Zur Proteinkonzentration Der Meerschweinchen-Perilymphe

Abstract

The protein concentration of the guinea pig perilymph was investigated systematically using a micro-modification of the method of Lowry et al. Perilymph of scala vestibuli and of scala tympani was obtained from living animals and immediately post mortem by various methods. In living animals it is especially difficult to obtain samples without blood contamination. Another problem in the obtaining of perilymph from living animals is the contamination of tympanic perilymph samples with cerebrospinal fluid. This contamination diminishes the protein concentration of perilymph to a high degree. When the subarachnoid space is opened suboccipitally before perilymph extraction, there is no significant difference between protein content in tympanic and vestibular perilymph. The mean protein concentration in both cochlea scales is about 150 mg/100 ml. When samples are extracted post mortem from animals perfused intra-arterially, mean values of protein are in the same range. Without perfusion of animals, the mean value of tympanic samples extracted post mortem is significantly higher. Causes of artefacts in perilymph investigations are discussed.

A dual wedge microneedle for sampling of perilymph solution via round window membrane

“…The value of 1.74 mg/mL falls within the range of literature values:1.50 (31) and 2.757 ± 0.238 mg/mL (5). Although, the biochemical analysis is not the goal of this study, the protein constituents of sampled solution can be analyzed and identified via LC-MS/MS (32,33).…”

Total magnesium concentrations of perilymph, cerebrospinal fluid and blood in guinea pigs fed different magnesium-containing diets

“…The slight Mg difference between the PL specimens sampled separately from the scala tympani (0.71 mmol/l) and scala vestibuli (0.65 mmol/l) is probably due to a contamination of the scala tympani samples with CSF, which has a higher Mg level than PL. Contamination of PL with CSF during sampling has proved to be the major problem in analytical studies of PL [3,9,20,21]. Although in this study the CSF pressure was also substantially relieved before the sampling of PL to minimize the danger of contamination with CSF via the cochlear aqueduct, the CSF problem may not have been entirely Correlation between the Mg concentrations measured in the plasma, cerebrospinal fluid (CSF) and perilymph (PL) of anesthetized guinea pigs.…”

“…Venous blood (30-40 µl) was collected from an ear vein and centrifuged to separate serum. CSF (10-15 µl) was taken by puncturing the atlanto-occipital membrane, which was then widely opened in order to relieve the CSF pressure effectively prior to PL sampling [20,21]. PL of the scala tympani and scala vestibuli (3-5 µl from each scala of one cochlea) was carefully aspirated through a small hole drilled into the bone of both basal scalae after perforation of the helicotrema, using fine-tipped, siliconized glass capillaries connected to a micropiston burette via water-filled capillary tubing [19].…”

“…The purpose of the present study was therefore to determine the total Mg concentrations of PL, CSF and plasma in anesthetized guinea pigs fed a standard diet with an adequate Mg content. Due consideration was given to the risk of contamination of PL with CSF, which is the major problem in the analytical investigation of PL, as demonstrated in our [3,20,21] and other [9] previous studies.…”