geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Absence of daily cycles in plasma sex steroids in male and female tuatara (Sphenodon punctatus), and the effects of acute capture stress on females


, : Absence of daily cycles in plasma sex steroids in male and female tuatara (Sphenodon punctatus), and the effects of acute capture stress on females. General and Comparative Endocrinology 79(1): 103-113

The possible existence of daily cycles in plasma concentrations of sex steroids was examined in wild male and female tuatara (Sphenodon punctatus). Samples were collected from freshly captured animals at dusk, middle of the night, dawn, and middle of the day in January (summer) and July (winter). Males showed daily cycles in mean body temperature (Tb) in both seasons but no daily cycle in mean plasma testosterone concentration in either season. Vitellogenic female tuatara in January and females in mixed reproductive condition in July also showed significant daily variation in Tb. However, there were no daily cycles in mean plasma concentrations of estradiol, testosterone, or progesterone in either group of females. Vitellogenic female tuatara subjected to an acute capture stress (3-hr confinement) in January had mean plasma concentrations of estradiol and testosterone that did not differ from those of free-roaming females. However, progesterone and Tb were significantly higher in captives than in free-roaming females. The elevation in progesterone may result from physical confinement, the difference in Tb, or both. These data suggest that seasonal fluctuations in circulating concentrations of plasma sex steroids in tuatara can be determined using samples collected at different times of the 24-hr cycle. However, the effects of acute capture stress and/or changes in Tb on plasma progesterone concentrations need to be considered in future studies on this and possibly other female reptiles.

US$29.90

PMID: 2354772


Other references

Aprile, M.; Halloran, P.; Haddad, G.; Robinette, M., 1981: Autoantibody against fibroblasts in renal transplant recipients: analysis by 51Cr-release assays. In testing for donor-specific alloantibody in renal transplantation we discovered that sera of many recipients lysed their own fibroblasts in complement-dependent cytotoxicity. The incidence of this autoreactivity before and during the first month...

Mountz, J.D.; Raveche, E.S.; Noguchi, P.D.; Steinberg, A.D., 1984: Studies of immune defective RIII/AnN mice. The present study advances our knowledge of the newly described immunodeficient RIII/AnN mouse. This strain was found to have markedly reduced spleen size and low serum levels of IgM, IgA, IgG1, IgG2 alpha, and IgG2 beta. Studies of F2 and backcro...

Copley, R.R.; Doerks, T.; Letunic, I.; Bork, P., 2002: Protein domain analysis in the era of complete genomes. Domains present one of the most useful levels at which to understand protein function, and domain family-based analysis has had a profound impact on the study of individual proteins. Protein domain discovery has been progressing steadily over the...

Quintini, C.; Spaggiari, M.; Hashimoto, K.; Aucejo, F.; Diago, T.; Fujiki, M.; Winans, C.; D'Amico, G.; Trenti, L.; Kelly, D.; Eghtesad, B.; Miller, C., 2015: Safety and effectiveness of renoportal bypass in patients with complete portal vein thrombosis: an analysis of 10 patients. The presence of portal vein thrombosis (PVT) is still considered by many transplantation centers to be an absolute contraindication to liver transplantation because of the technical difficulties that it can present and its association with a highe...

Sheila, V.K.; Moss, J.P.; Gowda, C.L.L.; Rheenen, H.A. van, 1992: Interspecific hybridization between Cicer arietinum and wild Cicer species. Twenty-eight interspecific crosses between 8 elite C. arietinum genotypes as females and 6 accessions of 5 wild Cicer spp. as male parents were attempted during the 1988-89 and 1989-90 growing seasons. Work was conducted in a greenhouse with exoge...

Hossain, S.M.; Barreto, S.L.T., 1995: Effect of dietary protein and vitamin E on productive and reproductive performance of broiler breeders. Poultry Science 74(SUPPL 1): 67

Goldschmidt V.M., 1933: Otto Muegge. Pages 42-46 1933

Bachar, O.; Adner, M.; Uddman, R.; Cardell, L-Olaf., 2005: Prolonged exposure to NT-3 attenuates cholinergic nerve-mediated contractions in cultured murine airways. Chronic airway inflammation may induce subsequent airway hyper-responsiveness (AHR) including pathological alteration of neural activity. Asthmatic airways contain elevated levels of neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDN...

Garges, S.; Adhya, S., 1988: Cyclic AMP-induced conformational change of cyclic AMP receptor protein (CRP): intragenic suppressors of cyclic AMP-independent CRP mutations. We isolated and characterized crp mutations in Escherichia coli that allow cyclic AMP (cAMP) receptor protein to function without cAMP. These mutants defined a region involved in the cAMP-induced allosteric change of cAMP receptor protein that is...

Sherman, C.B.; Tosteson, T.D.; Tager, I.B.; Speizer, F.E.; Weiss, S.T., 1990: Early childhood predictors of asthma. To investigate potential risk factors for the development of childhood asthma, the authors undertook a longitudinal study using a cohort of 770 children aged 5-9 years from East Boston, Massachusetts, (USA) that has been under study since 1975. Th...