RESPONSE OF LUTEINIZING HORMONE FROM COLUMNS OF DISPERSED RAT PITUITARY CELLS TO A HIGHLY POTENT ANALOGUE OF LUTEINIZING HORMONE RELEASING HORMONE

1981 ◽  
Vol 91 (1) ◽  
pp. 33-41 ◽  
Author(s):  
T. YEO ◽  
A. GROSSMAN ◽  
P. BELCHETZ ◽  
G. M. BESSER
Keyword(s):  
Luteinizing Hormone ◽  
Single Pulse ◽  
Pituitary Cells ◽  
Response Curves ◽  
Releasing Hormone ◽  
Rat Pituitary ◽  
Constant Dose ◽  
Rat Pituitary Cells ◽  
Lh Rh ◽  
Lh Releasing Hormone

The response of LH from a perfused column of dispersed rat anterior pituitary cells to LH releasing hormone (LH-RH) and the analogue, d-Ser(But)6-desGly10-Proethylamide9-LH-RH (Hoe 766), was investigated. Dose–response curves showed non-parallelism between LH-RH and the analogue, but it was evident that the analogue was considerably more potent. After a single pulse of LH-RH, LH output returned to basal values in 8 min; this was prolonged to 20 min in the case of the analogue. During this 20 min the cells were refractory to pulses of LH-RH but pulses of the analogue maintained output of LH. During constant-dose perfusion with either synthetic LH-RH or the analogue, output of LH rapidly reached a peak and then gradually fell over several hours to approach baseline values. However, a pulse of 50 mmol potassium chloride/l was still able to release LH at this time. The data are consistent with the view that this analogue of LH-RH is highly potent and is strongly bound by the LH-RH receptor. Furthermore, since it desensitizes the LH-RH receptor, it appears that continued turnover of either LH-RH or the analogue at the receptor is necessary for output of LH to be maintained.

Melatonin inhibits luteinizing hormone releasing hormone (LHRH) induction of LH release from fetal rat pituitary cells

1995 ◽  
Vol 184 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Atsuhiko Hattori ◽  
Damon C. Herbert ◽  
Mary K. Vaughan ◽  
Ken Yaga ◽  
Russel J. Reiter
Keyword(s):  
Luteinizing Hormone ◽  
Pituitary Cells ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Fetal Rat ◽  
Rat Pituitary ◽  
Lh Release ◽  
Rat Pituitary Cells

INHIBIN FROM CULTURES OF RAT SEMINIFEROUS TUBULES

1978 ◽  
Vol 78 (2) ◽  
pp. 217-224 ◽  
Author(s):  
L. W. EDDIE ◽  
H. W. G. BAKER ◽  
A. DULMANIS ◽  
R. E. HIGGINSON ◽  
B. HUDSON
Keyword(s):  
Luteinizing Hormone ◽  
Active Material ◽  
Gel Filtration ◽  
Seminiferous Tubules ◽  
Pituitary Cells ◽  
Basal Secretion ◽  
Luteinizing Hormone Releasing Hormone ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Lh Rh

SUMMARY Medium from cultures of mature rat seminiferous tubules contained a substance which suppressed, in a dose-related manner, the luteinizing hormone releasing hormone (LH-RH)-stimulated secretion of FSH by cultured rat pituitary cells. The secretion of LH was suppressed to a lesser extent and the basal secretion of both LH and FSH was inconsistently affected. Gel filtration on Sephadex G-100 did not fractionate the activity. The active material did not inhibit the secretion of TSH or destroy LH-RH and the activity was not due to testosterone or oestradiol in the medium. Control media from liver cultures were inactive. It is concluded that inhibin is present in media from cultures of rat seminiferous tubules.

STIMULATION OF RELEASE OF LUTEINIZING HORMONE FROM CULTURED PITUITARY CELLS BY 2- AND 4-HYDROXYLATED OESTROGENS

1981 ◽  
Vol 90 (3) ◽  
pp. 433-436 ◽  
Author(s):  
S. FRANKS ◽  
G. R. MERRIAM ◽  
CYNTHIA G. GOODYER ◽  
F. NAFTOLIN
Keyword(s):  
Luteinizing Hormone ◽  
Anterior Pituitary ◽  
Monolayer Culture ◽  
Pituitary Cells ◽  
Releasing Hormone ◽  
Oestradiol Treatment ◽  
Lh Rh ◽  
Lh Releasing Hormone ◽  
Stimulation Of

We have examined the effects of the catechol oestrogens 2-hydroxyoestradiol (2-OHE2), 4-hydroxyoestradiol (4-OHE2) and 2-hydroxyoestrone (2-OHE1) and their corresponding primary oestrogens on secretion of LH and FSH by enzymatically dispersed rat anterior pituitary cells in monolayer culture. Basal LH levels in the medium were significantly higher than in control wells when cells were exposed to 10−8m-oestradiol-17β for 40 h: oestrone and all three catechol oestrogens (in the same doses) also stimulated basal LH concentrations to levels quantitatively similar to those seen after oestradiol treatment. The same effects were observed when steroids were given at 10−9 mol/l. Oestradiol, 2-OHE2, and 4-OHE2 but not 2-OHE1 increased pituitary responsiveness to LH releasing hormone (LH-RH) (given in a range of doses from 10−11 to 10−6 mol/l). The responses of cells treated with 2-OHE2 and 4-OHE2 were similar, though less than the response seen after treatment with oestradiol. This contrasts with the very different oestrogenic effects of 2- and 4-OHE2 previously observed in vivo. Neither oestradiol nor the catechol oestrogens had any effect on basal or LH-RH-stimulated FSH release.

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