Cell cycle distributions, growth characteristics, and variation in prolactin and growth hormone production in cultured rat pituitary cells

1977 ◽  
Vol 23 (1) ◽  
Author(s):  
O. P. F. Clausen ◽  
K. M. Gautvik ◽  
T. Lindmo
Keyword(s):  
Cell Cycle ◽  
Growth Hormone ◽  
Growth Characteristics ◽  
Pituitary Cells ◽  
Hormone Production ◽  
Rat Pituitary ◽  
Rat Pituitary Cells

scholarly journals PRODUCTION OF BOTH PROLACTIN AND GROWTH HORMONE BY CLONAL STRAINS OF RAT PITUITARY TUMOR CELLS

1970 ◽  
Vol 47 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Armen H. Tashjian ◽  
Frank C. Bancroft ◽  
Lawrence Levine
Keyword(s):  
Growth Hormone ◽  
Mammalian Cells ◽  
Cell Protein ◽  
Pituitary Cells ◽  
Hormone Production ◽  
Rat Pituitary ◽  
Organ Specific ◽  
Cell Strains ◽  
Rat Pituitary Tumor Cells ◽  
Rat Pituitary Cells

Several established clonal strains of rat pituitary cells which produce growth hormone in culture have been shown to secrete a second protein hormone, prolactin. Prolactin was measured immunologically in culture medium and within cells by complement fixation. Rates of prolactin production varied from 6.6 to 12 µg/mg cell protein per 24 hr in four different cell strains. In these cultures ratios of production of prolactin to growth hormone varied from 1.0 to 4.1. A fifth clonal strain produced growth hormone but no detectable prolactin. Intracellular prolactin was equivalent to the amount secreted into medium in a period of about 1–2 hr. Both cycloheximide and puromycin suppressed prolactin production by at least 94%. Hydrocortisone (3 x 10-6 M), which stimulated the production of growth hormone 4- to 8-fold in most of the cell strains, reduced the rate of prolactin production to less than 25% of that in control cultures. Conversely, addition of simple acid extracts of several tissues, including hypothalamus, to the medium of all strains increased the rate of production of prolactin six to nine times and decreased growth hormone production by about 50%. We conclude that multifunctional rat pituitary cells in culture show unusual promise for further studies of the control of expression of organ-specific activities in mammalian cells.

Glutathione-Dependent Thyroxine 5′-Monodeiodination Modulates Growth Hormone Production by Cultured Nonthyrotropic Rat Pituitary Cells*

Endocrinology ◽  
1981 ◽  
Vol 108 (3) ◽  
pp. 970-976 ◽  
Author(s):  
SHLOMO MELMED ◽  
MICHAEL NELSON ◽  
NEIL KAPLOWITZ ◽  
TADATAKA YAMADA ◽  
JEROME M. HERSHMAN
Keyword(s):  
Growth Hormone ◽  
Pituitary Cells ◽  
Hormone Production ◽  
Rat Pituitary ◽  
Rat Pituitary Cells

scholarly journals CONTROL OF GROWTH HORMONE PRODUCTION BY A CLONAL STRAIN OF RAT PITUITARY CELLS

1969 ◽  
Vol 43 (3) ◽  
pp. 432-441 ◽  
Author(s):  
Frank C. Bancroft ◽  
Lawrence Levine ◽  
Armen H. Tashjian
Keyword(s):  
Growth Hormone ◽  
Doubling Time ◽  
Population Doubling ◽  
Cell Protein ◽  
Pituitary Cells ◽  
Hormone Production ◽  
Clonal Strain ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
And Control

Addition of hydrocortisone to the medium of a clonal strain of rat pituitary cells (GH3) stimulated the rate of production of growth hormone. The stimulation had a lag period of about 24 hr, reached a maximum at 70–100 hr, and was observed at a hydrocortisone concentration as low as 5 x 10-8 M. Cells maximally stimulated with 3 x 10-6 M hydrocortisone produced 50–160 µg growth hormone/mg cell protein/24 hr. These rates were four to eight times those observed in control cells. At maximum stimulation, intracellular levels of growth hormone in both stimulated and control cells were equal to the amount secreted into the medium in about 15 min. Removal of hydrocortisone from the medium of GH3 cells caused a return of the rate of growth hormone production to that in control cells. Addition of hydrocortisone to the medium of cells growing exponentially with a population-doubling time of 60 hr caused both an increase in the doubling time to 90 hr and a stimulation of growth hormone production. Cycloheximide (3.6 x 10-5 M) and puromycin (3.7 x 10-4 M) suppressed incorporation of labeled amino acids into protein by 93 and 98%, respectively, and suppressed growth hormone production by stimulated and control cells by at least 94%.

EFFECTS OF SEX STEROIDS ON GROWTH HORMONE PRODUCTION IN CULTURED RAT PITUITARY CELLS

1978 ◽  
Vol 87 (1) ◽  
pp. 40-54 ◽  
Author(s):  
E. Haug ◽  
K. M. Gautvik
Keyword(s):  
Growth Hormone ◽  
Sex Steroids ◽  
Pituitary Tumour ◽  
Maximum Effect ◽  
Pituitary Cells ◽  
Hormone Production ◽  
Thyrotrophin Releasing Hormone ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Dose Dependent

ABSTRACT Monolayer cultures of rat pituitary tumour cells (GH3) were used to study the effects of different sex steroids on growth hormone (GH) production expressed as the amount of extracellular hormone which accumulated during 24 h. The hormone was measured with a sensitive and specific radioimmunoassay. Oestradiol-17β (10−12 mol/l—10−6 mol/l) caused a dose-dependent decrease in GH production with the maximum effect (30 % of controls) at 10−10 mol/l. After the cessation of treatment with oestradiol-17β (10−8 mol/l for 7 days), control levels of GH were obtained within 11 days, after a transient augmentation of production. Progesterone (10−11–10−6 mol/l) caused a dose-dependent stimulation of GH production, and the maximum effect (160 % of controls) was observed at 10−6 mol/l. Testosterone (10−6 mol/l) decreased the production of GH to 70 % of control values, whereas 5α-dihydrotestosterone (DHT) had no effect. Cell growth was not affected by any of the sex steroids. Corticosterone (10−6 mol/l) increased GH production to about 400 % of control values, and this effect was inhibited by oestradiol-17β (10−6 mol/l). The hypothalamic peptides, thyrotrophin releasing hormone (TRH) and somatostatin, that both depressed GH production did not significantly inhibit the stimulatory effect of corticosterone. When used in combination, the effects of oestradiol-17β (10−6 mol/l) and TRH (3 × 10−7 mol/l) were additive which was not the case for the combination oestradiol-17β (10−6 mol/l) and testosterone (10−6 mol/l). These results suggest different mechanisms of action of peptide and steroid hormones on GH production in the GH3 cells. If the properties of the GH3 cells reflect those of normal somatotrophs the sex steroids may alter GH production at the pituitary level, an influence that may be further modulated by corticoids, TRH and somatostatin.

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