ISSN:
1432-2013
Schlagwort(e):
Cytochromes
;
Kidney
;
Enzyme Induction
;
Aldosterone
;
Adrenalectomy
;
Cytochrome
;
Niere
;
Enzyminduktion
;
Aldosteron
;
Adrenalektomie
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary The influence of aldosterone in vivo on cytochromes in rat kidney mitochondria is studied, comparing rats in normal state, adrenalectomized state, and adrenalectomized rats 2 hours after administration of adlosterone (7.5 μg per 100 g rat as single dose plus infusion of 0.125 μg per hour and 100 g rat). No significant changes between these states are observed of either cytochrome b, cytochrome c1, or cytochrome c content. Cytochrome a, as estimated from the 605 mμ band of the difference spectrum (reduced vs. oxidized), decreases from 508±51 nanomoles per g protein (n=12) in the controls to 273±65 (n=12) nanomoles per g protein in the adrenalectomized state. After administration of aldosterone to adrenalectomized rats the concentration of cytochrome a increased to 464±38 nanomoles per g protein (n=12). The difference spectrum (anaerob vs aerob+Antimycin A) shows that the absorbancy maximum at 444 mμ (more specific for cytochrome a3) is also considerably decreased after adrenalectomy, and increased after administration of aldosterone to adrenalectomized rats. Hence the contents of both compounds of cytochrome oxidase, cytochrome a and cytochrome a3, appear to be controlled by aldosterone. The molar ratio of cytochrome c to cytochrome a is 1.1 in the controls, 1.8 after adrenalectomy, and 1.1 after administration of aldosterone to adrenalectomized rats. Possible relations of this effect to the previously observed increase of tricarboxylic acid cycle enzyme activities under aldosterone are discussed. The 46% decrease of the cytochrome a content in mitochondria from the whole kidney of adrenalectomized rats, which is restored to the normal level in response to aldosterone, is difficult to reconcile with the concept that the hormone acts on distal tubules only, as these constitute only about 10% of the material used. Therefore, the present result is considered to support the concept that the hormone acts on both distal and proximal tubules.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00592248
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