Fig 1.
Knee passive ROM at different phases of the estrous cycle.
The knee ROM was the highest at proestrus and diestrus and the lowest at estrus. Ps- proestrus; Es-estrus; Ms; metestrus; Ds; diestrus. Data were expressed as mean ± SEM and n = 6 per study group. *p<0.05 as compared to estrus.
Fig 2.
RXFP1& RXFP2 mRNA and protein expressions in the hamstring muscles.
The expression of (A) RXFP1 mRNA (B) RXFP2 mRNA and (C) the ratio of RXFP1& RXFP2/ β-actin and Western blot images of these proteins in the hamstring muscle homogenates. The highest RXFP1 and RXFP2 mRNA and protein expressions were observed at proestrus followed by diestrus. *p<0.05 as compared to estrus for the respective isoforms. Ps-proestrus; Es-estrus; Ms; metestrus; Ds; diestrus. Data were expressed as mean ± SEM and n = 6 per study group.
Fig 3.
RXFP1& RXFP2 mRNA and protein expressions in the patellar tendon.
The expression of (A) RXFP1 mRNA (B) RXFP2 mRNA and (C) ratio of RXFP1& RXFP2/ β-actin and Western blot bands of these proteins in the patellar tendon homogenates. The mRNA and protein expression were the highest at proestrus and diestrus phases. *p<0.05 as compared to estrus and metestrus for the respective isoforms. Ps-prosterous; Es-estrus; Ms; metestrus; Ds; diestrus. Data were expressed as mean ± SEM and n = 6 per study group.
Fig 4.
RXFP1& RXFP2 mRNA and protein expression levels in the collateral ligament.
The expression of (A) RXFP1 mRNA (B) RXFP2 mRNA and (C) RXFP1 & RXFP2/β-actin and Western blot bands in the collateral ligament homogenates. The expression of mRNA and protein were the highest at proestrus followed by diestrus. *p<0.05 as compared to estrus and metestrus for the respective isoforms. Ps-proestrus; Es- estrus; Ms; metestrus; Ds; diestrus. Data were expressed as mean ± SEM and n = 6 per study group.
Fig 5.
Mean serum hormone levels are presented as mean + SEM in intact female rats.
*The level of oestrogen was the highest at proestrus (P<0.05). # The level of progesterone was the highest at diestrus and proestrus compare to estrus (P<0.05). $Meanwhile, relaxin level was the highest at diestrus compare to 3 other stages of estrous cycles (P<0.05). A strong positive correlation (r = 0.901 & p<001) was observed between serum progesterone and relaxin levels throughout the phases of the estrous cycle.
Table 1.
Serum hormone level in non ovariectomized rat at different phases of the estrous cycle.
Fig 6.
Blot analysis for validation of primary antibodies.
A distinct band at ∼80 kDa, which is consistent with the molecular weight of one isoform of the RXFP1 receptor. A distinct band at ∼80 kDA is shown RXFP2 receptor, which is consistent with the molecular weight. Western blot target bands increased with increasing of sample concentration with same antibody concentration.
Table 2.
Correlation coefficient of sex steroid and knee range of motion.