AJP - Endo AJP: Cell Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab 265: E121-E127, 1993;
0193-1849/93 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Felix, R.
Right arrow Articles by Cota, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Felix, R.
Right arrow Articles by Cota, G.

AJP - Endocrinology and Metabolism, Vol 265, Issue 1 E121-E127, Copyright © 1993 by American Physiological Society

ARTICLES

Comparison of lactotrope subtypes of neonatal and adult male rats: plaque assays and patch-clamp studies

R. Felix, J. Horta and G. Cota
Department of Physiology, Biophysics, and Neurosciences, Centro de Investigaciony de Estudios Avanzados, Mexico City DF, Mexico.

We examined the differences in lactotrope number and function between pituitary cultures from neonatal (10-day-old) and adult male rats. Basal hormone release was measured with the reverse hemolytic plaque assay. Whole cell Ba2+ currents through Ca2+ channels were recorded from identified prolactin (PRL) secretors with the patch-clamp technique. Lactotropes were classified in two groups according to the relative amount of PRL released: small-plaque (SP) secretors accounted for 6% of all cells in both neonatal and adult pituitary cultures, whereas large-plaque (LP) secretors comprised 13% of the adult pituitary cells but were scarce in cultures from neonates. Simultaneous plaque assays for PRL and growth hormone (GH) showed that in adults as well as in neonates the number of SP and LP secretors was similar to the number of lactosomatotropes (PRL cells that also release GH) and classical lactotropes (PRL-only cells), respectively. Ba2+ current density at positive membrane potentials was markedly higher in adult LP secretors than in neonatal or adult SP lactotropes. We conclude that the appearance of LP secretors constitutes a major postnatal change within the rat lactotrope population. These cells present a large activity of high-threshold Ca2+ channels in the plasma membrane, release PRL at high basal rates, and may correspond to classical lactotropes. The results further suggest that neonatal lactotrope-like cells persist during development and give place to adult SP secretors.


This article has been cited by other articles:


Home page
 J. Neurosci.Home page
H. Liu, R. Felix, C. A. Gurnett, M. De Waard, D. R. Witcher, and K. P. Campbell
Expression and Subunit Interaction of Voltage-Dependent Ca2+ Channels in PC12 Cells
J. Neurosci., December 1, 1996; 16(23): 7557 - 7565.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online