The Mucinate Content of Saliva.

Abstract

The method used for the determination of the mucinate content was the nephelometric procedure described by Inouye, 1 as follows: A 10 cc. sample of saliva is made alkaline with 2.5 cc. of 5% NaOH, thoroughly mixed, and promptly filtered through a dry filter. Five cc. of the filtrate, in a collodion bag, is dialyzed against running water until no longer alkaline to phenolphthalein (but still alkaline to litmus), and then against several changes of distilled water. The contents of the bag are then transferred to a 50 cc. volumetric flask and diluted to volume, of which 20 cc. are then treated with 0.02 N HCl from a burette, drop by drop, until an additional drop fails to give more precipitate. This is then compared nephelometrically with a standard solution of Na mucinate solution prepared as follows: A 10 cc. sample of 0.1% Na mucinate solution is dialyzed (if the mucinate is completely soluble in water without the addition of NaOH, the dialysis is omitted), and made up to 50 cc., of which 20 cc. are then titrated to maximum turbidity. If the standard and unknown give widely divergent readings, appropriate dilution of one of them should be made to bring the readings closer together.

The mechanical stimulation of chewing paraffin was used to obtain the “controls”. Twenty minutes after the end of collection of a control sample, the mechanical stimulus was again applied or a chemical stimulus with a few drops of lime juice or crystals of rocksugar on the tongue (in these cases the first expectorations were discarded), or the smoking of a cigarette, and a new sample collected for analysis. Twenty-six samples, from 9 subjects, under the mechanical stimulation, were analyzed.