Effects of the hormone of the salivary glands on the protein metabolism

Abstract

From the data obtained by clinical observations, Takaoka assumed that salivary glands took a part in protein metabolism. Takaoka and co-workers observed that extirpation of the salivary glands caused a decrease of the serum A/G ratio in dogs, and that this change was not recognized in dogs with in which external fistulas of salivary gland was made.To make a further investigation on this mechanism, the effect of the hormone of the salivary glands (Parotin) on the protein metabolism was observed in rats and rabbits.Following was the results obtained. First report : (Effect of Parotin on urea and amino acid nitrogen levels in the blood of rats)1.The growth of young rats which were given Parotin (1mg/kg) was much more rapid that of those which were given physiological saline solution.2.Urea and amino acid nitrogen in the blood of rats which were given physiological saline solution showed a gradual increase, while the reverse was observed in rats which were given Parotin.3.Oral administration of casein bydrolysates suppressed the elevation of urea and amino acid nitrogen levels in the blood of rats which were given Parotin, while this was not observed in controls.4.Parotin caused a decrease of urea nitrogen in the blood of rats in which bilateral kidneys were removed.Second report : (Studies using radioactive isotopes)1.After oral administration of glycine-1-C14, the maximum incorporation to the liver protein was usually seen at sixth hour. This was accelerated by 20 per cent when rats were given Parotin. However, incorporation rate was almost same between Parotin group and controls 24 hours after the time of administration.2.Turnover rate of phosphorus in ribonucleic acid in the liver observed by using radioactive P32 was much more accelerated in rats which were given Parotin compared with controls which were given physiological saline solution. This was also true in the turnover rate of desoxy-ribonucleic acid in the bone marrows.3.Unlike Parotin, bovine serum globulin did not show any influence on the turnover rate of ribo-nucleic acid in the liver of rats, its effect being same with physiological saline solution.