Effect of photoperiod on testicular functions in male Sprague-Dawley rats.
Variation in reproductive status in response to photoperiods has been observed in laboratory rats. We investigated the effects of photoperiod on testicular activity in Sprague-Dawley rats (Rattus norvigicus) maintained in experimental photoperiodic condition. Twenty-four adult male rats weighing 170+/-10g were conditioned to different lighting conditions of Light/Dark (LD) Cycle for 6 weeks. Group 1, Control group (LD12:12, light on from 07:00hr to 19:00hr). Group 2, Short Photoperiod group (LD 8:16hr, light on from 09:00hr to 17:00hr). Group 3, Long Photoperiod group (LD 16:8hr, light on from 05:00hr to 21:00hr). A significant influence of different lighting conditions on the testicular parameters was observed. Short photoperiod showed a suppressing effect (P < 0.001) on testicular weight, sperm motility sperm viability and sperm counts, while long photoperiod had an inducing, though insignificant, effect on the measured parameters. The results confirmed that Sprague-Dawley rats are photoresponsive and changes in the photoperiod could influence their reproductive functions.
Olayaki
L A
LA
Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Kwara State, Nigeria. luqmanolayaki@yahoo.com
Soladoye
A O
AO
Salman
T M
TM
Joraiah
B
B
D000818:Animals; D008297:Male; D009929:Organ Size; D017440:Photoperiod; D051381:Rats; D017207:Rats, Sprague-Dawley; D012098:Reproduction; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology*; D013737:Testis / Q000033:anatomy & histology / Q000502:physiology*