THE IMMEDIATE RESPONSE OF THE PLASMA PROLACTIN LEVEL TO OESTROGEN INFUSIONS IN DAIRY COWS

1972 ◽  
Vol 69 (1) ◽  
pp. 47-52 ◽  
Author(s):  
D. Schams ◽  
H. Karg
Keyword(s):  
Blood Plasma ◽  
Dairy Cows ◽  
Prolactin Level ◽  
Fold Increase ◽  
Plasma Prolactin ◽  
Plasma Samples ◽  
Subsequent Increase ◽  
Plasma Prolactin Level ◽  
Immediate Response ◽  
In Blood Plasma

ABSTRACT Prolactin in blood plasma samples obtained from cows was determined by radioimmunoassay. During infusion of 2 mg or 4 mg 17β-oestradiol/hour there was a depression of the prolactin level, which seemed to be pronounced during infusions of 6 or 12 mg 17β-oestradiol/3 hours. In the experiments in which 2-6 mg 17β-oestradiol were administered a 2-5 fold increase in the plasma prolactin concentrations occurred after the infusions were completed. In the experiment with 12 mg 17β-oestradiol the depression was sustained for 3 hours after infusion; the subsequent increase the next few hours was comparatively small.

THE IMMEDIATE RESPONSE OF THE PLASMA PROLACTIN LEVEL TO OESTROGEN AND PROGESTERONE INFUSIONS IN BULLS

1974 ◽  
Vol 76 (2) ◽  
pp. 242-247 ◽  
Author(s):  
D. Schams ◽  
V. Reinhardt ◽  
H. Karg
Keyword(s):  
Prolactin Level ◽  
Plasma Prolactin ◽  
Subsequent Increase ◽  
Plasma Prolactin Level ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Immediate Response

ABSTRACT The technique of radioimmunoassay was used to determine prolactin concentration in plasma taken from bulls during and after infusions of oestradiol-17β and progesterone. During the infusion of oestradiol-17β (0.5, 1 and 2 mg) for 1 h the concentration of prolactin in the plasma fell, but showed an immediate increase of up to 6-fold after the infusion was completed. A dose-dependent increase (up to 20-fold) in prolactin concentration was observed after the infusion for 1 h of 5, 10, 40 and 80 mg progesterone. In those experiments in which 40 and 80 mg were administered the depression normally seen during the infusion was sustained for 2–3 h and the subsequent increase during the next few hours was comparatively small.

scholarly journals Effect of pregnancy and stage of lactation on energy processes in isolated blood cells of dairy cows

2017 ◽  
Vol 61 (2) ◽  
pp. 211-215
Author(s):  
Bogdan Dębski ◽  
Tadeusz Nowicki ◽  
Wojciech Zalewski ◽  
Agnieszka Bartoszewicz ◽  
Jan Twardoń
Keyword(s):  
Blood Plasma ◽  
Dairy Cows ◽  
Blood Cells ◽  
Transition Period ◽  
Energy State ◽  
Animal Health ◽  
Fatty Tissue ◽  
Strong Positive Correlation ◽  
Simple Method ◽  
In Blood Plasma

AbstractIntroduction: The transition period is the most challenging time for dairy cattle, which is characterised not only by negative energy balance but also by fatty tissue mobilisation.Material and Methods: The efficiency of energy pathways, β-oxidation in WBC and glycolysis in RBC (based on deoxyglucose transmembrane transport) were estimated. Insulin in blood plasma was determined using ELISA.Results: After calving and up to one month after delivery, a significant drop in blood plasma level was noticed, simultaneously with a rise in β-oxidation from 18.93 ±3.64 to 30.32 ±5.28 pmol/min/mg protein in WBC. A strong negative correlation between these two indices (r = −0.68) was found. During the period of transition to lactation an increase in glucose cross-membrane transportation from 41.44 ±4.92 to 50.49 ±6.41 μmol/h/g Hb was observed. A strong positive correlation between glucose transportation in RBC and β-oxidation in WBC (r = 0.71) was noticed. These data are in agreement with results of studies on dairy cows using liver slices from dairy cows in late pregnancy and different stages of lactation, in which changes in gene expression were analysed.Conclusion: It seems that measuring fatty acids oxidation and glycolysis using isolated blood cells may be an adequate and relatively simple method for energy state analysis to estimate the state of dairy cow metabolism and animal health.

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