Estrus Period Determination of Female Rats (Rattus norvegicus) by Fourier Transform Infrared (FTIR) through Identification of Reproductive Hormones Metabolites in Urine Samples

Abstract

Recently, some fertility determination methods by determining estrus cycle through analysis of the existence and level of estradiol hormones metabolites in urine such as estrone conjugate (E1C) and pregnanediol 3 glucuronide (PdG) have been developed. Those hormone determination analyses were using destructive methods, which were complicated and highlycost. Therefore, a fertility analysis was conducted in this research by determining the E1C and PdG level using the FTIR method. The samples in this research were urine of 3 estrus and non-estrus periods of the cycle from 10 rat. Those samples were analysed by 2 methods: qualitative method with vaginal smears which observing proportion of mature and immature epithelial cells of vagina, and FTIR method. The FTIR analysis results were spectrums with absorbancy numbers which then been used to determine E1C and PdG level. The absorbancy values were compared relatively with similar creatinine values throughout the cycles. Creatinine was identified on ketone peak number 1730 cm-1. The low SD values showed that creatinine had constant values throughout the cycles. Functional group absorbance represented E1C and PdG were compared to creatinine. PdG was identified on aldehyde peak number 1639 cm-1, carboxyl acid number 1745 cm-1 and alkyl 1379 cm-1. E1C was identified on alkyl peak number 416 cm-1, aromatic 709 cm-1 and hydroxyl 3468 cm-1.