CYTOLOGICAL AND CYTOCHEMICAL COMPARATIVE STUDY ON THE EFFECT OF CYPROTERONE (ANTI-ANDROGEN) AND GONADECTOMY ON THE GONADOTROPHIC CELLS OF THE HYPOPHYSIS IN MALE RATS

1969 ◽  
Vol 61 (2) ◽  
pp. 293-301 ◽  
Author(s):  
Kazimierz Mietkiewski ◽  
Ludwik Malendowicz ◽  
Andrzej Lukaszyk
Keyword(s):  
Acid Phosphatase ◽  
Comparative Study ◽  
Adaptive Systems ◽  
Competitive Inhibitor ◽  
Anterior Lobe ◽  
Male Rats ◽  
Mucoid Cells ◽  
Gonadotrophic Cells

ABSTRACT Cyproterone, a competitive inhibitor of testosterone, injected into male rats in daily doses of 10 mg, induces hypertrophy and hyperplasia of the mucoid cells of the hypophysis, followed by the appearance of castration cells. The largest number of these cells is observed on the 12th test-day. These changes are accompanied by degranulation of mucoid cells and an increase in the reactions for acid phosphatase and non-specific esterases. As the injection of cyproterone is continued, the number of castration cells in the anterior lobe of the hypophysis decreases and the cytoenzymic reactions observed show a fall in intensity. Gonadectomy, on the contrary, brings about lasting characteristic changes in the anterior lobe of the hypophysis, which mainly consist in the occurrence of castration cells accompanied by an increase in the intensity of reactions for acid phosphatase and non-specific esterases. The above data suggest that in the course of administration of cyproterone, suitable adaptive systems develop in the organism which inhibit the action of this anti-androgen.

Fine Structural Changes in the Adenohypophyses of Rats Following Destruction of the Pituitary Stalk

1977 ◽  
Vol 35 ◽  
pp. 496-497
Author(s):  
K. Kovacs ◽  
E. Horvath ◽  
J. M. Bilbao ◽  
F. A. Laszlo ◽  
I. Domokos
Keyword(s):  
Structural Changes ◽  
Tissue Injury ◽  
Anterior Lobe ◽  
Uranyl Acetate ◽  
Male Rats ◽  
Pituitary Stalk ◽  
Sequence Of Events ◽  
Pituitary Glands ◽  
Electrolytic Lesions ◽  
Ultrathin Sections

Electrolytic lesions of the pituitary stalk in rats interrupt adenohypophysial blood flow and result in massive infarction of the anterior lobe. In order to obtain a deeper insight into the morphogenesis of tissue injury and to reveal the sequence of events, a fine structural investigation was undertaken on adenohypophyses of rats at various intervals following destruction of the pituitary stalk.The pituitary stalk was destroyed electrolytically, with a Horsley-Clarke apparatus on 27 male rats of the R-Amsterdam strain, weighing 180-200 g. Thirty minutes, 1,2,4,6 and 24 hours after surgery the animals were perfused with a glutaraldehyde-formalin solution. The skulls were then opened and the pituitary glands removed. The anterior lobes were fixed in glutaraldehyde-formalin solution, postfixed in osmium tetroxide and embedded in Durcupan. Ultrathin sections were stained with uranyl acetate and lead citrate and investigated with a Philips 300 electron microscope.

THE DEVELOPMENT OF A FEEDBACK MECHANISM BETWEEN THE OVARY AND THE DIENCEPHALIC-HYPOPHYSIAL SYSTEM IN THE RAT

1963 ◽  
Vol 26 (2) ◽  
pp. 287-NP ◽  
Author(s):  
J. PRESL ◽  
J. HORSKÝ ◽  
M. HENZL ◽  
J. JIRÁSEK
Keyword(s):  
Anterior Pituitary ◽  
Anterior Lobe ◽  
Feedback Mechanism ◽  
Histological Structure ◽  
Histological Investigation ◽  
Basic Information ◽  
Ovarian Weight ◽  
The Difference ◽  
Golgi Zone ◽  
Mucoid Cells

SUMMARY With the object of obtaining basic information concerning the establishment of the feedback mechanism between the ovaries and the diencephalic-hypophysial system (DHS), changes in the gonadotrophic activity and histological structure of the anterior pituitary lobe were determined in groups of rats 21 days following ovariectomy on the day of birth or at 5, 10, 15, 20, 30 and 50 days. It was shown that the gonadotrophic activity of the hypophysis of spayed females and non-spayed controls differed using the criterion of uterine weight of the recipient, following ovariectomy at birth. After spaying at the age of 5 days the difference was also statistically significant using the criterion of ovarian weight. Histological investigation showed that in animals ovariectomized at days 1 and 5 there was an increase in PAS-positive mucoid cells in the adenohypophysis with a distinct PAS-positive Golgi zone in the pale centre of the cytoplasm. The results of these experiments show that a feedback mechanism between the ovaries and the DHS becomes established at an age between (21–x) and (26–x) days, where x is the period necessary for the development of demonstrable post-castration changes in the anterior lobe. In view of the reported initiation of ovarian oestrogen production, the hypothesis is discussed that the feedback mechanism begins to function during very early post-natal life.

scholarly journals Age features of metabolic syndrome effects on fetal embryonic development of the male rat offsprings

