title: A study of the uterine protein variations during the estrous cycle in the cow: molecular weights determination.
abstract: This study was carried out to investigate molecular weights (MW) of the uterine protein content as the first step in their identification, and their variations during the estrous cycle as a part of the uterine adjustments for provision of an appropriate environment for physiological events in the bovine. Of the 24 pro-estrous, 21 estrous, 24 met-estrous and 46 diestrous uterine fluid samples prepared for our previous work, five samples in each phase were selected randomly and subjected to SDS-PAGE analysis in parallel with standard marker proteins to separate their protein content into fractions. By comparing these fractions with those of the standards, MWs of <14.4, 20, 30, 38, 40, 46, 67, 75, 85, 90, 160, 200, 210, 270 and 330 kiloDaltons (kDa) were calculated, respectively. Proteins with MWs of less than 14.4kDa [5.3 mg/ml (7.5% of total protein)] were observed only in met-estrus. Proteins with the MW of 20 kDa [14.0 mg/ml (19.4%)] were found only in diestrus. Proteins with MW of 30 kDa in met-estrus [20.6 mg/ml (28.9%)] and diestrus [4.5 mg/ml (6.3%)], and 38 kDa proteins were observed in a considerable amount in pro-estrus [41.4 mg/ml (44.5%)] and estrus [40.0 mg/ml (44.2%)]. Forty kiloDaltons proteins were observed only in diestrus [5.5 mg/ml (7.6%)], and 46 kDa proteins were observed only in met-estrus [5.3mg/ml (7.6%)]. Sixty seven, 75 and 330 kDa proteins were observed in all the phases of the cycle with different densities, the higher values recorded in diestrus, pro- and met-estrus, respectively. Proteins with MW of 85 kDa were observed in all the phases but diestrus [9.8 mg/ml (10.5%), 8.6 mg/ml (9.5%) and 7.3 mg/ml (10.2%) for pro-estrus, estrus and met-estrus, respectively], and proteins with MW of 90 kDa were observed in estrus [20.0mg/ml (22.1%)] and diestrus [3.3mg/ml (4.6%)]. Proteins of 160 kDa fraction were observed in pro-estrus [9.8 mg/ml (10.5%)] and met-estrus [10.7 mg/ml (15%)], 200 kDa proteins were observed only in diestrus [6.3mg/ml (8.7%)]; finally, 210 and 270 kDa proteins were observed only in estrus [3.4 mg/ml (3.8%) and 2.0 mg/ml (2.2%), respectively]. It was concluded that protein profile of the bovine uterine lumen changes during the estrous cycle, both in quality and quantity, which may be a part of uterine adaptation for the physiological events. Further identification of these proteins would give us a better insight into their role in the bovine reproduction.
authors: Department of Clinical Sciences, School of Veterinary Medicine, Urmia University, Urmia, Iran. m.alavi@mail.urmia.ac.ir
authors: S M
authors: SM
authors: Alavi-Shoushtari
authors: S
authors: S
authors: Asri-Rezai
authors: J
authors: J
authors: Abshenas
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D008970:Molecular Weight; D011506:Proteins / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism*
chemical_list: D011506:Proteins