Early Short Photoperiod Effects in Female LSH/SsLak Syrian Hamsters*

Hauser, Ursula; Benson, Bryant

doi:10.1210/endo-120-1-239

Cited by 7 publications

(1 citation statement)

References 32 publications

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“…Our finding that LSH/SsLak hamsters show more rapid gonadal regression during exposure to short days when compared with outbred hamsters is consistent with the findings by others with both female [25] and male [26] LSH/ SsLak hamsters. However, the comparison with other inbred strains has not been made previously.…”

Section: Discussionsupporting

confidence: 92%

Photoperiodic Responses Differ among Inbred Strains of Golden Hamsters (Mesocricetus Auratus)1

Vitaterna

Turek

1993

Biology of Reproduction

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Inbred strains of golden hamsters differ in both the free-running period of the circadian rhythm of locomotor activity in constant darkness, and in the phase angle of entrainment of activity to a 14L:10D cycle. To determine whether these differences in circadian entrainment affect photoperiodic time measurement, we measured the critical photoperiod for maintaining testicular function as well as the rate of response for four different inbred strains (MHA/SsLak, LSH/SsLak, BIO 1.5, and BIO 87.20) and an outbred stock (Lak:LVG(SYR)) of golden hamsters. Hamsters of each group were maintained for 12 wk under one of five different LD cycles. Animals of all groups maintained testis size in 14L:10D and 12.5L:11.5D. Significant strain differences were observed in the critical photoperiod for maintaining testis size after 12 wk; the LSH/SsLak inbred strain showed complete testicular regression during exposure to 12L:12D, while little change was observed in any of the other strains under this photoperiod. Some degree of testicular regression was observed in all groups exposed to 11.5L:12.5D, while complete regression was observed in all animals exposed to 6L:18D. The rate of testicular regression differed markedly between the different groups under both 6L:18D and 11.5L:12.5D. The differences in critical photoperiod and rate of testicular regression observed between the various strains could not be correlated with the known strain differences in entrainment or circadian period, indicating that genetic differences in photoperiodic response are not related to the genetic differences in circadian rhythmicity.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionsupporting

confidence: 92%

Photoperiodic Responses Differ among Inbred Strains of Golden Hamsters (Mesocricetus Auratus)1

Vitaterna

Turek

1993

Biology of Reproduction

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Prolactin messenger ribonucleic acid levels, prolactin synthesis, and radioimmunoassayable prolactin during the estrous cycle in the golden syrian hamster

Massa¹,

Blask²

1990

Life Sciences

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Rapid Cessation of Estrous Cyclicity and Depressed Castration Response in Short Photoperiod-Treated, Inbred LSH/SsLak Hamsters1

Hauser¹,

Benson²

1986

Biology of Reproduction

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This study examined the effects of transfer from long photoperiod (LP) to short photoperiod (SP) on the cessation of ovarian cyclicity and the castration response in inbred LSH/SsLak golden Syrian hamsters. Forty-six 8 to 10-wk-old female hamsters were acclimatized in LP (14L:10D; lights on at 0600 h) during which time animals were monitored for regular ovarian cyclicity. Twenty-six animals were transferred to SP (8L:16D; lights on at 0600 h) and examined daily for vaginal discharges. One day after the day of the first missed ovulation, individual SP-exposed animals were bilaterally ovariectomized; concomitantly, an LP control animal in diestrus I underwent the same procedure. Thirty days after ovariectomy, the hamsters were fitted with intra-atrial silastic cannulae. On the following two postoperative days, 0.6 ml blood samples were collected at 0700, 1200, 1400, and 1600 h for SP animals and at 0700, 1400, 1600 and 1800 h for LP controls. On the third day, the animals were decapitated and sera and pituitaries saved for determination of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) by radioimmunoassay (RIA). All SP-exposed animals displayed their last estrous discharge 14-34 days after transfer to SP (mean = 23.0 +/- 0.8 days). Their ovaries were characterized by the absence of corpora lutea, the presence of large atretic antral follicles, few growing follicles, and interstitium that was stimulated to varying degrees. Total and adjusted pituitary weights were decreased by SP exposure (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

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Early Short Photoperiod Effects in Female LSH/SsLak Syrian Hamsters*

Cited by 7 publications

References 32 publications

Photoperiodic Responses Differ among Inbred Strains of Golden Hamsters (Mesocricetus Auratus)1

Photoperiodic Responses Differ among Inbred Strains of Golden Hamsters (Mesocricetus Auratus)1

Prolactin messenger ribonucleic acid levels, prolactin synthesis, and radioimmunoassayable prolactin during the estrous cycle in the golden syrian hamster

Rapid Cessation of Estrous Cyclicity and Depressed Castration Response in Short Photoperiod-Treated, Inbred LSH/SsLak Hamsters1

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