Interactions of Pinealectomy and Short-Photoperiod Exposure on the Neuroendocrine Axis of the Male Syrian Hamster

1984 ◽  
Vol 38 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Richard W. Steger ◽  
Russel J. Reiter ◽  
Theresa M. Siler-Khodr
1986 ◽  
Vol 43 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Richard W. Steger ◽  
Kathleen S. Matt ◽  
Andrzej Bartke

2018 ◽  
Vol 53 (5) ◽  
pp. 1041-1051 ◽  
Author(s):  
Jesús Martínez-Hernández ◽  
Vicente Seco-Rovira ◽  
Ester Beltrán-Frutos ◽  
Concepción Ferrer ◽  
Manuel Canteras ◽  
...  

Endocrine ◽  
1996 ◽  
Vol 4 (3) ◽  
pp. 223-231 ◽  
Author(s):  
Marlena Juszczak ◽  
Richard W. Steger ◽  
Luciano Debeljuk ◽  
Clare Fadden ◽  
Jaladanki N. Rao ◽  
...  

1997 ◽  
Vol 42 (3) ◽  
pp. 221-225 ◽  
Author(s):  
Marlena Juszczak ◽  
Luciano Debeljuk ◽  
Bozena Stempniak ◽  
Richard W Steger ◽  
Clare Fadden ◽  
...  

2005 ◽  
Vol 288 (1) ◽  
pp. R234-R242 ◽  
Author(s):  
Jerome S. Menet ◽  
Patrick Vuillez ◽  
Daniel Bonn ◽  
Aurore Senser ◽  
Paul Pévet

In the Syrian hamster, winter seasonal inhibition of reproduction occurs in response to decreasing day length. This inhibitory response is modulated by nonphotic cues. In particular, access to a running wheel has been shown to produce incomplete gonadal regression. The present study sought to determine whether this occurs as a consequence of wheel effect on adaptation of the circadian system to short days or whether downstream physiological responses are involved. Short-day adaptation of the circadian clock, which is located in the suprachiasmatic nucleus (SCN) of the hypothalamus, was tested by lengthening the photosensitive phase of the SCN (assayed by light-induced c-Fos expression in the SCN) as a parameter. We found that wheel-running activity does not inhibit the integration of the photoperiodic change by the SCN even if complete testicular regression is prevented. Moreover, this exercise was even capable of accelerating the lengthening of the photosensitive phase after the transfer to short day length. Thus, although wheel-running activity inhibits the short photoperiod-induced gonadal regression, it acts on the SCN to accelerate the integration of the photoperiodic change by the biological clock.


1985 ◽  
Vol 17 (02) ◽  
pp. 107-108 ◽  
Author(s):  
S. Webb ◽  
T. Champney ◽  
M. Vaughan ◽  
R. Reiter

Andrologia ◽  
2018 ◽  
Vol 51 (1) ◽  
pp. e13148 ◽  
Author(s):  
Jesús Martínez-Hernández ◽  
Vicente Seco-Rovira ◽  
Ester Beltrán-Frutos ◽  
Concepción Ferrer ◽  
María Isabel Serrano-Sánchez ◽  
...  

2019 ◽  
Vol 102 (3) ◽  
pp. 588-597 ◽  
Author(s):  
Jesús Martínez-Hernández ◽  
Vicente Seco-Rovira ◽  
Ester Beltrán-Frutos ◽  
Concepción Ferrer ◽  
María Isabel Serrano-Sánchez ◽  
...  

Abstract The Sertoli cell (Sc) has been described as a quiescent cell once the animal has reached sexual maturity. Syrian hamster is an animal that displays testicular regression due to short photoperiod, during which process germ cells and Sc are removed through apoptosis. The aim of this work was to investigate histochemically whether the spontaneous testicular recrudescence processes after exposure to a short photoperiod lead to an increase in Sc proliferative activity in order to restore the normal population. Three spontaneous recrudescence groups were established: initial (IR), advanced (AR), and total (TR) recrudescence, which were compared with animal undergoing the regression process (mild: MRg, strong: SRg, and total: TRg) and animals in long photoperiod (Controls). Histological sections were submitted to histochemical techniques for detecting apoptotic and proliferative Sc with bright-field and fluorescence microscopy. For each group, the proliferative Sc index (PScI) and apoptotic Sc index (AScI), and the total number of Sc were obtained. The results revealed the existence of Vimentin+/TUNEL+ as well as Vimentin+/PCNA+ cells. The PScI was significantly higher in TRg and IR than in the other groups. The AScI was only significantly higher in MRg and SRg with respect to the other groups. The total number of Sc increased among TRg, IR, and AR, reaching values similar to those of the Controls. In conclusion, the increase in Sc proliferation from final regression and recrudescence, accompanied by a similar rate of apoptosis to the Control group, is the cause of the restoration of the Sc population during spontaneous recrudescence.


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