title: Serum cortisol and progestin concentrations in pregnant and non-pregnant Asian elephants (Elephas maximus).
abstract: Blood samples were collected during the estrous cycle (n=3), throughout gestation (n=3), and during the periparturient period (n=11) to assess serum concentrations of cortisol in pregnant and non-pregnant Asian elephants whose reproductive status was being monitored by serum progestin determination. While serum cortisol concentrations remained constant throughout gestation, progestin concentrations decreased significantly (p<0.05) in the second half of pregnancy, declining to undetectable levels by 3 days before calving. During the non-luteal phase of the estrous cycle serum progestins varied from undetectable levels to 100pg/ml (53+/-10.7pg/ml) then increased steadily during the luteal phase (322+/-207.5pg/ml). There were no significant differences between serum cortisol concentrations during the luteal and those of the non-luteal phase (p>0.05). The mean cortisol concentration during the estrous cycle was about twice that during pregnancy (p>0.05). No substantial changes in maternal cortisol were found during the course of pregnancy or the periparturient period.
authors.affiliation: Hormone Quantification Laboratory, Department of Animal Reproduction, Faculty of Veterinary Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: C A
authors.initials: CA
authors.lastname: Oliveira
authors.forename: E C G
authors.initials: EC
authors.lastname: Felippe
authors.forename: M O M
authors.initials: MO
authors.lastname: Chelini
mesh_terms: D000818:Animals; D001208:Asia; D004606:Elephants / Q000097:blood*; D004971:Estrus; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood*; D011372:Progestins / Q000097:blood*; D012016:Reference Values
chemical_list: D011372:Progestins; D006854:Hydrocortisone