Acute moderate hyponatraemia and its rapid correction: effects on striatal and pontine ultrastructure in an animal model of the TURP syndrome.
OBJECTIVE
To investigate the effects of moderate hyponatraemia, induced by intravenous application of an electrolyte-free irrigation fluid, as a model of the human transurethral prostate resection syndrome and of its rapid correction by hypertonic saline infusion in rats.


METHODS
Experimental animals received irrigation fluid (Purisole SM) 20 mL kg(-1) body weight, intravenously. In one group, hyponatraemia was subsequently rapidly corrected by infusion of hypertonic saline (NaCl 5.85%), while rats of group two were 'sham-corrected' by infusion of a balanced salt crystalloid solution. Plasma sodium concentrations were analysed during and at the end of the experiments. After 10 days, experimental and untreated control animals were killed humanely, fixed by perfusion and the brains were prepared for electron microscopic investigation of myelin sheets and glial cell numbers in the striatum and pons.


RESULTS
The myelin appearance was unaltered in experimental groups compared to controls, but glial cell numbers were distinctly altered in the pons but not in the striatum. In the pons, oligodendrocytes were significantly reduced in number upon rapid correction of hyponatraemia, while astrocyte numbers were increased in rats with uncorrected hyponatraemia.


CONCLUSIONS
Our electron microscopic data demonstrate that the effects of hyponatraemia and of its rapid correction are multifarious in animals. This may also apply for human patients during transurethral prostate resection.
Reuss
S
S
Johannes Gutenberg-University, Department of Anatomy, School of Medicine, Mainz, Germany. reuss@uni-mainz.de
Bürger
K
K
Claus
H
H
Reinhardt
T
T
Disque-Kaiser
U
U
Depta
A L
AL
David
M
M
Gervais
H W
HW
D000818:Animals; D001253:Astrocytes / Q000648:ultrastructure; D002452:Cell Count; D003342:Corpus Striatum / Q000648:ultrastructure*; D000077324:Crystalloid Solutions; D004195:Disease Models, Animal; D007010:Hyponatremia / Q000473:pathology* / Q000628:therapy; D007275:Injections, Intravenous; D007552:Isotonic Solutions; D008297:Male; D008353:Mannitol / Q000008:administration & dosage; D008854:Microscopy, Electron; D009186:Myelin Sheath / Q000648:ultrastructure; D009457:Neuroglia / Q000648:ultrastructure; D009836:Oligodendroglia / Q000648:ultrastructure; D010952:Plasma Substitutes / Q000627:therapeutic use; D011149:Pons / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015532:Rehydration Solutions / Q000627:therapeutic use; D012462:Saline Solution, Hypertonic / Q000627:therapeutic use*; D012964:Sodium / Q000097:blood; D013012:Sorbitol / Q000008:administration & dosage; D013577:Syndrome; D020728:Transurethral Resection of Prostate / Q000009:adverse effects*
D000077324:Crystalloid Solutions; D007552:Isotonic Solutions; D010952:Plasma Substitutes; D015532:Rehydration Solutions; D012462:Saline Solution, Hypertonic; D008353:Mannitol; D013012:Sorbitol; D012964:Sodium