Phosphate metabolism and foetal growth in the rat II. Net transfer of31P and32P inorganic phosphate from the maternal plasma to the normal foetus

1982 ◽  
Vol 90 (5) ◽  
pp. 337-346
Author(s):  
E. C. Van Bogaert ◽  
Christiane O. Gueuning ◽  
G. L. A. Graff
2017 ◽  
Vol 133 ◽  
pp. 74-85 ◽  
Author(s):  
Fernando Santos-Beneit ◽  
María Ordóñez-Robles ◽  
Juan F. Martín

1979 ◽  
Vol 83 (1) ◽  
pp. 119-127 ◽  
Author(s):  
J. FALCONER ◽  
J. M. FORBES ◽  
I. C. HART ◽  
J. S. ROBINSON ◽  
G. D. THORBURN

SUMMARY Plasma samples from pregnant ewes and their foetuses during the last quarter of gestation were assayed for somatomedin-like activity (SLA) using the porcine costal cartilage assay. In maternal plasma, the mean potency (compared with pooled serum from six sheep) was 0·84 ± 0·05 (s.e.m.) units/ml (n = 15). Somatomedin-like activity in the plasma of five control foetuses (0·91 ± 0·1 units/ml) was similar to the maternal levels and did not change with gestational age. After foetal hypophysectomy the SLA in foetal plasma (0·37 ± 0·05 units/ ml, n = 4) was significantly less than in control animals. In two nephrectomized foetuses, the mean SLA in plasma (0·08 and 0·51 units/ml respectively) was less than in control animals. Retardation of intra-uterine foetal growth was induced by removal of endometrial caruncles before pregnancy in four sheep. The SLA in plasma from these foetuses was 0·38 ± 0·05 units/ml (P< 0·01 v. control animals). The results suggest that SLA in the foetus may be important in the regulation of foetal growth, but they also indicate that factors other than growth hormone may be important in the control of SLA in foetal plasma.


1961 ◽  
Vol 39 (12) ◽  
pp. 1879-1894
Author(s):  
Rhoda Blostein ◽  
David Rubinstein ◽  
Orville F. Denstedt

The rate of passage of cations across the red cell membrane, in the direction of the respective ionic gradients, in blood preserved with glucose at 4 °C, is not diminished upon the addition of inosine, notwithstanding the induced formation of substantial amounts of phosphate esters, including ATP, in the cells. The movement of cations, however, is retarded on the addition of glucose or inorganic phosphate, and on increase in the concentration of hydrogen ions. It would appear, therefore, that the movement of cations across the membrane, at 4 °C, is influenced little, if at all, by the metabolic activity of the cell.When the temperature of the preserved blood is returned to 37° the rate of movement of cations across the cell membrane against their respective gradients is greatest in cells which had either been preserved or have been incubated with inosine even if the remainder of the inosine has been removed. Inosine is more effective than glucose in bringing about the restoration of cation composition in preserved red cells at 37°. The degree of restoration is greater in the presence of glucose than in its absence. Arsenate inhibits the transport of cations against the gradients. Evidence is given that the capacity of the cells to restore the cation distribution at 37 °C is determined largely by the concentration of the phosphate ester intermediates.


2000 ◽  
Vol 70 (2) ◽  
pp. 363-369 ◽  
Author(s):  
S.T. Morris ◽  
S.N. McCutcheon ◽  
D.K. Revell

AbstractThis study compared the effect on foetal growth of shearing ewes in very early pregnancy (day 50) with the effect of shearing later in pregnancy (day 70 or 100). One hundred and sixty ewes were allocated at day 49 of pregnancy to four ‘time of shearing’ treatments — pregnancy day 50 (P50), P70, P100 (no. = 45 ewes per treatment) and unshorn (shearing of this group occurred 43 days after weaning) (no. = 25); two methods of shearing (by standard comb and cover comb); and two levels (1 or 2) of pregnancy/rearing rank. All ewes had been mated over a 28-day period and grazed pasture throughout the trial. The mid point of lambing was 27 August 1996. Live weights of ewes (corrected for fleece weight) were not influenced by shearing time at any stage except at day 45 of lactation when ewes shorn at P50, P70 or P100 were about 3⋅0 kg lighter than unshorn ewes. Shearing method had no effect on ewe live weight. Time of shearing and shearing method had no effect on ewe greasy fleece production or wool tensile strength. Shearing significantly (P < 0⋅05) influenced the birth weight of single- (by 0⋅7 to 0⋅8 kg) but not twin-born lambs. Maternal plasma triiodothyronine concentration increased proportionately by 0⋅47 to 0⋅85 (P < 0⋅05) and lasted for at least 20 days in response to shearing irrespective of time of shearing. No difference in plasma insulin concentration was detected between shearing groups but plasma glucose concentration proportionately increased by 0⋅06 to 0⋅16 (P < 0⋅05) for 10 to 20 days after shearing. These results indicate that shearing between day 50 and 100 of pregnancy can increase lamb birth weights and that the response is associated with an increase in thyroid hormone concentrations in the maternal circulation.


1991 ◽  
Vol 124 (6) ◽  
pp. 679-684 ◽  
Author(s):  
Heide S. Cross ◽  
Meinrad Peterlik

Abstract. Embryonic chick jejunum maintained in organ-culture exhibits a characteristic stage-specific pattern of responses to calcitriol and T3. Whereas induction of luminal Na+/inorganic phosphate and Na+/D-glucose transport by calcitriol was only possible at an advanced state of differentiation prior to hatching on day 20, the sterol induced cellular calcium transport with high efficiency even in undifferentiated enterocytes in day 15 embryonic intestine. T3 had no effect at all on calcium transport, but induced Na+/inorganic phosphate transport at all stages of epithelial maturation. In contrast, Na+/D-glucose transport was effectively induced by T3 only in relatively immature intestinal epithelium. T3, at a medium concentration of 10−8 mol/l, in a permissive fashion potentiated the effects of calcitriol (10−10−10−7 mol/l) on calcium transport as well as on Na+/inorganic phosphate and Na+/D-glucose transfer. Thereby, T3 facilitated induction of transport activities by calcitriol against differentiation-related restraints. By facilitating the expression of genomic actions of calcitriol, T3 may thus play an important role in the regulation of calcium and phosphate metabolism.


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