In the chinchilla, quantitative changes in strial thickness, area of the endolymphatic space, serum osmolality, and serum levels of glycerol, glucose, total protein sodium, potassium and chloride were determined at 1, 2, 3 and 5 h after the intraperitoneal administration of 6 g/kg glycerol. The serum osmolality, glycerol, glucose and potassium levels increased, while serum sodium and chloride decreased. Quantitative changes in cochlear structure included an increase in strial thickness and a decrease in area of the endolymphatic space. In all the animals (n=50), the increase in strial thickness was closely correlated (correlation coefficient r=0.57) to an increase in serum osmolality. This correlation with strial thickness improved (R=0.71) when the interval between injection and animal sacrifice was used in combination with serum osmolality. The increase in stria thickness was also closely correlated to an increase in serum glycerol and to a decrease in serum chloride. A decrease in endolymphatic volume was found most consistently at 3 h after the i.p. administration of glycerol.
Bibliographical noteFunding Information:
This work was supported by NINCDS grants NS04615 and NS12125, The Deafness Research Foundation and the Research Fund of the American Otological Society.
- Endolymph volume
- Osmotic diuretic
- Stria vascularis