Die Cholesterin-7α-Hydroxylase-Aktivität der Rattenleber nach Hypophysektomie und nach Substitution mit Hypophysenhormonen

Summary In order to elucidate the role of the hypophysis in the regulation of cholesterol 7-hydroxylase activity, male and female rats hypophysectomized on day 50 of life were treated with different hypophyseal hormones and tested on day 85 of life. Only a crude extract from human hypophysis and ovine prolactin was able to enhance the enzyme activity, thereby restoring the level of intact controls.

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Diese Arbeit wurde im Rahmen des Sonderforschungsbereiches Endokrinologie (SFB 87) von der Deutschen Forschungsgemeinschaft gefördert.     

Pituitary control of androgen synthesis in the rat embryo]

Removal of the hypophysis by decapitation of the 19--or 20 days--old Rat embryo is followed by a significant decrease in the ability of the embryonic testis to synthesize testosterone and androstenedione from acetate in vitro. It is concluded that pituitary-testis relationships first appear at 19 days of intrauterine life.     

Effects of ovariectomy on the oxidative metabolism of the central nervous system and adrenal glands in female hamster (Mesocricetus auratus)

We have studied the influence of ovariectomy on the oxidative activity of hypophysis, hypothalamus, posterior cortex, septal area, amygdala and adrenal glands, in female hamsters, because their neuroendocrine behavior seems to differ from that of rats. Our results show a decreasing the O2 uptake in the hypothalamus and adrenal glands and an increase in the rest of the structures.     

Effects of ovariectomy on the oxidative metabolism of the central nervous system and adrenal glands in female hamster (Mesocricetus auratus)

Summary We have studied the influence of ovariectomy on the oxidative activity of hypophysis, hypothalamus, posterior cortex, septal area, amygdala and adrenal glands, in female hamsters, because their neuroendocrine behavior seems to differ from that of rats. Our results show a decreasing the O₂ uptake in the hypothalamus and adrenal glands and an increase in the rest of the structures.     

Changes in the level of ACTH in the fetal hypophysis. A study in the rat toward the end of gestation]

The isolated adrenal cell method for bioassay of ACTH was employed in order to determine the ACTH content of the hypophysis of the rat foetus, in late pregnancy. The ACTH concentration decreases between 17 days 8 h and 17 days 15 h, then it increases regularly until the term. This evolution is correlated with the change in the fluorescence intensity of the corticotrophs and with the modification of the adrenocortical activity.     

Changes in the distribution of gamma-glutamyl transferase in the organs of the mouse as a function of development]

In the Mouse, gamma-glutamyl transferase distribution changes with development in the kidney and the liver; on the contrary, its activity remains almost equal and low in other organs. In the liver, a low activity is observed in the fetus and the new-born up to the 3rd day of life; then it is no more measurable. In the kidney, the low enzyme activity of the fetus is multiplied by 10 in the 10 first days of life and by 50 in the 6 first weeks.     

The adenohypophysial hormone content of the rat pars tuberalis.

The pars tuberalis of the hypophysis was shown to contain LH, which increases after castration, TSH and a very low amount of PRL. FSH was found after castration.     

A gonadotropin releasing hormone analog induces spermiation in intact and hypophysectomized frogs, Rana esculenta

The sperm-releasing activity of a gonadotropin releasing hormone (GnRH) agonist, Buserelin (GnRH) and hypophysis homogenate (PD) preparations was studied in intact and hypophysectomized (PDX) frogs, Rana esculenta. In addition, human chorion gonadotropin (hCG) was tested in PDX animals, and GnRH antagonist (GnRHA) treatments were carried out in intact and PDX animals, in combination with the hormonal injections. GnRH or PD treatments were able to elicit spermiation in intact and PDX animals. While GnRH, injected 24 h later, was again effective in inducing spermiation in intact animals, this was not the case in PDX frogs. GnRHA counteracted GnRH effects in intact frogs. Moreover, in PDX animals GnRHA injections counteracted the sperm-releasing activity induced by hCG or GnRH, but failed to inhibit sperm-releasing activity induced by PD homogenate.     

Quantitative Bestimmung von RNS-Fraktionen im Gehirn frisch geschlüpfter Bienen (Apis mellifica)

Summary In the brain of the honeybee (Apis mellifica), it was found that the rRNA content decreases rapidly during the first 2 days of adult life. An increase is observed from days 3 to 5, followed by another decrease to a level inferior to that of day 2 to 3. Except for a rise on the 5th day, 4s RNA remains constant. An unidentified RNA fraction of low molecular weight (D) sharply decreases on day 5. The possibility is discussed that these results reflect changes in RNA metabolism that can be related to the sequences of activity observed in the bees during the first 9 days after hatching.     

