Follicles development in the foetal human ovary

Summary In the foetal human ovary, diameters of oocyte and follicle, as well as those of oocyte and nucleus, are found to be positively and linearly correlated with each other. Follicle diameter and number of granulosa cells also show a positive and linear relationship. Finally, in all ovaries examined, from 5 months after conception onwards, small antral follicles were assessed.     

Follicles development in the foetal human ovary.

In the foetal human ovary, diameters of oocyte and follicle, as well as those of oocyte and nucleus, are found to be positively and linearly correlated with each other. Follicle diameter and number of granulosa cells also show a positive and linear relationship. Finally, in all ovaries examined, from 5 months after conception onwards, small antral follicles were assessed.     

Apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pig ovaries

The porcine antral follicles, 3–6 mm in diameter, were dissected from the ovaries of mature pigs, and then granulosa and cumulus cells were isolated from each follicle. In atretic follicles, high activity of neutral Ca²⁺/Mg²⁺-dependent endonuclease and DNA ladder formation, estimated by electrophoresis, were noted in granulosa cells but not in cumulus cells. Extremely low activity of the endonuclease and no DNA ladder formation were observed in both types of cells obtained from healthy follicles. Moreover, apoptotic cells were observed histochemically among granulosa cells only. A good correlation (r=0.987) between the endonuclease activity of granulosa cells and the progesterone/estradiol ratio of follicular fluid in each follicle was found. These results suggest that apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pigs.     

Abnormal organization of ovarian follicles in the mutantl(1)su(f) mad-ts ofDrosophila melanogaster

Summary The morphology of ovarian follicles in the temperature-sensitive female-sterile mutantl(1)su(f) ^mad-ts has been studied by means of light and electron microscopy. As the follicle cells gradually degenerate at the restrictive temperature (29°C) the follicles become increasingly disorganized with respect to shape and polarity.Acknowledgments. This work was supported by the Deutsche Forschungsgemeinschaft (SFB 46). We wish to thank Mrs R. Koppa for excellent technical assistance and Mrs G. Mahlke for photographic work. We are also indebted to Dr D. Zissler, Dr E. Gateff and Prof. K. Sander for many helpful suggestions.     

Origin of ovarian follicle cells in birds

Summary In the embryonic Japanese quail ovary, transplanted on chicken chorioallantoic membrane (CAM), follicle cells are derived from somatic cells of the ovarian surface epithelium. No evidence was found for a contribution of other cell groups of the quail ovary in the formation of follicle cells. This may be demonstrated on PAS stained sections, by following the transfer of carbon particles, initially applied on the surface epithelium.The author is very grateful to Prof.L. Vakaet, R.U.C.A. Antwerp, for his valuables suggestions, and to MissC. van Hoecke for her technical assistance.     

Surface topography of granulosa cells accompanied by fragmented oocytes

Scanning electron microscopy of granulosa cells (GC) and granulosa cell-like structures (GCLS) revealed that both had lacy foldings, or plicae, on the surface and were identical. The plicae did not always cover the entire surface of GC or GCLS. Both structures were interconnected by multivalent processes.     

Inhibition of the preovulatory secretion of gonadotropins by prolactin in rats seems to depend on the strain used

Intraperitoneal injection of Rat Prolactin to cyclic female Rats results in preovulatory changes which depend on the strain of animals. Specifically, preovulatory surges of luteinizing hormone and follicle stimulating hormone were suppressed in Sprague-Dawley Rats while delayed but enhanced preovulatory surges of both gonadotropins were observed in Wistar strain.     

Strukturelle und funktionelle Veränderungen am menschlichen Ovar unter Einwirkung hormonaler Antikonzeptiva

Summary In two cases, a fresh corpus luteum was found during treatment with hormonal anticonceptiva (Lyndiol 2.5^®). The decreased excretion of all oestrogen fractions can be explained by the lack of proliferation of the theca interna. The striking proliferation of the follicle epithelium after the completed ovulation is as yet an unexplained phenomenon. The possible endocrine actions of such steroid combinations upon the pituitary are discussed. Further investigations are in progress.     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Actin- and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.     

Einbau von H3-d-glucose während der Oogenese beiApis mellifica L.

Summary The incorporation of tritiated glucose into the ovary of honey bee queens was studied by autoradiography. During the last stages of oogenesis, the synthesis of respectable amounts of glycogen was found in the reticuloplasm of the developing eggs. The follicle epithelium and also the nurse cells only appeared more lightly and transitory labelled at medium stages. An hypothesis was established concerning an antagonism of protein and polysaccharide formation in the cytoplasm corresponding to the rather late occurrence of glycogen in insect oogenesis.     

HCG-insensitivity of the postnatal rat ovary is due to the lack of a specific receptor

Summary Rat ovary is insensitive to luteinizing hormone and human chorionic gonadotrophin till to the 8th to 10th day of postnatal development. This insensitivity is due to the lack of a specific hormone receptor.This work was supported in part by the Deutsche Forschungsgemeinschaft (SFB 46). Purified HCG was a gift of Schering AG, Berlin-West. We thank Dr F. Peters for performing the iodination of HCG.     

