Alan Goldfien

Sera From Preeclamptic Women Specifically Activate Human Umbilical Vein Endothelial Cells In Vitro: Morphological and Biochemical Evidence

ABSTRACT: Endothelial cell dysfunction could explain many of the pathophysiological changes observed in preeclampsia. Markers of endothelial cell activation including increased circulating Von Willebrand factor (VWF) and cellular fibronectin (cFN) antedate clinically evident disease. We have therefore proposed that alteration of endothelial cell function by circulating agent(s) produced by the placenta initiates the clinical syndrome. This hypothesis predicts that there are a factor(s) in the blood of women with preeclampsia that are capable of altering endothelial cell function. We and others have examined in vitro interactions of maternal serum and endothelial cells to test this hypothesis. Our initial report indicating increased release of [51Cr]chromate from human umbilical vein endothelial cells (HUVE) suggested a lethal, lytic effect of serum from preeclamptic women. However, more specific indicators of endothelial cell structure and function do not support such a nonspecific effect. The morphology of HUVE was minimally altered after exposure to sera of preeclamptic women, and the entry of propidium iodide entry into cells, a sensitive indicator of membrane integrity, also was not increased. These findings, in combination with the increased expression of mRNA for platelet‐derived growth factor (PDGF), suggest endothelial cell activation rather than cell death in response to sera from preeclamptic women. Comparison of the effects of endotoxin and sera from preeclamptic women also supports the specificity of this response. Whereas endotoxin strikingly increased VWF on the surface of HUVE and tissue factor activity in conditioned media while minimally increasing cFN, preeclamptic sera increased cFN but had no demonstrable effect on VWF or tissue factor activity. Thus, under the conditions of our in vitro assays, sera from preeclamptic women are not diffusely toxic but rather act selectively on specific activation pathways.

HIGHLY POTENT ADRENAL CORTICAL STEROIDS: STRUCTURE AND BIOLOGIC ACTIVITY

Excerpt Synthetic adrenal steroids possessing biologic activity greater than that of the naturally occurring secretory products of the adrenal cortex are of considerable theoretic importance and, i...

Human myometrial adrenergic receptors: Identification of the beta-adrenergic receptor by [3H] dihydroalprenolol binding

The radioactive beta-adrenergic antagonist [3H] dihydroalprenolol (DHA) binds to particulate preparations of human myometrium in a manner compatible with binding to the beta-adrenergic receptor. The binding of DHA is rapid (attaining equilibrium in 12 minutes), readily reversible (half time = 16 minutes), high affinity (KD = 0.50 nM), low capacity (Bmax = 70 fmoles/mg of protein), and stereoselective ([-]-propranolol is 100 times as potent as [+]-ipropranolol in inhibiting DHA binding). Adrenergic agonists competed for DHA binding sites in a manner compatible with beta-adrenergic interactions and mirrored beta 2 pharmacologic potencies: isoproterenol greater than epinephrine much greater than norepinephrine. Studies in which zinterol, a beta 2-adrenergic agonist, competed for DHA binding sites in human myometrial particulate indicated that at least 87% of the beta-adrenergic receptors present are beta 2-adrenergic receptors. Binding of DHA to human myometrial beta-adrenergic receptors provides a tool which may be used in the examination of gonadal hormonal modification of adrenergic response in human uterus as well as in the analysis of beta-adrenergic agents as potentially useful tocolytic agents.

Breast secretions in normal women

Abstract The incidence of breast secretions in a group of normal women was studied. No secretions were found in women who had never been pregnant, but were fairly common in those who had been gravid at one time. Usually the women were unaware of the presence of these secretions. The incidence of secretions in women taking oral contraceptives was less than in those not taking such medication. This investigation indicates that galactorrhea in an apparently normal nulligravida may be very significant, whereas a similar finding in a woman who has been pregnant in the past may have no clinical importance. It also suggests a lack of a causal relationship between oral contraceptives and galactorrhea.

Cocaine directly augments the a-adrenergic contractile response of the pregnant rabbit uterus***

Cocaine use in pregnancy is associated with a premature labor rate as high as 50%, but little is known about its effect on uterine contractility. To determine whether cocaine directly augments pregnant uterus contractility, uterine strips from 27-day pregnant New Zealand White rabbits (term, 31 days) were exposed to cocaine alone (30 mumol/L) or cocaine plus epinephrine (10(-9) to 10(-5) mol/L) or oxytocin (10(-10) to 10(-6) mol/L). Cocaine alone produced no contractions, but increased the epinephrine sensitivity by 51% and the maximal response by 33%. When beta-adrenoceptors were blocked with DL-propranolol (2 mumol/L), the contractile response to epinephrine was increased, and cocaines effect was blocked. In the presence of the stereoisomer D-propranolol (2 mumol/L) with no beta-adrenergic antagonist activity, the contractile response to epinephrine was unchanged, but the effect of cocaine was still blocked. We conclude that cocaine directly augments the alpha-adrenergic contractile response of the pregnant rabbit uterus by a mechanism that is blocked by the non-beta-adrenergic effects of propranolol.

