P03-22 High glucose enhanced the inhibitory effect of mast cell chymase on the IGF-I-stimulated proliferation of rat aortic smooth muscle cells

Abstract

mals. A plasma progesterone concentration of 1ng/ml or more was taken as evidence of ovarian activity. Based on the resumption of ovarian activity, cows were classified as early cycling (EC; ≤ 45 days), late cycling (LC; >45 days), non-cycling (NC) during the period of study (10 weeks postpartum). An ANOVA (with repeated measures) procedure from SAS was used. Plasma concentration of IGF-I was higher (P < 0.001) in Sanga than in Friesian-Sanga cows (18.7±0.7 vs 14.8±0.7 ng/ml) from week 1 to 10 postpartum. Also, Sanga cows had higher (P < 0.001) plasma concentration of leptin than FriesianSanga cows (1.12±0.01 vs 0.96±0.01ng/ml). The concentration of IGF-I in plasma was higher (P < 0.05) in EC (21.9±1.51ng/ml) than in NC (17.1±1.10ng/ml) Sanga cows. Similarly plasma leptin concentration in the Sanga cows was higher (P< 0.001) in EC (1.23±0.02) than LC (1.10±0.03) or NC Sanga cows (1.06±0.01ng/ml). The EC Friesian-Sanga crossbred cows had higher (P< 0.001) plasma IGF-I concentration (20.51±1.03ng/ml) than LC (14.7±1.39ng/ml) or NC (12.60±0.64ng/ml) Friesian-Sanga cows. Also the EC Friesian-Sanga cows had higher (P < 0.01) plasma leptin concentrations than NC Friesian-Sanga cows (1.03±0.03 vs 0.92±0.02ng/ml). The results indicate that systemic IGF-I and leptin vary with breed type, being higher in Sanga than in Friesian-Sanga crossbred cows. Higher concentrations of these hormones are associated with early resumption of ovarian cyclicity in Sanga and Friesian-Sanga crossbred cows.