Ionophore A23187 partially reverses LH secretory defect of pituitary cells from old rats

R. S. Chuknyiska, Marc R. Blackman, G. S. Roth

Research output: Contribution to journalArticle

Abstract

We measured in vitro release of luteinizing hormone (LH) in the presence of 1.5 mM extracellular calcium, with and without LH-releasing hormone (LHRH) 10-10 to 10-7 M) or the ionophore A23187 (10-7 to 10-4 M), in primary cultures of anterior pituitary cells from intact mature (6 mo) and old (24 mo) male and intact and ovariectomized mature and old female Wistar rats. Base-line as well as LHRH- and A23187-mediated LH secretion was decreased from cells of old rats. However, exposure to A23187 led to a nearly twofold greater augmentation of LH release from cells of old rats, thus decreasing the apparent age-related LH secretory deficit by approximately one-half. We then measured LHRH-mediated (10-8 M) vs. A23187-mediated (10-4 M) LH release with and without extracellular calcium (0.08-1.5 mM). For cells from both mature and old rats, there was a similar calcium dependency for A23187- and LHRH-mediated LH release, with optimal LH secretion at 1.0-1.5 mM extracellular calcium concentrations. Again, both LHRH- and A23187-stimulated LH release was significantly lower and exposure to A23187 led to a greater increase in LH release from cells of old rats. Taken together with similar findings in other systems, these data suggest that the in vitro LH secretory defect of pituitary cells from old rats results in part from one or more defects in calcium mobilization and that such alterations may be a widespread manifestation of aging.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume253
Issue number3
StatePublished - 1987

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Ionophores
Calcimycin
Luteinizing Hormone
Rats
Defects
Gonadotropin-Releasing Hormone
Calcium
Cells
Information Systems
Wistar Rats
Aging of materials

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Physiology

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Ionophore A23187 partially reverses LH secretory defect of pituitary cells from old rats. / Chuknyiska, R. S.; Blackman, Marc R.; Roth, G. S.

In: American Journal of Physiology - Endocrinology and Metabolism, Vol. 253, No. 3, 1987.

Research output: Contribution to journalArticle

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