Ultrastructure of rat initial collecting tubule. Effect of adrenal corticosteroid treatment.
Open Access
- 1 April 1985
- journal article
- research article
- Published by American Society for Clinical Investigation in Journal of Clinical Investigation
- Vol. 75 (4) , 1327-1334
- https://doi.org/10.1172/jci111833
Abstract
This study examines the effects of adrenalectomy and physiological replacement of mineralocorticoids and glucocorticoids on the cellular ultrastructure of the rat initial collecting tubule (late distal tubule). Animals were adrenalectomized (ADX) and for 10 d received by osmotic minipump either: vehicle, aldosterone (0.5 micrograms X 100 g-1 X d-1), aldosterone (2.0 micrograms X 100 g-1 X d-1), dexamethasone (1.2 micrograms X 100 g-1 X d-1), or aldosterone (0.5 micrograms X 100 g-1 X d-1) with dexamethasone (1.2 micrograms X 100 g-1 X d-1). Radioimmunoassay revealed that the low dose of aldosterone restored plasma aldosterone to control levels. The higher dose of aldosterone increased plasma levels by threefold. Morphometric techniques were used to measure membrane length of individual principal and intercalated cells in each condition. The basolateral membrane length of principal cells decreased by 35% in ADX animals. Low dose aldosterone replacement (0.5 micrograms X 100 g-1 X d-1) in ADX animals maintained membrane length at control values; at a higher level of aldosterone (2.0 micrograms X 100 g-1 X d-1) membrane length increased by 111% compared with control. Dexamethasone treatment, at a level that restored glomerular filtration rate to normal, had no effect on cellular ultrastructure. Combined aldosterone and dexamethasone replacement had no greater effect on basolateral membrane length than aldosterone alone. The length of the luminal membrane of the principal cell type was not affected by ADX or hormone treatment. Intercalated cell membrane length was not affected by ADX or hormone replacement. Thus, chronic aldosterone levels have an important, selective effect on the basolateral membrane of the principal cell. The correlation between these morphological results and the steroid hormone effects on renal electrolyte excretion, reported in the companion paper (15), suggests that basolateral membrane length is an important factor controlling the rate of sodium and potassium transport by the initial collecting tubule.This publication has 38 references indexed in Scilit:
- Renal potassium adaptation: Na-K-ATPase activity along the nephron after chronic potassium loadingAmerican Journal of Physiology-Renal Physiology, 1980
- Potassium Transport in the NephronAnnual Review of Physiology, 1979
- Modulation of cell membrane area in renal collecting tubules by corticosteroid hormones.The Journal of cell biology, 1979
- Renal potassium transport: contributions of individual nephron segments and populationsAmerican Journal of Physiology-Renal Physiology, 1978
- Mineralocorticoid effects on cation transport by cortical collecting tubules in vitroAmerican Journal of Physiology-Renal Physiology, 1978
- Transport characteristics of renal collecting tubules: influences of DOCA and dietAmerican Journal of Physiology-Renal Physiology, 1977
- Teleost chloride cell. I. Response of pupfish Cyprinodon variegatus gill Na,K-ATPase and chloride cell fine structure to various high salinity environments.The Journal of cell biology, 1976
- Separate effects of aldosterone, DOCA, and methylprednisolone on renal Na-K-ATPase,American Journal of Physiology-Legacy Content, 1974
- Response of the Distal Tubule and Cortical Collecting Duct to Vasopressin in the RatJournal of Clinical Investigation, 1973
- THE DEVELOPMENT OF SURFACE SPECIALIZATION IN THE SECRETORY EPITHELIUM OF THE AVIAN SALT GLAND IN RESPONSE TO OSMOTIC STRESSThe Journal of cell biology, 1969