title: Noninvasive monitoring of ovarian endocrine activity in the chinchilla (Chinchilla lanigera).
abstract: Reproductive endocrinology information is limited for Chinchilla lanigera, a South American species characterized by extremely long gestation and estrus cycle compared with others rodents. This study was designed to validate a non-invasive technique for monitoring ovarian endocrine activity. Animals were exposed indoors to natural photoperiod (31 degrees S-64 degrees W, Argentina); temperature range: 17-26 degrees C, with food and water ad libitum. Radiolabelled infusion (n=4): (3)H-estradiol ((3)H-E(2)) and (14)C-progesterone ((14)C-P(4)) were injected (i.p). Biochemical validation: HPLC-UV detector was employed to determine natural steroids in urine and fecal extracts and to determine immunoreactive metabolites. Physiological validation: (1) pregnancy (n=5): body weight and urinary and fecal steroidal metabolites were measured until birth; (2) Seasonality (n=9): urine and feces were collected in May, August, November, and February. Total (3)H-E(2) and (14)C-P(4) radioactivity recovered was 60.5+/-15.5 and 74.5+/-19.4%, respectively. After (3)H-E(2) injection, urinary radioactivity peaked at 7.0+/-0.6 hr; in contrast, urinary (14)C-P(4) excretion peaked at 44.0+/-4.0 hr (p=0.000). Peak radioactivity in feces occurred between 24-48 hr for both hormones. Several correlations were detected during pregnancy between body weight vs. urinary progestagens/day (r=0.44, p<0.03); vs. urinary progestagens/creatinine (r=0.73, p=2.9 x 10(-5)); vs. urinary estrogens/day (r=0.74; p<0.2); and vs. urinary estrogens/creatinine (r=0.74; p<2.0 x 10(-5)). On the other hand, urinary and fecal progestagen excretion exhibited significant seasonal fluctuations and urinary estrogen concentrations showed a similar pattern (p=0.062 for winter-spring vs. summer-autumn). This methodology proved to be useful for monitoring ovary endocrine activity in urine of chinchilla female.
authors.affiliation: Instituto de Fisiología, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Santa Rosa 1085, X5000ESU, Córdoba, Argentina. juanmbusso73@yahoo.com <juanmbusso73@yahoo.com>
authors.forename: Juan
authors.initials: J
authors.lastname: Manuel Busso
authors.forename: Marina
authors.initials: M
authors.lastname: Flavia Ponzio
authors.forename: Marta
authors.initials: M
authors.lastname: Fiol de Cuneo
authors.forename: Rubén
authors.initials: R
authors.lastname: Daniel Ruiz
mesh_terms: D000818:Animals; D002682:Chinchilla / Q000378:metabolism / Q000502:physiology*; D003404:Creatinine / Q000652:urine; D004958:Estradiol / Q000378:metabolism / Q000652:urine; D005243:Feces / Q000737:chemistry; D005260:Female; D008137:Longitudinal Studies; D008297:Male; D010053:Ovary / Q000378:metabolism / Q000502:physiology*; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism / Q000652:urine; D011863:Radioimmunoassay; D012621:Seasons
chemical_list: D011374:Progesterone; D004958:Estradiol; D003404:Creatinine