Cardiac mitochondrial calcium loading capacity is severely affected after chronic cholestasis in Wistar rats.
BACKGROUND
Cardiovascular changes correlated with some forms of hepatic disease are being reported in the literature.


OBJECTIVE
The aim of this work was to characterize cardiac mitochondrial bioenergetics and calcium buffering capacity in Wistar rats injected with six weekly doses of alpha-naphthylisothiocyanate (ANIT), a compound known to induce cholestasis in animal models.


METHODS
Isolated heart mitochondria were obtained from both injected and control animals and bioenergetic parameters were measured, as well as the capacity to buffer externally added calcium and the mitochondrial content of reduced protein thiol groups. Blood biochemistry analyses were obtained at the initial and end points of treatment. The in vitro ANIT effect on isolated heart mitochondria was also studied.


CONCLUSIONS
Our results showed that the respiratory control ratio was the only parameter affected in injected animals (p < .05, n = 5). Nevertheless, heart mitochondria from injected animals showed an inability to accumulate added calcium owing to an increased susceptibility to the calcium-dependent mitochondrial permeability transition (p < .0001, n = 5). The effects were still present 1 week after ending ANIT administration, when serum markers for liver injury and hyperbilirubinemia were already abated (although in the presence of bile duct proliferation). To our knowledge, this is the first time that cardiac mitochondrial calcium homeostasis and mitochondrial respiratory ratio are seen affected during ANIT-induced cholestasis, prevailing even in the absence of hepatic damage serum markers.
Oliveira
Paulo J
PJ
Dep. Zoologia, Faculdade de Ciências e Tecnologia, Centro de Neurociências de Coimbra de Coimbra, Universidade de Coimbra, Coimbra, Portugal.
Rolo
Anabela P
AP
Seiça
Raquel
R
Santos
Maria S
MS
Palmeira
Carlos M
CM
Moreno
António J M
AJ
D015058:1-Naphthylisothiocyanate / Q000633:toxicity; D000818:Animals; D001653:Bile Ducts, Intrahepatic / Q000187:drug effects / Q000473:pathology; D001774:Blood Chemical Analysis; D002118:Calcium / Q000378:metabolism*; D002779:Cholestasis / Q000097:blood / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D002908:Chronic Disease; D004195:Disease Models, Animal; D004734:Energy Metabolism; D005260:Female; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008564:Membrane Potentials / Q000187:drug effects; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D008933:Mitochondrial Swelling / Q000187:drug effects; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D007473:Ion Channels; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D015058:1-Naphthylisothiocyanate; D002118:Calcium