sarco(endo)plasmic reticulum and plasma membrane, respectively), evidenced by enzyme activity and Ca2+ uptake experiments, was significantly depressed by 30-50% when compared to innervated vas. Western blots showed that such reduction in sarco(endo)plasmic reticulum (Ca2+-Mg2+)ATPase performance was accompanied by a decrement of similar magnitude in sarco(endo)plasmic reticulum (Ca2+-Mg2+)ATPase type 2 protein expression, without any significant change in plasma membrane (Ca2+-Mg2+)ATPase expression. Finally, [3H]ryanodine binding revealed that the density of ryanodine binding sites was reduced by 45% after denervation without modification in affinity. The present findings demonstrate that sarco(endo)plasmic reticulum proteins involved in intracellular calcium homeostasis are clearly down-regulated and brings further evidence of a modified calcium translocation in denervated rat vas deferens.
Quintas
Luis Eduardo M
LE
Departamento de Farmacologia Básica e Clínica, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-590, Rio de Janeiro, Brazil.
Cunha
Valéria M N
VM
Scaramello
Christianne B V
CB
da Silva
Cláudia L M
CL
Caricati-Neto
Afonso
A
Lafayette
Simone S L
SS
Jurkiewicz
Aron
A
Noël
François
F
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors*; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D003714:Denervation; D006706:Homeostasis; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000201:enzymology* / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D014649:Vas Deferens / Q000201:enzymology / Q000294:innervation* / Q000378:metabolism
D019837:Ryanodine Receptor Calcium Release Channel; D017301:Ca(2+) Mg(2+)-ATPase; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D002118:Calcium