A Histochemical Study on the Phosphatase of the Guinea-pigs Exposed to White Noise

Abstract

The author divided young guinea-pigs into 7 groups control group, V. B_1-, V. B_6-, V. B₁ B_6-, orotic acid-injection groups, group under 8% oxygen, group under 10% carbonic acid gas. The author stained the P-tase (alk. P-tase or acid P-tase) in the cochlea of the inner ear according to the modified Gomri's method exposing the animals to white noise of 100-105 phons for 5 hours every day during one to five weeks. Parallel to this he performed quantitative analyses of serum P-tase according to Fukuyama-Yamashita's method and of serum free aminoacids according to Yemm & Cocking's method, and examined carbohydrate metabolism of sensory tissues and made a conjecture upon acoustic mechanism from energy metabolism of an organism. The results obtained are as follows.
(1) P-tase is physiologically distributed in the cochlea of the guinea-pig, and is particularly found in the sensory tissues of hair cells, spiral ganglion cells etc. and in stria vascularis. Alk. P-tase in spiral ganglion cells is in some degree more deeply stained in the cytoplasm than in the nuclei, but acid P-tase is better stained in the nuclei. And in the hair cells both alk. and acid P-tase are more deeply stained in the nuclei than in the cytoplasm.
(2) P-tase in the cochlea is generally hard to stain perhaps owing to decalcification, and the dyeing of acid P-tase is unstable.
(3) Under the intense noise exposure alk. P-tase in the cochlea shows remarkable change previously to morphological change in the cells.
(4) The remarkable decrease of alk. P-tase in the cochlea can in some degree be prevented by the use of carbohydrate metabolism co-ferment (V. B₁) and protein metabolism co-ferment (V. B₆). V. B₁ was comparatively effective in single use, and the combined use of V. B₁ B₆ was also effective. Acid P-tase had generally the same tendency as alk. P-tase, but the details were unknown owing to its unstable staining property.
(5) The change of alk. P-tase is remarkable under low percentage of oxygen and high percentage of carbonic acid gas, and it is experimentally considered to be primarily necessary.
(6) The change of P-tase in the cochlea has the same tendency as that of serum P-tase. The serum alk. P-tase value of animals of noise exposure 2weeks, showed 16.2^mM/l (0.94) and that of the group of 4weeks exposure 6.6^mM/l (1.06), in contrast with the higher value of alk. P-tase of the n. rmal young guinea-pigs at 37.7^mM/l (acid P-tase: 2.52^mM/l). The remarkable decrease of alk. P-tase in the serum can in some degree be also prevented by the use of the co-fements (V. B₁, V. B₆). Accordingly it was found that intense noise influences metabolism of the whole body as well as the affected area.
(7) From the standpoint of the biochemical energy theory attributing energy sources of the nerve tissues to carbohydrate, the supply of P-tase (ATP, DPN etc) and V. B₁, the so-called ferments of glycogenesis, is considered to be primarily necessary to the activity of the sensory tissues as well as oxygen.
(8) Once the tissues suffer irreversible change by lack of oxygen and disturbance of fermentative metabolism, the restoration of the function is considered to be hopeless.
(9) Unless animals are under extreme loss of oxygen, Embden-Meyerhof Cycle is considered to be more intimately concerned with loss of metabolism than is generally supposed.