ABSTRACT
The course of inorganic-phosphate (Pi) concentrations in blood plasma and serum were determined in lactating ruminants when P intake was changed abruptly from adequate, during a control period, to very low in a period of P depletion, and back to adequate during a period of P repletion. In each of three trials, four or three goats and, in one trial, four cows were used. In addition, the course of P concentration in the rumen fluid of three fistulated goats was studied. Pi concentrations in plasma or serum started to fall immediately with changing P intake from adequate to low, reaching a minimum plateau of less than 0.25 mM in three trials and 0.4 mM in one trial. Correspondingly, concentrations rose instantly with return of P intake to adequate, overshooting the range observed in goats during the control period and then returning to normal. P concentrations in particle-free rumen fluid declined from about 30 mM in the control period to 5.7 mM during P depletion and returned to 30 mM during P repletion, paralleling the respective course of Pi in blood plasma.
Subject(s)
Cattle/metabolism , Goats/metabolism , Lactation/metabolism , Phosphates/administration & dosage , Rumen/metabolism , Administration, Oral , Animals , Female , Phosphates/blood , Phosphates/metabolismABSTRACT
By the pulsed doppler method the arterial uterine blood velocity was studied in 19 patients with contractions before and during labour. It is shown, that uterine contractions reduce blood velocity significantly. Normally there is a low resistance in uterine arteries, so that the diastolic flow is nearly as high as the systolic flow. In uterine contractions the vascular resistance increases. Systolic flow is reduced slightly and diastolic flow severely or completely. But a complete zero-flow couldn't observed in any studied uterine contraction.
