Document Detail

Reproductive cycle of the Neotropical Crotalus durissus terrificus: I. Seasonal levels and interplay between steroid hormones and vasotocinase.
MedLine Citation:
PMID:  15504392     Owner:  NLM     Status:  MEDLINE    
Crotaline snakes present delayed fertilization and sperm storage because secondary vitellogenesis is not completed by the time of mating. The release of vitellogenesis and synchrony between ovulation and fertilization suggest a steroidal modulation. We investigated changes of sexual steroid levels during reproduction in the Neotropical rattlesnake Crotalus durissus terrificus, analyzing macroscopical variations of reproductive condition (vitellogenesis, pregnancy, and post-partum) and plasma levels of estradiol, progesterone, and vasotocinase cystine aminopeptidase (CAP) activity over 2 years. Data showed 44.4% non-reproductive snakes (40.1% primary vitellogenesis and 4.3% post-partum) and 55.6% reproductive (36.8% secondary vitellogenesis and 18.8% pregnant). Estradiol was low in spring and summer, increasing in autumn till it peaked in winter. Estradiol in secondary vitellogenesis was significantly higher than in primary vitellogenesis, or in pregnant and post-partum females, Progesterone dropped significantly in autumn compared to summer, winter, and spring. Pregnant females showed the highest levels of progesterone compared to primary or secondary vitellogenesis, or post-partum females. CAP activity showed lowest values in reproductive females in autumn and greatest levels in post-partum females. A significant negative linear relationship was obtained between CAP activity and estradiol. The combination of morphological observations, levels of steroids and CAP activity allowed us to suggest a similar morphological reproductive pattern between temperate and tropical rattlesnakes, and to infer the role of estradiol, progesterone and CAP activity on vitellogenesis, gestation and sperm storage, respectively.
S M Almeida-Santos; F M F Abdalla; P F Silveira; N Yamanouye; M C Breno; M G Salomão
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  General and comparative endocrinology     Volume:  139     ISSN:  0016-6480     ISO Abbreviation:  Gen. Comp. Endocrinol.     Publication Date:  2004 Nov 
Date Detail:
Created Date:  2004-10-26     Completed Date:  2005-03-08     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370735     Medline TA:  Gen Comp Endocrinol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  143-50     Citation Subset:  IM    
Laboratório de Herpetologia, Instituto Butantan, Av. Dr. Vital Brazil 1500, Butantã 05503-900, São Paulo-SP, Brazil.
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MeSH Terms
Crotalus / physiology*
Cystinyl Aminopeptidase / blood,  pharmacology
Gonadal Steroid Hormones / blood*
Pregnancy, Animal / physiology*
Progesterone / blood
Reproduction / physiology*
Vasotocin / pharmacology*
Reg. No./Substance:
0/Gonadal Steroid Hormones; 57-83-0/Progesterone; 9034-50-8/Vasotocin; EC Aminopeptidase

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