Effect of Certain Drugs on Perfused Human Placenta IV

Effect of Certain Drugs on Perfused Human Placenta VIII

“…The results of this investigation indicate that the pressor response to angiotensin in the vasculature of the perfused human placenta is due principally to a direct stimulation of the vascular smooth muscle and, to a lesser degree, a stimulation of aadrenergic receptors present in these vessels (11). No release of either acetylcholine or norepinephrine by angiotensin, as a portion of its pressor action in these vessels, can be postulated from the results of this study.…”

“…doses of norepinephrine in a previous study with this preparation (11). after the pressor response to angiotensin subsided.…”

“…The apparatus used and the procedures employed in the preparation and perfusion of the placentas, in recording and maintaining the perfusion pressure, and in measuring the inflow and outflow volumes of the perfusate have been described in previous papers (10,11). In 38 successful placental preparations, each lasting 1 4 hr., a total of 106 studies was conducted.…”

The effect of Th 1165 a upon the reactivity of placental vessels in vitro

“…The smooth muscles of placental and umbilical vessels differ from the other smooth muscles by their lack of innervation (SPIVACK [14], BOYD and HAMILTON [2]), though the innervation of the placental vessels of subhuman primates has been proved (Fox and JACOBSON [8]). The nature of the reactivity of human placental vessels after the application of vasoactive substances allows to suppose the presence of both oc and receptors (MANCINI and GAÜ-TIERI [10]. According to recent concept of the receptors in the form of ensymatic Systems in cell membranes (WEIDINGER and WIEST [18]), the direct influence of Th 1165ä upon the beta receptors and upon the cell membrane can be supposed also in placental vessels.…”