Abstract
The variations in the O2-tension within the retina and in the corneoretinal standing potential of the eye in the rabbit and the cat were recorded simultaneously during anoxia and its following restoration stage. With regard to the two species of the cat and the rabbit the correlation between these variations were studied comparatively. The results obtained are summarized as follows:
1. Two characteristic variations are observed in the corneo-retinal standing potential of the eye as soon as the intra-ocular pressure is restored from its high levels (such as 200, 100 and 50mm Hg) to the normal (10mm Hg). The negative deflection of the variations was termed as N-wave and the positive deflection as P-wave. Both the trough time of the N-wave and the peak time of the P-wave were measured, and the values obtained were compared between cat and rabbit. It became evident that these times for the cat are shorter than those for the rabbit respectively.
2. In both species of the rabbit and the cat, the N-wave is generated in every case of restoration of the blood flow through the retina (due to normalization of the intra-ocular pressure). The generation of the N-wave is never caused by the variation in O2-tension within the blood flowing through the retina. On the other hand, the P-wave is generated differently between two species of the rabbit and cat, i. e. the P-wave for the cat frequently failed to appear, while the P-wave for the rabbit can be seen without fail. The generation of the P-wave for the rabbit may possibly be facilitated by a rapid increase in O2-tension within the blood, while this tendency can never be observed in the case of the cat.
3. The injection of isotonic NaCl solution into carotid artery with such a rate as 0.2ml per sec. causes a temporary increase in the corneo-retinal standing potential, but the injection with the rate slower than 0.05ml per sec. causes no variation in the corneo-retinal standing potential.
4. The adrenaline injected into the carotid artery causes two characteristic variations in the corneo-retinal standing potential which are similar in shape to the N- and P-wave respectively. Neither noradrenaline nor acetylcholine brings about such variations in the corneo-retinal standing potential as adrenaline does.
5. From the above mentioned results it is suggested that the generation of the N- and P-wave is most probably a consequence of the effect of adrenaline.