Immunocytochemical demonstration of contractile cells in the human ovarian follicle

Summary Actin-and myosin-like immunoreactivity is found in cells located in the theca externa of the follicle wall of the human ovary, and corresponding to previously observed myoid cells. The immunocytochemical observation provides direct structural evidence that non-vascular contractile cells are also present in the follicle wall in humans. As expected, perifollicular blood vessels showed a positive immunoreaction for actin and myosin in their smooth muscle walls.This work was supported by the Swedish Medical Research Council, grant No. 14X-732/5680.     

Bakterien im Ovar aquariengehälterter Meeresfische

Summary In the ovary of the ovoviviparous teleostZoarces viviparus L. kept in aquaria, gram-negative bacteria are found. These penetrate the tissue up to the basement membrane which separates the follicle epithelium from the theca.

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Der Deutschen Forschungsgemeinschaft danke ich für die Förderung der Arbeiten, Herrn Prof. Dr.,P. Giesbrecht, Berlin, für Beratung.     

Autoradiographic analysis of FSH binding during follicular atresia

Binding of FSH to ovarian cells was studied in PMSG primed immature Swiss mice, 48 h after PMSG treatment, FSH-binding was higher in the periphery than in the cumulus cells of the antral follicles. Binding of FSH to granulosa cells of normal follicles was observed to be specific, 48 h after PMSG injection. No localization in the atretic follicles could be seen by autoradiography 72 h after priming.     

Morphogenesis and hormonogenesis in vitro of granulosa cells of the European badger Meles meles L.]

Granulosa cells harvested from follicles of Badger during inactive luteal phaseluteinize in vitro. The results demonstrate that the serum's origin influence progesteron production of Badger's granulosa cells in culture. LH appears equally to be stimulating.     

Untersuchungen über Ultrastruktur und Aminosäurenzusammensetzung der Eischalen vonNatrix natrix

Summary The ultrastructures of eggshells ofNatrix natrix and the membrana testacea ofGallus gallus dom. are very similar, with the exception of cavity systems which only exist in eggshells of snakes (ringsnake) but not in the membrana testacea of birds. In the sheath of the fibres ofNatrix natrix, a positive ruthenium redreaction indicates the presence of mucopolysacharides, or proteoglycans. The eggshells ofNatrix natrix contain a high proportion of proline, but also of cystine, histidine and arginine. The high proline content is discussed with regard to the properties of poly-l-proline. Presumably proteins similar to collagen exist in eggshells ofNatrix natrix.     

Virus-like particles in the opossum submandibular gland

Summary Numerous inclusion bodies (virus-like particles) were observed in the lumina of the intercellular canaliculi, mucous tubules and intralobular ducts of the opossum submandibular gland. The particles are spherical in outline, show an electron dense core, and are surrounded by a peripheral membrane.     

On fragmentation and elimination of ovarian oocytes

Summary Examination of numerous fragmented oocytes in the ovary revealed an asynchronous relationship between nuclear and cell divisions. The asynchrony was observed in non-fragmented oocytes as well and was considered to be one of the common processes leading towards oocyte elimination in the ovary. The present study additionally demonstrates the morphology of follicle cell degeneration observed on the surface of fragmented oocytes.The authors are very grateful to Mr T. Horii, Dr K. Takeda, Dr S. Morisawa, Mr K. Takahashi, Mr Y. Matsumoto and Mrs M. Shinohara for their laboratory help.     

Immunocytochemical anatomy of alpha granules in the human endocrine pancreas]

Using the sensitive protein A-gold technique for the demonstration of antigenic sites in thin section for electron microscopy it was found that in the alpha granules of human pancreas, glucagon immunoreactivity (specific, C-terminal) is restricted to the dense granule core while glicentin immunoreactivity predominates on the peripheral halo surrounding the dense core.     

Hormonal control of mammalian oocyte meiosis at diplotene stage

Mammalian oocytes grow and undergo meiosis within ovarian follicles. Fully grown oocytes are arrested at the first meiotic prophase by a mural granulosa origin “arrester” until a surge of luteinizing hormone (LH) from the pituitary at the mid-cycle stimulates the immature oocyte to resume meiosis. Recent evidence indicates that natriuretic peptide precursor type C (NPPC) produced by mural granulosa cells stimulates the generation of cyclic guanosine 3′,5′-monophosphate (cGMP) by cumulus cell natriuretic peptide receptor 2 (NPR2), which diffuses into oocyte via gap junctions and inhibits oocyte phosphodiesterase 3A (PDE3A) activity and cyclic adenosine 3′,5′-monophosphate (cAMP) hydrolysis and maintains meiotic arrest with a high intraoocyte cAMP level. This cAMP is generated through the activity of the Gs G-protein by the G-protein-coupled receptor, GPR3 and GPR12, and adenylyl cyclases (ADCY) endogenous to the oocyte. Further studies suggest that endocrine hormones, such as follicle-stimulating hormone (FSH), LH, 17β-estradiol (E2) and oocyte-derived paracrine factors (ODPFs), participate in oocyte meiosis possibly by the regulation of NPPC and/or NPR2. A detailed investigation of NPPC and NPR2 expression in follicle cells will elucidate the precise molecular mechanisms of gonadotropins, and control the arrest as well as resumption of meiosis.