Morphological Feedback Phenomenon in the Nucleus arcuatus (infundibularis) Due to Gonadal Atrophy

2015 ◽  
pp. 55-58
Author(s):  
G. Ule ◽  
K. Schwechheimer
Keyword(s):  
Gonadal Atrophy

Modification of Pineal Ultrastructure by Exogenous Hormones

1967 ◽  
Vol 25 ◽  
pp. 170-171
Author(s):  
R. A. Turner ◽  
A. E. Rodin ◽  
D. K. Roberts
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
List Type ◽  
Type Number ◽  
Pregnant Rats ◽  
Gonadal Atrophy ◽  
Pineal Ultrastructure

There have been many reports which establish a relationship between the pineal and sexual structures, including gonadal hypertrophy after pinealectomy, and gonadal atrophy after injection of pineal homogenates or of melatonin. In order to further delineate this relationship the pineals from 5 groups of female rats were studied by electron microscopy:ControlsPregnant ratsAfter 4 weekly injections of 0.1 mg. estradiol benzoate.After 8 daily injections of 150 mcgm. melatonin (pineal hormone).After 8 daily injections of 3 mg. serotonin (melatonin precursor).No ultrastructural differences were evident between the control, and the pregnancy and melatonin groups. However, the estradiol injected animals exhibited a marked increase in the amount and size of rough endoplasmic reticulum within the pineal cells.

Seasonal reproduction and gonadal function: A focus on humans starting from animal studies

2021 ◽  
Author(s):  
Ester Beltran-Frutos ◽  
Livio Casarini ◽  
Daniele Santi ◽  
Giulia Brigante
Keyword(s):  
Animal Studies ◽  
Current Knowledge ◽  
Seasonal Pattern ◽  
Human Reproduction ◽  
Gonadal Function ◽  
Functional Changes ◽  
Morphological Variations ◽  
Gonadal Atrophy ◽  
Main Regulator ◽  
Seasonally Breeding

Abstract Photoperiod impacts reproduction in many species of mammals. Mating occurs at specific seasons to achieve reproductive advantages, such as optimization of offspring survival. Light is the main regulator of these changes during the photoperiod. Seasonally breeding mammals detect and transduce light signals through extraocular photoreceptor, regulating downstream melatonin-dependent peripheral circadian events. In rodents, hormonal reduction and gonadal atrophy occur quickly, and consensually with short-day periods. It remains unclear whether photoperiod influences human reproduction. Seasonal fluctuations of sex hormones have been described in humans, although they seem to not imply adaptative seasonal pattern in human gonads. This review discusses current knowledge about seasonal changes in the gonadal function of vertebrates, including humans. The photoperiod-dependent regulation of hypothalamic–pituitary-gonadal axis, as well as morphological and functional changes of the gonads are evaluated herein. Endocrine and morphological variations of reproductive functions, in response to photoperiod, are of interest as they may reflect the nature of past population selection for adaptative mechanisms that occurred during evolution.

Exercise reduces gonadal atrophy caused by short photoperiod or blinding of hamsters

1986 ◽  
Vol 37 (1) ◽  
pp. 159-162 ◽  
Author(s):  
Finley P. Gibbs ◽  
Larry J. Petterborg
Keyword(s):  
Short Photoperiod ◽  
Gonadal Atrophy

Production of Antiserum to LH-Releasing Hormone (LH-RH) Associated with Gonadal Atrophy in Rabbits: Development of Radioimmunoassays for LH-RH

Endocrinology ◽  
1973 ◽  
Vol 93 (5) ◽  
pp. 1092-1103 ◽  
Author(s):  
A. ARIMURA ◽  
H. SATO ◽  
T. KUMASAKA ◽  
R.B.fun WOROBEC ◽  
L. DEBELJUK ◽  
...  
Keyword(s):  
Releasing Hormone ◽  
Gonadal Atrophy ◽  
Lh Rh ◽  
Lh Releasing Hormone

scholarly journals Atm Inactivation Results in Aberrant Telomere Clustering during Meiotic Prophase

