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VARIATIONS IN KALLIKREIN‐LIKE ESTERASE ACTIVITY IN DIFFERENT SEGMENTS OF THE RAT NEPHRON DURING SALT‐LOAD AND SALT‐DEPLETION
Author(s) -
Kimura Kenjiro
Publication year - 1983
Publication title -
acta pathologica microbiologica scandinavica series a :pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0108-0164
DOI - 10.1111/j.1699-0463.1983.tb02725.x
Subject(s) - salt (chemistry) , nephron , kallikrein , esterase , chemistry , biology , medicine , endocrinology , biochemistry , enzyme , kidney
Histochemical changes in kallikrein‐like activity in the rat nephron induced by chronic salt‐load or saltdepletion were investigated semiquantitatively, using a synthetic substrate for kallikrein, pro‐phe‐argnaphthylester. The location of the changes in the different segments of the nephron was established by comparison with neighbouring freeze‐dried sections, where the various structures of the tubular segments were identified. The enzyme activity was graded semiquantitatively and the percentage of tubular segments possessing enzyme ectivity was recorded. In salt‐loaded rats , the enzyme activity in the deep half of the renal cortex was decreased in the first and second segments of the proximal tubule as well as in the third segment in the cortex. In salt‐depleted rats , the enzyme activity in the deep half of the renal cortex was also decreased in the first segment of the proximal tubule as well as in the third segment in the cortex. In contrast, the enzyme activity in the second segment of the proximal tubule was increased in the superficial cortex as well as in the deep cortex. Furthermore, in the salt‐depleted rats the enzyme activity was decreased in the cortical part of the ascending thick limb of Henle, but increased in the medullary part. In the superficial part of the cortex, the enzyme activity was decreased in the distal convoluted tubule. In the kidneys from both salt‐loaded and salt‐depleted rats, the differences in enzyme activity between zones ‐ such as found in the normal kidney ‐ disappeared in the case of the first and second segments of the proximal tubule. However, in the other segments of the nephron, the zonal differences were preserved in both experimental conditions.