Postnatal maturation of the rabbit cortical collecting duct

Lisa M. Satlin, Andrew Evan, Vincent H. Gattone, George J. Schwartz

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

The mature, fully differentiated cortical collecting duct plays a major role in the final renal regulation of Na+, K+ and H+ transport. To characterize the growth of this segment, we measured the outer diameter and the dry weight of cortical collecting ducts isolated from newborn, 1-month-old, and adult rabbits. During the 1st month of life no significant changes were observed; however, there was a 60% increase in both parameters after the 4th week of life. Growth-related accretion of K+ was demonstrated by showing tubular K+ content to increase by 60% with maturation. Concomitant with the increase in tubular size, total cell number per millimeter of tubular length rose by 30%. Approximately 50% of the observed increment in tubular size could be accounted for by cell hyperplasia, with the remaining increase resulting from cell hypertrophy. Hypertrophy of principal cells was confirmed by scanning electron microscopy, which demonstrated a doubling of the circumferential width without any change in longitudinal length. Hyperplasia was confirmed, using a fluorescent chromatin stain, by our finding of a mitotic frequency of 3/1000 cells in the neonatal mid-cortical collecting duct; the observed number of mitoses was 10-fold higher at the most cortical end (ampulla). The number of intercalated cells per millimeter of tubule length, identified by bright green fluorescence after cortical collecting ducts were stained with 6-carboxyfluorescein diacetate, was found to double during maturation, the increase being significant only after the 4th postnatal week. We conclude that maturation of the mid-cortical collecting duct results from both cellular hyperplasia and hypertrophy. It is unlikely that this segment plays a major role in regulating Na+, K+, and H+ transport in the neonatal kidney.

Original languageEnglish
Pages (from-to)135-145
Number of pages11
JournalPediatric Nephrology
Volume2
Issue number1
DOIs
StatePublished - Mar 1988

Fingerprint

Hypertrophy
Rabbits
Hyperplasia
Cell Count
Kidney
Growth
Mitosis
Electron Scanning Microscopy
Chromatin
Coloring Agents
Fluorescence
Weights and Measures
6-carboxyfluorescein diacetate

Keywords

  • Cortical collecting duct
  • Helium glow photometry
  • Mitosis
  • Potassium
  • Quartz fiber balance
  • Scanning electron microscopy
  • Transmission electron microscopy

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Nephrology

Cite this

Postnatal maturation of the rabbit cortical collecting duct. / Satlin, Lisa M.; Evan, Andrew; Gattone, Vincent H.; Schwartz, George J.

In: Pediatric Nephrology, Vol. 2, No. 1, 03.1988, p. 135-145.

Research output: Contribution to journalArticle

Satlin, Lisa M. ; Evan, Andrew ; Gattone, Vincent H. ; Schwartz, George J. / Postnatal maturation of the rabbit cortical collecting duct. In: Pediatric Nephrology. 1988 ; Vol. 2, No. 1. pp. 135-145.
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