To elucidate the argument on the hypertensive effect of repeated stress, morphological study on the juxtaglomerular apparatus of pain-stressed mice was carried out. Following the repeated stress on mice by subcutaneous injections of formalin every day, animals were sacrificed on 1, 3, 6, 12 hours and 1, 2, 3, 6 days after the 5th injection. Kidneys fixed in 10%, Zenker-formol solution were routinely processed, and 4um sections were stained by Bowie's stain. For the precise interpretation, following protocols were applied; Comparing the amount of secretory granules, juxtaglomerular granulation index (JGI) was weighted on every 1000 glomeruli according to their granulaities. Comparing the proportional appearance of juxtaglomerular apparatus, granulation cell index (GCI) was counted as a mean number of granular juxtaglomerular apparatus among every 100 glomeruli. Comparing the cellularities of a single juxtaglomerular apparatus, juxtaglomerular granular cell count (JGCC) was counted as a mean number of granular juxtaglomerular cells appearing in a longitudinally. sectioned afferent arteriole. Comparing the functional relationship between the juxtaglomerular cells and macula densa cells, macula densa cell count (MD count) was counted as the mean number of macular densa cells having contacts with granular juxtaglomerular cells. Result of this experiment was processed and interpreted as followings. 1. Repeated pain-stress give rise to the prominant effect to juxtaglomerular cells, as high as double granular amount as compared to normal one, during 3-6 hours after the last stress. 2. Functional relationship between the distal convoluted tubule and Juxtaglomerular cells, checked out by MD contacts, was also highest during 3 to 6 hours term. 3. The effects were decreased afterwards, but still most counts were higher than those of normal data until 6th day, the last term of this experiment. 4. Present study show that the repeated pain-stress initiate the significant pressure-rising effect to animals during the first day after the last stress, and these effects may be latent during some days afterwards. 5. As the precise mechanism involved in this aspect remains to be elucidated, further studies includingelectron microscopic and histochemical methods shall be suggested.
Animals ; Arterioles ; Cell Count ; Formaldehyde ; Injections, Subcutaneous ; Juxtaglomerular Apparatus ; Kidney ; Mice* ; Secretory Vesicles