Serum luteinizing hormone response to administration of gonadotropin-releasing hormone to atrazine-treated gilts.
The aim of the study was to evaluate the response of porcine luteinizing hormone (pLH) in serum to a single iv administration of gonadotropin-releasing hormone (GnRH) in atrazine-treated pigs. Experiments were performed in 15 mature female pigs (10 atrazine-treated, 5 control). From the onset of estrous (day 0), the pigs were given 1 mg atrazine/kg body mass in feed for 20 d of the estrous cycle. On the last day, blood samples were collected at min 0 from control and atrazine-exposed, and 5 atrazine-exposed pigs were immediatey given 100 mg GnRH iv. Blood samples were collected from atrazine-exposed and the GnRH-injected atrazine-exposed groups at 20, 30, 40 and 90 min and serum pLH concentrations were determined by radioimmunoassay. The administration of atrazine led to significant (p< 0.001) suppression of serum pLH concentrations (0.57 +/- 0.05 ng/ml) compared to control animals (2.24 +/- 0.20 ng/ml). The single iv GnRH administration to the atrazine-exposed pigs provoked significant pLH release at 20 and 30 min after GnRH administration, indicating attenuation of GnRH release in the atrazine-exposed animals was responsible for the suppression of serum pLH.
Department of Chemistry, Croatian Veterinary Institute, Zagreb, Croatia.
Tihomira
T
Gojmerac
Jelka
J
Pleadin
Marijan
M
Zuric
Ranka
R
Rajkovic-Janje
Mirko
M
Korsic
D000818:Animals; D001280:Atrazine / Q000008:administration & dosage / Q000633:toxicity*; D004971:Estrus; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D006540:Herbicides / Q000008:administration & dosage / Q000633:toxicity*; D007262:Infusions, Intravenous; D007986:Luteinizing Hormone / Q000097:blood* / Q000187:drug effects*; D011863:Radioimmunoassay; D013552:Swine
D006540:Herbicides; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D001280:Atrazine