Binding bovine immunoglobulins to anterior lobe cells of the hypophysis.

Cells of the anterior lobe of the bovine hypophysis, show an affinity for immunoglobulins IgG, IgA and IgM. The phenomenon either provides a message to stimulate cellular secretion or to excite mechanisms associated with the synthesis and release of Ig's or their determinants.     

Fluorescence histochemical demonstration of the uptake of dopamine-derived dihydroisoquinoline in the hypothalamic neurons

Summary The uptake and the accumulation of dopamine-derived fluorescent dihydroisoquinoline were demonstrated with direct fluorescence histochemistry in the hypothalamic dopaminergic neurons, in the nerves of the neurointermediate lobe, and in some endocrine cells of the hypophysis of the rat.     

Binding bovine immunoglobulins to anterior lobe cells of the hypophysis

Summary Cells of the anterior lobe of the bovine hypophysis, show an affinity for immunoglobulins IgG, IgA and IgM. The phenomenon either provides a message to stimulate cellular secretion or to excite mechanisms associated with the synthesis and release of Ig's or their determinants.This study was supported by a grant from the National Research council of Canada.     

Fetal hypophysis as the main source of serum TSH in fetal rat

Decapitation performed at days 17-18 leads to a drastic drop (82%) in blood TSH of 19 and 21-day-old rat fetuses below the mother's level. 125I-TSH injected at 21 days into the mother's bloodstream is not found in fetal blood. The fetal hypophysis is the main source of fetal plasmatic TSH.     

The adenohypophysial hormone content of the rat pars tuberalis

Summary The pars tuberalis of the hypophysis was shown to contain LH, which increases after castration, TSH and a very low amount of PRL. FSH was found after castration.This investigation was supported by the Fundación Instituto de Neurobiología and CONICET. The authors want to thank Dr A.F. Parlow for supplying the NIAMDD radioimmunoassay kits.     

Description of the folliculo-stellate cells in the anterior hypophysis of the monkey Macacus irus]

Folliculo-stellar cells are present in the anterior lobe of hypophysis of the monkey Macacus irus. These cells limit strait cavities in which one can observe microvillosites at the apical pole of the cells. The folliculo-stellar cells possess long and thin fibers which insert themselves between different types of granular cells and sometimes extend to the peri-capillar regions. Numerous organelles are present in these folliculo-stellar cells, especially microfilaments.     

Fetal hypophysis as the main source of serum TSH in fetal rat

Summary Decapitation performed at days 17–18 leads to a drastic drop (82%) in blood TSH of 19 and 21-day-old rat fetuses below the mother's level.¹²⁵I-TSH injected at 21 days into the mother's bloodstream is not found in fetal blood. The fetal hypophysis is the main source of fetal plasmatic TSH.     

Cyto-immunochemical detection of gamma endorphin in swine adenohypophysis]

An immunserum was prepared from gamma endorphin and its specifity was checked by the indirect method. It was tested on hypophysis which were taken from Pigs since birth till 3 months old. The anterior lobe as well as the intermediate lobe have reacted. The same cells were positive in the anterior lobe and recognized the anti-ACTH, anti-beta MSH and anti-beta LPH immunserums. However, the reaction was more labile than with these last immunserums and it was varying with the delay of fixation after the death and the penetration in the gland by the fixator.     

Die postnatale Entwicklung der Bursttätigkeit im Bulbus olfactorius des Kaninchens

Summary An investigation of the olfactory burst activity was undertaken in rabbits during 1–8 days of life. The bursts are already present at the first postnatal day (frequency 18 c/sec, amplitude 23µV). The values of the adult animal are reached at 8 days.     

Changes in brush-border enzyme activities of intestinal epithelial cells isolated from the villus-crypt axis during the early phase of alloxan diabetes in rats

The sucrase activity in enterocytes isolated from the villus crypt axis was found to increase in all regions of the villus from day 2 after induction of diabetes, and the increase continued until day 4. In contrast, alkaline phosphatase activity increased mainly in the apical one-third of the villus-crypt column, and the increase occurred abruptly on day 4 with increase in food intake.     

Changes in brush-border enzyme activities of intestinal epithelial cells isolated from the villus-crypt axis during the early phase of alloxan diabetes in rats

Summary The sucrase activity in enterocytes isolated from the villus crypt axis was found to increase in all regions of the villus from day 2 after induction of diabetes, and the increase continued until day 4. In contrast, alkaline phosphatase activity increased mainly in the apical one-third of the villus-crypt column, and the increase occurred abruptly on day 4 with increase in food intake.