The effects of sex hormones on the size of intestinal lipoproteins

Figures

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  FIGURE 1. Particle size of lipoproteins from the lymph of mice that were intraduodenally infused with glucose/saline solution. Female (n = 5) and male (n = 4) mice were intraduodenally infused with glucose/saline solution and their intestinal lymph was collected for 1 hour. The lipoproteins in the collected lymph were then analyzed by a transmission electron microscope. The representative lipoprotein micrographs of the female (A) and male (B) mice, their lipoprotein size distribution (C), and their lipoprotein average size (D) are depicted. Scale bars are 500 nm. Values are means ± standard errors.

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  FIGURE 2. Particle size of lipoproteins from the lymph of mice that were intraduodenally infused with lipid emulsion. Female (n = 5) and male (n = 4) mice were intraduodenally infused with lipid emulsion for 6 h and their lipoproteins from the intestinal lymph collected at the 6th hour were analyzed by a transmission electron microscope. The representative lipoprotein micrographs of the female (A) and male (B) mice, their lipoprotein size distribution (C), and their lipoprotein average size (D) are depicted. Scale bars are 500 nm. Values are means ± standard errors. The asterisk sign indicates that p < 0.05 (two-tailed t-test).

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  FIGURE 3. The dose-dependent effects of estrogen on intestinal lipoproteins. Using a semipermeable membrane system, the differentiated Caco-2 cells (n ≥ 14) were incubated for 4 h with lipid mixture in their apical compartment and 0, 50, 100, or 200 pg/mL of estrogen in their basolateral compartment. The lipoproteins were then isolated from their basolateral media by using NaCl gradient ultracentrifugation. The lipoprotein TG (A), ApoB (B), and TG/ApoB ratios (C) are depicted. The TG/ApoB ratios represent the sizes of lipoproteins. Values are means ± standard errors. The asterisk sign indicates that p < 0.05 (one-way ANOVA).

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  FIGURE 4. The dose-dependent effects of progesterone on intestinal lipoproteins. Using a semipermeable membrane system, the differentiated Caco-2 cells (n ≥ 14) were incubated for 4 h with lipid mixture in their apical compartment and 0, 0.5, 1, or 10 ng/mL of progesterone in their basolateral compartment. The lipoproteins were then isolated from their basolateral media by using NaCl gradient ultracentrifugation. The lipoprotein TG (A), ApoB (B), and TG/ApoB ratios (C) are depicted. The TG/ApoB ratios represent the sizes of lipoproteins. Values are means ± standard errors. The asterisk sign indicates that p < 0.05 (one-way ANOVA).

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  FIGURE 5. The dose-dependent effects of testosterone on intestinal lipoproteins. Using a semipermeable membrane system, the differentiated Caco-2 cells (n ≥ 14) were incubated for 4 h with lipid mixture in their apical compartment and 0, 3, 6, or 9 ng/mL of testosterone in their basolateral compartment. The lipoproteins were then isolated from their basolateral media by using NaCl gradient ultracentrifugation. The lipoprotein TG (A), ApoB (B), and TG/ApoB ratios (C) are depicted. The TG/ApoB ratios represent the sizes of lipoproteins. Values are means ± standard errors. The asterisk signs indicate that p < 0.05 (one-way ANOVA).

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  FIGURE 6. The effects of ovarian cycle on intestinal lipoproteins. Using a semipermeable membrane system, the differentiated Caco-2 cells (n ≥ 12) were incubated with lipid mixture in their apical compartment and sex hormone mixture or vehicle (control) in their basolateral compartment. The concentrations of the sex hormones used resembled those in men and different phases of the ovarian cycle (See Table 1). After 4 h of incubation, the lipoproteins were isolated from the basolateral media by using NaCl gradient ultracentrifugation. The lipoprotein TG (A), ApoB (B), and TG/ApoB ratios (C) are depicted. The TG/ApoB ratios represent the sizes of lipoproteins. Values are means ± standard errors. The asterisk signs indicate that p < 0.05 (one-way ANOVA; Tukey post hoc tests were only performed when one-way ANOVA showed statistical significance).

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  FIGURE 7. Particle size of lipoproteins from Caco-2 cells treated with the combination of sex hormones that resemble men and different phases of ovarian cycle. Using a semipermeable membrane system, the differentiated Caco-2 cells were incubated with lipid mixture in their apical compartment and sex hormone mixture in their basolateral compartment. The concentrations of the sex hormones used resembled those in men and different phases of the ovarian cycle (See Table 1). After 4 h of incubation, the lipoproteins were isolated from the basolateral media by using NaCl gradient ultracentrifugation, and then analyzed by a transmission electron microscope. The representative lipoprotein micrographs of the follicular phase (A), ovulatory phase (B), luteal phase (C), and male (D) are depicted. Lipoprotein size distribution (E) and average size (D) are also presented. Scale bars are 0.1 μm (100 nm). Values are means ± standard errors. The asterisk signs indicate that p < 0.05 (one-way ANOVA followed by Tukey post hoc tests).