1999 ◽  
Vol 19 (7) ◽  
pp. 5096-5105 ◽  
Author(s):  
Tej K. Pandita ◽  
Christoph H. Westphal ◽  
Melanie Anger ◽  
Satin G. Sawant ◽  
Charles R. Geard ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Nuclear Matrix ◽  
Meiotic Prophase ◽  
Nuclear Periphery ◽  
Early Prophase ◽  
Telomeric Dna ◽  
Gonadal Atrophy ◽  
Significant Difference ◽  
Atm Protein ◽  
And Control

ABSTRACT A-T (ataxia telangiectasia) individuals frequently display gonadal atrophy, and Atm −/− mice show spermatogenic failure due to arrest at prophase of meiosis I. Chromosomal movements take place during meiotic prophase, with telomeres congregating on the nuclear envelope to transiently form a cluster during the leptotene/zygotene transition (bouquet arrangement). Since the ATM protein has been implicated in telomere metabolism of somatic cells, we have set out to investigate the effects of Atm inactivation on meiotic telomere behavior. Fluorescent in situ hybridization and synaptonemal complex (SC) immunostaining of structurally preserved spermatocytes I revealed that telomere clustering occurs aberrantly inAtm −/− mice. Numerous spermatocytes ofAtm −/− mice displayed locally accumulated telomeres with stretches of SC near the clustered chromosome ends. This contrasted with spermatogenesis of normal mice, where only a few leptotene/zygotene spermatocytes I with clustered telomeres were detected. Pachytene nuclei, which were much more abundant in normal mice, displayed telomeres scattered over the nuclear periphery. It appears that the timing and occurrence of chromosome polarization is altered in Atm −/− mice. When we examined telomere-nuclear matrix interactions in spermatocytes I, a significant difference was observed in the ratio of soluble versus matrix-associated telomeric DNA sequences between meiocytes ofAtm −/− and control mice. We propose that the severe disruption of spermatogenesis during early prophase I in the absence of functional Atm may be partly due to altered interactions of telomeres with the nuclear matrix and distorted meiotic telomere clustering.

PRODUCTION OF ANTISERUM TO LH-RELEASING HORMONE (LH-RH) ASSOCIATED WITH GONADAL ATROPHY IN RABBITS

1974 ◽  
Vol 29 (8) ◽  
pp. 556-557
Author(s):  
A. ARIMURA ◽  
H. SATO ◽  
T. KUMASAKA ◽  
R. B. WOROBEC ◽  
L. DEBELJUK ◽  
...  
Keyword(s):  
Releasing Hormone ◽  
Gonadal Atrophy ◽  
Lh Rh ◽  
Lh Releasing Hormone

scholarly journals Cellular aspects of gonadal atrophy in P-M hybrid dysgenesis

2016 ◽  
Author(s):  
Natalia Dorogova ◽  
Elena Bolobolova ◽  
Lyudmila Zakharenko
Keyword(s):  
Cell Death ◽  
Germ Cell ◽  
Elevated Temperatures ◽  
Cell Formation ◽  
Hybrid Dysgenesis ◽  
Cell Degeneration ◽  
Early Stages ◽  
Cell Death Pathways ◽  
Gonadal Atrophy ◽  
Mitochondrial Pathology

Gonadal atrophy is the most typical and dramatic manifestation of intraspecific hybrid dysgenesis syndrome leading to sterility of Drosophila melanogaster dysgenic progeny. The P-M system of hybrid dysgenesis is primarily associated with germ cell degeneration during the early stages of Drosophila development at elevated temperatures. In the present study, we have defined the phase of germ cell death as beginning at the end of embryogenesis immediately following gonad formation. The early stages of germ cell formation in dysgenic flies showed sensitivity to developmental temperature increases at any stage of the Drosophila life cycle including the imago. Analysis of germ cell reactions to hybrid dysgenesis induction revealed significant changes in subcellular structure, especially mitochondria, prior to germ cell breakdown. The mitochondrial pathology can be the reason for the activation of cell death pathways in dysgenic germ cells and lead to gonadal atrophy.

scholarly journals New Prospects in Neutering Male Animals Using Magnetic Nanoparticle Hyperthermia

