Dihydrotestosterone and Estradiol Regulating the Activity of 3α-Hydroxysteroid Dehydrogenase in the Pituitary Gland of the Rat: Action of Antiestrogens

1981 ◽  
pp. 347-348
Author(s):  
R. Ghraf ◽  
K. Schneider ◽  
J. Kirchhoff ◽  
C. Hiemke
Keyword(s):  
Pituitary Gland ◽  
Hydroxysteroid Dehydrogenase

METABOLISM OF [14C]TESTOSTERONE BY HUMAN FOETAL AND ADULT BRAIN TISSUE

1977 ◽  
Vol 74 (3) ◽  
pp. 425-429 ◽  
Author(s):  
J. S. JENKINS ◽  
C. J. HALL
Keyword(s):  
Pituitary Gland ◽  
Brain Tissue ◽  
Temporal Lobe ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Adult Brain ◽  
Similar Activity ◽  
Foetal Brain ◽  
Brain Tissues

SUMMARY The metabolism of [14C]testosterone in vitro by various areas of the human foetal brain has been studied and compared with that of adult brain. The predominant metabolites were 5α-dihydrotestosterone and 5α-androstane-3α,17β-diol, and also androstenedione, and all areas of the foetal brain showed similar activity. In the foetal pituitary gland, the activity of 5α-reductase was less prominent than that of 17β-hydroxysteroid-dehydrogenase. Small quantities of oestradiol-17β were produced from testosterone by the hypothalamus, temporal lobe and amygdala only, and no aromatization could be detected in the pituitary gland. 5α-Reductase activity was much lower in adult brain tissues and no oestradiol was identified in adult temporal lobe tissue.

EFFECT OF ERGOCORNINE ON OVARIAN SYNTHESIS OF PROGESTERONE AND 20α-HYDROXY-PREGN-4-EN-3-ONE IN THE PSEUDOPREGNANT RAT

1967 ◽  
Vol 56 (1) ◽  
pp. 27-34 ◽  
Author(s):  
H. R. Lindner ◽  
M. C. Shelesnyak
Keyword(s):  
Pituitary Gland ◽  
Subcutaneous Injection ◽  
Control Level ◽  
Hydroxysteroid Dehydrogenase ◽  
Prolactin Secretion ◽  
Direct Inhibition ◽  
Excitatory Effect ◽  
Sharp Rise ◽  
And Control ◽  
Total P

ABSTRACT The ovarian content of progesterone (P) and 20α-hydroxy-pregn-4-en-3-one (20αOHP) was measured in rats given a subcutaneous injection of 1 mg ergocornine methanesulphate (ECO) on day L4 of pseudopregnancy and in untreated pseudopregnant controls. The progesterone content in the ovaries of the treated rats declined, after a latency of 12 h, to 44% of the control level at 24 h, and to 30% at 30 to 72 h after the ECO injection. This fall in progesterone level coincided with a sharp rise in 20αOHP content of the ovaries and consequent inversion of the P/20αOHP ratio, from 1.9–3.8 in the controls to 0.24–0.45 in the ECO-treated rats. The total P + 20αOHP content of the ovaries remained similar in treated and control rats, except for a significant fall 48 h after ECO injection. The changes in ovarian steroid content after ECO administration mimic those observed during spontaneous prooestrus and oestrus and account for the interruption of the progestational state brought about by the drug. The results negate the postulate that ECO exerts its pregnancy-interrupting action in the rat by direct inhibition of ovarian 3β-hydroxysteroid dehydrogenase and are consistent with the view that this action of the drug is mediated by suppression of prolactin secretion by the pituitary gland; such a suppression may be secondary to an excitatory effect on the hypothalamus.

Properties of 3α-hydroxysteroid dehydrogenase of the male rat pituitary gland

1975 ◽  
Vol 6 (7) ◽  
pp. 1165-1169 ◽  
Author(s):  
Nguyen Cong Thien ◽  
Suzanne Samperez ◽  
Pierre Jouan
Keyword(s):  
Pituitary Gland ◽  
Hydroxysteroid Dehydrogenase ◽  
Male Rat ◽  
Rat Pituitary

Improved immunolabelling of ultrathin cryosections using antibody conjugated with 1nm gold particles

1990 ◽  
Vol 48 (3) ◽  
pp. 928-929
Author(s):  
Morten H. Nielsen ◽  
Lone Bastholm
Keyword(s):  
Pituitary Gland ◽  
Liquid Nitrogen ◽  
Electron Density ◽  
Small Diameter ◽  
Cytochemical Staining ◽  
Gold Particles ◽  
Labelling Density ◽  
Ultrathin Cryosections ◽  
Mouse Pituitary ◽  
Electron Microscopical

During the last 5 years the diameter of the gold probes used for immuno-cytochemical staining at the electron microscopical (EM) level has been decreased. The advantage of small diameter gold probes is an overall increased labelling density. The disadvantage is a lower detectability due to the low electron density of smaller gold particles consequently an inconvenient high primary magnification needed for EM examination. Since 1 nm gold particles are barely visible by conventional EM examination the need for enlargement by silverenhancement of the gold particles has increased.In the present study of ultrathin cryosectioned material the results of immunostaining using 5 nm gold conjugated antibody and 1 nm gold conjugated antibodies are compared after silverenhancement of the 1 nm gold particles.Slices of freshly isolated mouse pituitary gland were immersion fixed for 20 min in 2 % glutaraldehyde /2 % paraformaldehyde. Blocks cryoprotected with 2.3 M sucrose were frozen in liquid nitrogen and ultra-cryosectioned on a RMC cryoultra-microtome.

Immunohistochemical studies on 3β-hydroxysteroid dehydrogenase in the adult human adrenal

1998 ◽  
Vol 5 (1) ◽  
pp. 94A-94A
Author(s):  
R MIXON ◽  
R BRISSIE ◽  
W GRIZZLE ◽  
J THOMAS ◽  
O FAYEPELERSEN ◽  
...  
Keyword(s):  
Hydroxysteroid Dehydrogenase ◽  
Adult Human ◽  
Immunohistochemical Studies
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