The developing electrolytes concentrations of inner ear fluids in guinea pigs.Acta Otolaryngol. 1985 May-Jun; 99(5-6):525-8.AO
Cochlear endolymph, scala tympani perilymph, and scala vestibuli perilymph were collected from fetal, neonatal, and mature guinea pigs. The concentrations of Na and K in these fluids were then assessed using a microflame photometer. The electrolyte composition in the endolymph was already characterized by a high concentration of K and a low concentration of Na by the 49th day of gestation.