title: Comparison of plasma and testicular testosterone levels during the active season in the common garter snake, Thamnophis sirtalis (L).
abstract: Plasma and testicular testosterone levels were determined during three periods (spring, summer and autumn) of the active season in the common garter snake, Thamnophis sirtalis. Plasma testosterone levels were highest in spring and lowest in summer. Testicular testosterone levels were higher in spring than autumn but not significantly different in spring than summer or in summer than autumn. This study presents further evidence that in reptiles, plasma and testicular androgen cycles are not necessarily parallel.
authors.forename: M R
authors.initials: MR
authors.lastname: Weil
mesh_terms: D000818:Animals; D008297:Male; D010507:Periodicity; D012621:Seasons; D012671:Seminiferous Tubules / Q000033:anatomy & histology; D012911:Snakes / Q000378:metabolism*; D013737:Testis / Q000378:metabolism*; D013739:Testosterone / Q000097:blood / Q000378:metabolism*
chemical_list: D013739:Testosterone