Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17174 (aspartate aminotransferase)
 14,872 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

For 21 postpartum dairy cows studied during the period of negative energy balance, the rate of muscle protein degradation, gluconeogenic changes, circulating large neutral AA, and plasma IGF-I were measured to investigate their possible association with the duration of anovulation and LH secretions. Cows that ovulated (n = 17) were energetically deficient at first ovulation but were approaching a balanced state. The dynamic changes in energy balance, but not the mean energy balance or the extent of BW loss, were correlated with days to first ovulation. Variations in energy balance were explained largely by variations in energy intake. Increased mobilization of body protein was indicated by higher concentrations of 3-methylhistidine during the first 3 wk postpartum and was not correlated with duration of postpartum anovulation. Plasma aspartate transaminase decreased significantly, and the proportion of Tyr to total large neutral AA significantly increased in the 12 d prior to first ovulation; both were correlated with LH secretion. Plasma IGF-I did not correlate with days to first ovulation, but correlated with LH pulse frequency. These findings indicate that decreased gluconeogenesis from AA is associated with duration of recovery and that Tyr may participate in metabolic signaling to the hypothalamus-hypophyseal axis controlling ovarian function in the postpartum dairy cow.
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PMID:Metabolic status and interval to first ovulation in postpartum dairy cows. 855 Sep

Metabolic hormones affect ovarian function in the cow. However, the relationship between metabolic factors and ovarian function is not clear in the postpartum primiparous cow because they are still growing. The aim of the present study was to investigate in detail the time-dependent profile of the metabolic hormones, metabolites, and milk yields of ovulatory and anovulatory primiparous cows during the first follicular wave postpartum. We used 16 primiparous Holstein cows and obtained blood samples for the profiles of metabolites (glucose; non-esterified fatty acid, NEFA; ketone body; total cholesterol; and aspartate aminotransferase), metabolic hormones (growth hormone, GH; insulin-like growth factor-I, IGF-1; and insulin), and progesterone every other day from 1 to 21 days postpartum. In addition, all ovaries were observed using ultrasound. Dairy milk yield was recorded during the experimental period. In all cows, the first follicular wave postpartum was observed and 6 of the cows ovulated. The plasma glucose (P<0.0001) and IGF-1 (P<0.001) concentrations were lower and the plasma NEFA (P<0.0001) and ketone bodies (P<0.0001) concentrations and daily milk yield (P<0.0001) were higher in the anovulatory cows compared to the ovulatory cows. However, the GH levels, which enhance lipolysis for milk production, insulin and other metabolites did not differ between the two groups. In conclusion, the present study suggests that anovulation of the dominant follicle during the first follicular wave postpartum in primiparous cows is induced by low IGF-1 levels that are similar to those of multiparous cows. In addition, anovulatory cows are likely to mobilize body fat stores for milk production more easily than ovulatory cows.
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PMID:Metabolic profiles in ovulatory and anovulatory primiparous dairy cows during the first follicular wave postpartum. 1704 86