Assessment of urine and fecal estradiol and progesterone metabolite excretion in chinchilla females.

BUSSO JM; PONZIO MF; FIOL DE CUNEO M; RUIZ RD

Temuco, Chile

Jornada; V Jornadas Internacionales de Medicina Reproductiva y Biología de la Reproducción.; 2004

Facultad de Medicina, Universidad de la Frontera.

A number of non-invasive techniques are available for monitoring reproductive functions in several mammalian species, but none for Chinchillidae rodents (an endemic South American family) such as domestic and wild (CITES I) chinchilla. Our experiments were designed to study the excretion of estradiol and progesterone (time course and proportions excreted in urine or feces) in Chinchilla lanigera females. Each adult domestic female (n= 4) was injected (i. p.) with 0.80 µCi 3H-estradiol (3H-E2) plus 3.1 mg unlabeled E2, and simultaneously with 0.30 µCi 14C-progesterone (14C-P4) plus 4.2 mg of unlabelled P4. All urine and fecal samples were collected for the following 6 days postinjection. Total radioactivity and water or ether soluble metabolite forms were evaluated by differential ether / water extraction of peak radioactive samples. In urine, 71.7 ± 12.1 % of 3H-E2 metabolites were excreted, while 14C-P4 metabolites were detected in a higher proportion in feces (56.2 ± 14.9 %). Peak urinary excretion of 3H-E2  or 14C-P4 was reached at 7.0 ± 0.6 and 44.0 ± 4.0 hours postinfusion, respectively. Peak radioactivity in feces was detected later for both hormones. Reliable knowledge about reproductive physiology of chinchillas should help to apply assisted reproductive techniques in this species.