2016 ◽  
Vol 21 (2) ◽  
pp. 71-75
Author(s):  
O. Tkachenko ◽  
V. Kovalenko
Keyword(s):  
Metabolic Syndrome ◽  
Embryonic Development ◽  
Comparative Study ◽  
Fetal Death ◽  
Total Mortality ◽  
Male Rats ◽  
Male Rat ◽  
Adult Rats ◽  
Juvenile Age ◽  
Age Features

Comparative study of embryo-fetal death in females fertilized by males with metabolic syndrome, induced in adult or juvenile age has shown that the offspring of adult rats did not have significant abnormalities in embrio- and fetogenesis. At the same time it has been revealed 4% postimplantation death of offspring in male rats with metabolic syndrome induced in the juvenile age. The pre-implantation loss in this group was 6 folds higher than in control. Accordingly, the total mortality of the offspring rose 2.4 times in comparison with control.

scholarly journals Chick osteoblasts contain fluoride-sensitive acid phosphatase activity.

1988 ◽  
Vol 36 (9) ◽  
pp. 1175-1180 ◽  
Author(s):  
M W Lundy ◽  
K H Lau ◽  
H C Blair ◽  
D J Baylink
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Bone Matrix ◽  
Competitive Inhibitor ◽  
Cellular Origin ◽  
Embryonic Chicken ◽  
Low Concentrations

We used histological and biochemical methods to determine the cellular origin of bone matrix fluoride-sensitive acid phosphatase in chicken bone. Embryonic chicken calvariae were embedded in plastic and sections stained for acid phosphatase at various concentrations of substrate and fluoride. Acid phosphatase activity was observed in osteoblasts and osteoclasts but not in fibroblasts. Striking inhibition of osteoblastic acid phosphatase occurred at 100 microM fluoride, a concentration that had no apparent effect on osteoclastic acid phosphatase. Inhibition of osteoblastic and osteoclastic acid phosphatase by fluoride was also examined using extracts of embryonic chicken calvarial cells, mouse osteoblasts (MC3T3-El cell line), and purified chick osteoclasts, respectively. Fluoride is a partial competitive inhibitor of both chicken and mouse osteoblastic acid phosphatases, with apparent inhibition constants of 10-100 microM. These concentrations of fluoride correspond to those that increase bone formation in vitro and in vivo. In contrast, the apparent inhibition constant for fluoride of osteoclastic acid phosphatase was much higher (i.e., 0.5 mM). In summary, this study demonstrates that chicken osteoblasts contain an acid phosphatase that is sensitive to inhibition by low concentrations (i.e., microM) of fluoride.

BIOSYNTHESIS OF GONADOTROPHINS BY RAT PITUITARIES IN VITRO

1975 ◽  
Vol 66 (3) ◽  
pp. 369-374 ◽  
Author(s):  
MRIDULA CHOWDHURY ◽  
EMIL STEINBERGER
Keyword(s):  
Comparative Study ◽  
Anterior Pituitary ◽  
Male Rats ◽  
Leucine Incorporation ◽  
Experimental Conditions ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Endogenous Proteases ◽  
Pituitary Homogenate

SUMMARY A method has been developed for studying biosynthesis of FSH in the rat pituitary in vitro. Anterior pituitary glands were incubated with [3H]leucine; a specific and sensitive immunoprecipitation technique was used to isolate FSH from the pituitary homogenate. Total FSH content of the samples was measured by a double-antibody radioimmunoassay technique. Using this technique, a comparative study of LH and FSH synthesis in the same pituitary of adult male rats incubated for various intervals (0·5–6 h) was done. Increased incorporation of [3H]leucine into both LH and FSH with time was noted. The rate and amount of [3H]leucine incorporation into FSH was found to be higher than that into LH, indicating that either the rate of FSH synthesis is higher than that of LH or FSH has more leucine residues than LH. Greater susceptibility of LH to degradation by endogenous proteases during dialysis may also reflect less incorporation of [3H]leucine into LH. This method provides a reliable tool for evaluating FSH synthesis under various experimental conditions.

AUFTRETEN VON KASTRATIONSZELLEN IM HYPOPHYSENVORDERLAPPEN MÄNNLICHER RATTEN NACH BEHANDLUNG MIT EINEM ANTIANDROGEN

1966 ◽  
Vol 53 (1) ◽  
pp. 53-60 ◽  
Author(s):  
F. Neumann
Keyword(s):  
Pituitary Gland ◽  
Inhibitory Effect ◽  
Anterior Lobe ◽  
Male Rats ◽  
Hormone Deficiency ◽  
Pars Intermedia ◽  
Sexual Hormone ◽  
Releasing Factors

ABSTRACT Following the administration of an androgen-antagonist (1,2α-methylene-6-chloro-pregna-4,6-diene-17α-ol-3,20-dione = cyproterone) to male rats, changes are observed in the anterior lobe of the pituitary gland comparable to those which develop following removal of the gonads. The appearance of so called castration cells is very striking, particularly in the periphery, and in the area adjacent to the pars intermedia. The findings suggest that the androgen-antagonism of cyproterone also manifests itself in those receptors of the sex centre, which regulate the amount of gonadotrophin production and secretion in relation to the production of testosterone. Since endogenous testosterone can no longer exert its inhibitory effect on the sex centre, the sex centre, as in a state of sexual hormone deficiency, reacts by secreting releasing factors for gonadotrophins. Thus those cell elements in the anterior lobe of the pituitary gland are stimulated and this leads to the production of gonadotrophin.

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