LEPTIN CIRCADIAN RHYTHM EXPRESSION IN GOATS

• Main Authors: Mario Espinosa-Martínez, Héctor Vera-Avila, Everardo González-Padilla, Alejadro Villa-Godoy, Eugenio Villagómez-Amezcua, Héctor Jiménez-Severiano, Cesar Mejía-Guadarrama, Manuel Miranda-Anaya, Leon Cintra-McGlone
• Format: Article
• Language: English
• Published: Universidad Autónoma de Yucatán 2009-02-01
• Series: Tropical and Subtropical Agroecosystems
• Subjects: Goats, leptin, circadian rhythm
• Online Access: http://www.revista.ccba.uady.mx/ojs/index.php/TSA/article/view/109
• ISSN: 1870-0462

The objective was to determine if serum leptin expresses a circadian rhythm in goats, and the effect of body mass index (BMI) and season of the year on such expression. Eight mature, ovariectomized, female goats with s.c. sylastic implants containing 17β-estradiol were maintained in a high (HBMI, n=4) or low (LBMI, n=4) BMI during the breeding (BS-december, n=8) and transition into anestrous (TS-february, n=8) seasons. Blood samples were obtained every hour throughout a 48 h period and serum leptin determined (Linco Res. Inc.). Results were analyzed by COSINOR program (fit of data to a cosine curve) obtaining the MESOR (mean leptin concentration), AMPLITUDE (half difference between  highest and lowest leptin concentration) and ACROPHASE (time of highest leptin concentration). Frequency of occurrence of a circadian rhythm was analyzed by Fisher’s Exact test. A leptin circadian rhythm was evident (P