Relationships of liver weight, cholesterol, albumin and alpha 2-macroglobulin concentrations with ovarian function in swine

In two genetic swine models selected for diversity in ovulation rates (Whit e composite controls and ovulation rate selection line, n=131; 1/2 White co mposite: 1/2 Meishan crossbreds, n = 387), a positive relationship was esta blished with Liver weight and ovulation rate (P < 0.01). Serum changes of c holesterol, albumin and alpha 2-macroglobulin were monitored during various stages of the luteal phase and follicular phase (days 17 and 19 of the est rous cycle; 1/2 White composite: 1/2 Meishan gilts). Serum cholesterol conc entrations increased with liver weights (r = 0.19; P < 0.01) and corpora lu tea numbers (r = 0.14; P < 0.01). Albumin concentrations were negatively co rrelated with corpora luteal numbers (r = -0.3; P < 0.01) but had no relati onship with liver weight. Serum concentrations of alpha 2-macroglobulin wer e not related to liver weight or corpora lutea numbers. Circulating concent rations of cholesterol and alpha 2-macroglobulin increased with day of the estrous cycle (P < 0.01). Testosterone concentrations were inversely relate d to circulating cholesterol concentrations during the estrous cycle, but t estosterone concentrations on day 17 or 19 of the cycle were unrelated to c orpora lutea numbers. Concentrations of estrone on day 17 or 19 (as an inde x of follicles destined to ovulate) were also not related to numbers of cor pora lutea. Many interactions between liver and ovarian function involving metabolic and endocrine systems are plausible, but defined mechanisms resul ting in coordinate increases in liver weight and ovulation rates are presen tly unelucidated. Published by Elsevier Science Ltd. All rights reserved.