The model of compensatory growth in zebrafish. A to C: the body weight change of zebrafish during fasting and refeeding. (A) The zebrafish were fasted for 7 days and refed for 28 days. (B) The zebrafish were fasted for 14 days and refed for 21 days. (C) The zebrafish were fasted for 21 days and refed for 14 days. n = 21–22. (D) The survival rate of zebrafish which were intraperitoneally injected with S. agalactiae; F: feeding; S: starvation; R: refeeding. n = 3, *: p < 0.05, **: p < 0.01; ***: p < 0.001.

The model of compensatory growth in zebrafish. A to C: the body weight change of zebrafish during fasting and refeeding. (A) The zebrafish were fasted for 7 days and refed for 28 days. (B) The zebrafish were fasted for 14 days and refed for 21 days. (C) The zebrafish were fasted for 21 days and refed for 14 days. n = 21–22. (D) The survival rate of zebrafish which were intraperitoneally injected with S. agalactiae; F: feeding; S: starvation; R: refeeding. n = 3, *: p < 0.05, **: p < 0.01; ***: p < 0.001.

Morphological changes in the kidneys of zebrafish during fasting and refeeding. (A) HE-staining of kidney in zebrafish during fasting and refeeding. Black triangle denotes injured tubules. Red arrow denotes MMCs. Red star denotes hyaline droplets. (B) Statistic analysis of proportion of injured tubules in kidney. (C) Statistic analysis of MMCs in kidney. n = 3–4. (D) The mRNA relative expression of havcr1 gene in kidney of zebrafish during fasting and refeeding. n = 8–10. F: feeding; S: starvation; R: refeeding. *: p < 0.05.

Morphological changes in the kidneys of zebrafish during fasting and refeeding. (A) HE-staining of kidney in zebrafish during fasting and refeeding. Black triangle denotes injured tubules. Red arrow denotes MMCs. Red star denotes hyaline droplets. (B) Statistic analysis of proportion of injured tubules in kidney. (C) Statistic analysis of MMCs in kidney. n = 3–4. (D) The mRNA relative expression of havcr1 gene in kidney of zebrafish during fasting and refeeding. n = 8–10. F: feeding; S: starvation; R: refeeding. *: p < 0.05.

Oxidative stress in the kidneys of zebrafish during fasting and refeeding. (A) The content of MDA in kidney. (B) The change of ROS in kidney. (C) The content of NO in kidney. F: feeding; S: starvation; R: refeeding. n = 6–10. *: p < 0.05, **: p < 0.01; ***: p < 0.001.

The activity of enzymes in the antioxidant systems in kidneys of zebrafish during fasting and refeeding. (A) The activity of SOD in kidney. (B) The activity of GSH-Px in kidney. (C) The activity of CAT in kidney. F: feeding; S: starvation; R: refeeding. n = 6–10. *: p < 0.05, **: p < 0.01; ***: p < 0.001.

The parameters of the innate immune system in the kidneys of zebrafish during fasting and refeeding. (A) ALP activity in kidney of zebrafish during fasting and refeeding. (B) Lysozyme activity in kidney of zebrafish during fasting and refeeding. (C) The respiratory burst response of kidney in zebrafish after fasted and refed. (C1) The value of fluorescence/protein of kidney at different times. (C2) Fluorescence/protein values of kidney at 150 min. (C3) Normalization of the value of fluorescence/protein of kidney at 150 min. F: feeding; S: starvation; R: refeeding. n = 12. *: p < 0.05, **: p < 0.01; ***: p < 0.001.

The parameters of the innate immune system in the kidneys of zebrafish during fasting and refeeding. (A) ALP activity in kidney of zebrafish during fasting and refeeding. (B) Lysozyme activity in kidney of zebrafish during fasting and refeeding. (C) The respiratory burst response of kidney in zebrafish after fasted and refed. (C1) The value of fluorescence/protein of kidney at different times. (C2) Fluorescence/protein values of kidney at 150 min. (C3) Normalization of the value of fluorescence/protein of kidney at 150 min. F: feeding; S: starvation; R: refeeding. n = 12. *: p < 0.05, **: p < 0.01; ***: p < 0.001.

The mRNA relative expression of immune-related genes in the kidneys of zebrafish during fasting and refeeding. (A–F):il-1β, nfκb1, nfκb2, arg2, tgfb1a and tgfb1b. F: feeding; S: starvation; R: refeeding. n = 8–10. *: p < 0.05, **: p < 0.01; ***: p < 0.001.

The mRNA relative expression of immune-related genes in the kidneys of zebrafish during fasting and refeeding. (A–F):il-1β, nfκb1, nfκb2, arg2, tgfb1a and tgfb1b. F: feeding; S: starvation; R: refeeding. n = 8–10. *: p < 0.05, **: p < 0.01; ***: p < 0.001.

The mRNA relative expression of immune-related genes in the kidneys of zebrafish challenged with 5 μL of 20 μg/mL LPS after fasting and refeeding. (A–C) il-1β, mmp9 and nfκb1. F: feeding; S: starvation; R: refeeding. n = 8–12. *: p < 0.05, **: p < 0.01; ***: p < 0.001.