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1465
Author(s):  
José Luiz P. R. Jivago ◽  
Juliana Lis Mendes Brito ◽  
Gustavo Capistrano ◽  
Marcus Vinícius-Araújo ◽  
Ediron Lima Verde ◽  
...  
Keyword(s):  
Magnetic Nanoparticle ◽  
Irreversible Process ◽  
Animal Health ◽  
Ferrite Nanoparticles ◽  
Manganese Ferrite ◽  
Gonadal Atrophy ◽  
Surgical Sterilization ◽  
Stromal Tissue ◽  
Magnetic Nanoparticle Hyperthermia ◽  
Huge Challenge

Controlling populations of free-roaming dogs and cats poses a huge challenge worldwide. Non-surgical neutering strategies for male animals have been long pursued, but the implementation of the procedures developed has remained limited to date. As submitting the testes to high temperatures impairs spermatogenesis, the present study investigated localized application of magnetic nanoparticle hyperthermia (MNH) to the testicles as a potential non-surgical sterilization method for animals. An intratesticular injection of a magnetic fluid composed of manganese-ferrite nanoparticles functionalized with citrate was administered followed by testicle exposure to an alternate magnetic field to generate localized heat. Testicular MNH was highly effective, causing progressive seminiferous tubule degeneration followed by substitution of the parenchyma with stromal tissue and gonadal atrophy, suggesting an irreversible process with few side effects to general animal health.

scholarly journals Meiotic Telomere Distribution and Sertoli Cell Nuclear Architecture Are Altered in Atm- andAtm-p53-Deficient Mice

2000 ◽  
Vol 20 (20) ◽  
pp. 7773-7783 ◽  
Author(s):  
Harry Scherthan ◽  
Martin Jerratsch ◽  
Sonu Dhar ◽  
Y. Alan Wang ◽  
Stephen P. Goff ◽  
...  
Keyword(s):  
Ataxia Telangiectasia ◽  
Meiotic Prophase ◽  
Nuclear Periphery ◽  
Nuclear Architecture ◽  
Gonadal Atrophy ◽  
Atm Protein ◽  
Genotoxic Insult ◽  
Atm Signaling ◽  
Deficient Mice

ABSTRACT The ataxia telangiectasia mutant (ATM) protein is an intrinsic part of the cell cycle machinery that surveys genomic integrity and responses to genotoxic insult. Individuals with ataxia telangiectasia as well as Atm −/− mice are predisposed to cancer and are infertile due to spermatogenesis disruption during first meiotic prophase. Atm −/−spermatocytes frequently display aberrant synapsis and clustered telomeres (bouquet topology). Here, we used telomere fluorescent in situ hybridization and immunofluorescence (IF) staining of SCP3 and testes-specific histone H1 (H1t) to spermatocytes of Atm- and Atm-p53-deficient mice and investigated whether gonadal atrophy in Atm-null mice is associated with stalling of telomere motility in meiotic prophase. SCP3-H1t IF revealed that mostAtm−/− p53 −/− spermatocytes degenerated during late zygotene, while a few progressed to pachytene and diplotene and some even beyond metaphase II, as indicated by the presence of a few round spermatids. InAtm−/− p53 −/− meiosis, the frequency of spermatocytes I with bouquet topology was elevated 72-fold. Bouquet spermatocytes with clustered telomeres were generally void of H1t signals, while mid-late pachytene and diploteneAtm−/− p53 −/− spermatocytes displayed expression of H1t and showed telomeres dispersed over the nuclear periphery. Thus, it appears that meiotic telomere movements occur independently of ATM signaling. Atm inactivation more likely leads to accumulation of spermatocytes I with bouquet topology by slowing progression through initial stages of first meiotic prophase and an ensuing arrest and demise of spermatocytes I. Sertoli cells (SECs), which contribute to faithful spermatogenesis, in theAtm mutants were found to frequently display numerous heterochromatin and telomere clusters—a nuclear topology which resembles that of immature SECs. However,Atm −/− SECs exhibited a mature vimentin and cytokeratin 8 intermediate filament expression signature. Upon IF with ATM antibodies, we observed ATM signals throughout the nuclei of human and mouse SECs, spermatocytes I, and haploid round spermatids. ATM but not H1t was absent from elongating spermatid nuclei. Thus, ATM appears to be removed from spermatid nuclei prior to the occurrence of DNA nicks which emanate as a consequence of nucleoprotamine formation.

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