Decreased in vitro secretion of LH, FSH, and free alpha-subunits by pituitary cells from old male rats.

Marc R. Blackman, A. Mukherjee, P. D. Tsitouras, S. M. Harman

Research output: Contribution to journalArticle

Abstract

Various in vivo and in vitro pituitary-Leydig cell functions were examined in mature (5-8 mo) vs. old (22-25 mo) male Wistar rats. Old rats exhibited decreased serum concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) (P less than 0.0025) but similar levels of prolactin (P less than 0.01) both before and 4 wk after castration. The in vitro release of LH, FSH, and free alpha-subunits was measured in primary cultures of dispersed anterior pituitary cells from both intact and castrated rats. During 48 h of incubation, basal secretion rates of the glycoproteins were decreased (P less than 0.001) from cells of both intact and castrated old rats. After stimulation with LH-releasing hormone (LRH) in single (10(-8) M) or multiple (10(-10) - 10(-7) M) doses, the total amounts of the glycoproteins secreted were also less from cells of both intact and castrated old rats. However, repeated measures analysis of variance revealed age-related hyporesponsivity to LRH stimulation only for LH secretion by cells from intact rats. The basal molar ratios of alpha/(LH + FSH) secreted by cells from intact but not castrated old rats were lower than those from cells of the corresponding mature rats. Moreover, after LRH stimulation (10(-10) - 10(-7) M), molar secretory ratios of alpha/(LH + FSH) decreased from cells of intact mature rats but increased from cells of intact old rats. These in vitro data suggest that the reduced serum LH and FSH levels in intact and castrated old male rats result in part from decreased secretion of these glycoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Original languageEnglish (US)
JournalThe American journal of physiology
Volume249
Issue number2 Pt 1
StatePublished - Aug 1985

Fingerprint

Alpha Subunit Glycoprotein Hormones
Luteinizing Hormone
Follicle Stimulating Hormone
Gonadotropin-Releasing Hormone
Glycoproteins
In Vitro Techniques
Leydig Cells
Castration
Serum
Prolactin
Testosterone
Wistar Rats
Analysis of Variance

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Decreased in vitro secretion of LH, FSH, and free alpha-subunits by pituitary cells from old male rats. / Blackman, Marc R.; Mukherjee, A.; Tsitouras, P. D.; Harman, S. M.

In: The American journal of physiology, Vol. 249, No. 2 Pt 1, 08.1985.

Research output: Contribution to journalArticle

@article{6e93b5bd39a140f3b015c2d2c1df574f,
title = "Decreased in vitro secretion of LH, FSH, and free alpha-subunits by pituitary cells from old male rats.",
abstract = "Various in vivo and in vitro pituitary-Leydig cell functions were examined in mature (5-8 mo) vs. old (22-25 mo) male Wistar rats. Old rats exhibited decreased serum concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) (P less than 0.0025) but similar levels of prolactin (P less than 0.01) both before and 4 wk after castration. The in vitro release of LH, FSH, and free alpha-subunits was measured in primary cultures of dispersed anterior pituitary cells from both intact and castrated rats. During 48 h of incubation, basal secretion rates of the glycoproteins were decreased (P less than 0.001) from cells of both intact and castrated old rats. After stimulation with LH-releasing hormone (LRH) in single (10(-8) M) or multiple (10(-10) - 10(-7) M) doses, the total amounts of the glycoproteins secreted were also less from cells of both intact and castrated old rats. However, repeated measures analysis of variance revealed age-related hyporesponsivity to LRH stimulation only for LH secretion by cells from intact rats. The basal molar ratios of alpha/(LH + FSH) secreted by cells from intact but not castrated old rats were lower than those from cells of the corresponding mature rats. Moreover, after LRH stimulation (10(-10) - 10(-7) M), molar secretory ratios of alpha/(LH + FSH) decreased from cells of intact mature rats but increased from cells of intact old rats. These in vitro data suggest that the reduced serum LH and FSH levels in intact and castrated old male rats result in part from decreased secretion of these glycoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)",
author = "Blackman, {Marc R.} and A. Mukherjee and Tsitouras, {P. D.} and Harman, {S. M.}",
year = "1985",
month = "8",
language = "English (US)",
volume = "249",
journal = "American Journal of Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "2 Pt 1",

}

TY - JOUR

T1 - Decreased in vitro secretion of LH, FSH, and free alpha-subunits by pituitary cells from old male rats.

AU - Blackman, Marc R.

AU - Mukherjee, A.

AU - Tsitouras, P. D.

AU - Harman, S. M.

PY - 1985/8

Y1 - 1985/8

N2 - Various in vivo and in vitro pituitary-Leydig cell functions were examined in mature (5-8 mo) vs. old (22-25 mo) male Wistar rats. Old rats exhibited decreased serum concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) (P less than 0.0025) but similar levels of prolactin (P less than 0.01) both before and 4 wk after castration. The in vitro release of LH, FSH, and free alpha-subunits was measured in primary cultures of dispersed anterior pituitary cells from both intact and castrated rats. During 48 h of incubation, basal secretion rates of the glycoproteins were decreased (P less than 0.001) from cells of both intact and castrated old rats. After stimulation with LH-releasing hormone (LRH) in single (10(-8) M) or multiple (10(-10) - 10(-7) M) doses, the total amounts of the glycoproteins secreted were also less from cells of both intact and castrated old rats. However, repeated measures analysis of variance revealed age-related hyporesponsivity to LRH stimulation only for LH secretion by cells from intact rats. The basal molar ratios of alpha/(LH + FSH) secreted by cells from intact but not castrated old rats were lower than those from cells of the corresponding mature rats. Moreover, after LRH stimulation (10(-10) - 10(-7) M), molar secretory ratios of alpha/(LH + FSH) decreased from cells of intact mature rats but increased from cells of intact old rats. These in vitro data suggest that the reduced serum LH and FSH levels in intact and castrated old male rats result in part from decreased secretion of these glycoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)

AB - Various in vivo and in vitro pituitary-Leydig cell functions were examined in mature (5-8 mo) vs. old (22-25 mo) male Wistar rats. Old rats exhibited decreased serum concentrations of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) (P less than 0.0025) but similar levels of prolactin (P less than 0.01) both before and 4 wk after castration. The in vitro release of LH, FSH, and free alpha-subunits was measured in primary cultures of dispersed anterior pituitary cells from both intact and castrated rats. During 48 h of incubation, basal secretion rates of the glycoproteins were decreased (P less than 0.001) from cells of both intact and castrated old rats. After stimulation with LH-releasing hormone (LRH) in single (10(-8) M) or multiple (10(-10) - 10(-7) M) doses, the total amounts of the glycoproteins secreted were also less from cells of both intact and castrated old rats. However, repeated measures analysis of variance revealed age-related hyporesponsivity to LRH stimulation only for LH secretion by cells from intact rats. The basal molar ratios of alpha/(LH + FSH) secreted by cells from intact but not castrated old rats were lower than those from cells of the corresponding mature rats. Moreover, after LRH stimulation (10(-10) - 10(-7) M), molar secretory ratios of alpha/(LH + FSH) decreased from cells of intact mature rats but increased from cells of intact old rats. These in vitro data suggest that the reduced serum LH and FSH levels in intact and castrated old male rats result in part from decreased secretion of these glycoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)

UR - http://www.scopus.com/inward/record.url?scp=0022103932&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0022103932&partnerID=8YFLogxK

M3 - Article

VL - 249

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6135

IS - 2 Pt 1

ER -