PHARMACOLOGICAL STUDIES IN MAN OF 11-, 17-, AND 21-HYDROXY DERIVATIVES OF PROGESTERONE AND THEIR FLUORINATED ANALOGS

The oxygenated derivatives of progesterone include such highly active compounds as hydrocortisone and corticosterone, whose biological effects in experimental animals and in man have been extensively studied. Other compounds in this series, however, have been available in small amounts only, and studies of their activity in man are few.l In view of the remarkable potentiation of hydrocortisone by the substitution of a fluorine atom a t the 9a it seemed desirable to explore the metabolic activity of other 9a fluorinated steroids. Samples of the 9a fluorine derivatives of hydrocortisone, corticosterone, 1 1P-hydroxyprogesterone and 11, 17-dihydroxyprogesterone have been obtained (FIGURE 1) ; for purposes of comparison, the studies were extended to include the nontluorinated analogs and lla-hydroxyprogesterone. The intravenous route of administration was chosen as providing the most accurate basis for comparison of the small quantities of hormone available. Mefhods. These studies were carried out in the Metabolic Unit of the Peter Bent Brigham Hospital. Patients with proved Addison’s disease were allowed to come into balance on a constant diet before studies began. Sufficient time was allowed for them to return to equilibrium between the successive administration of the compounds being studied. The urinary sodium and potassium values were determined by flame photometry. The urinary glucose was estimated by the method of Renold and Froesch,’ in which the urinary reducing substances are compared before and after incubation with glucose oxidase. Other determinations were carried out as previously described? For intravenous administration the compounds were dissolved in ethanol and added to either 5 per cent dextrose in water or saline. On control days, similar infusions were given without addition of steroids. Obseroaliorzs. The effects of 25 mg. of progesterone, 1 la-hydroxyprogesterone, 1 lb-hydroxyprogesterone and 12 mg. of 9a-fluoro-ll@-hydroxyprogesterone on urinary sodium, potassium and glucose excretion were studied in a 20-year-old male with Addison’s disease. The steroids were dissolved in 20 ml. of ethanol, which wasadded to 250 cc. of 5 per cent dextrose and water. 3 , 4 ’ 5 p

Ovarian antibodies in disorders of ovarian function

Abstract Seventy-one women with various menstrual disorders but without evidence of known autoimmune disease were examined serologically for ovarian antibodies. Test serum, diluted 1:5, was reacted with sections of rabbit ovary and fluorescein isothiocyanate-labeled anti-human immunoglobulin. The tissue was then examined microscopically for fluorescence. Sixteen of the test sera reacted with the theca interna of ovarian follicles. None of the positive sera reacted with human adrenal and human and rabbit testis. Positive sera were found in subjects without ovarian failure. Indeed, two subjects with ovulatory cycles had positive sera. None of the sera of eight subjects with ovarian failure gave a positive response. The sera of two subjects were strongly positive at dilutions of 1:20 and 1:50, respectively. These subjects were carefully examined for other endocrinopathies but none was found. This study did not demonstrate a relationship between ovarian antibodies and antibodies to other steroid-producing tissues or to ovarian function.

DECREASED CONCENTRATION OF MYOCARDIAL α-ADRENOCEPTORS WITH INCREASING AGE IN FOETAL LAMBS

Using [3H]‐dihydroergocryptine, we identified myocardial α‐adrenoceptor binding sites in foetal lambs and demonstrated that the concentration of receptors decreased with increasing foetal age. The presence of the receptor in the foetus correlated with the presence of myocardial α‐adrenergic responsiveness. However, we found neither the α‐receptor binding site nor responsiveness to α‐adrenoceptor stimulation in the myocardium of adult sheep.

Possible Mechanism for the Antiarrhythmic Effect of Helium in Anesthetized Dogs

Breathing a mixture of 75 percent helium and 25 percent oxygen instead of 75 percent nitrogen and 25 percent oxygen reduced the occurrence of dangerous cardiac arrhythmias after ligation of the circumflex coronary artery in open-chest dogs anesthetized with pentobarbital. In dogs not subjected to circumflex ligation, the sensitivity of blood pressure, heart rate, and extrasystoles to epinephrine injected intravenously was not altered by the substitution of helium for nitrogen; however, helium did reduce the baseline heart rate and the concentration of endogenous plasma catecholamines. The antiarrhythmic effect of helium may thus be mediated by changes in sympathetic activity.

Progesterone prevents linkage of rabbit myometrial α2-adrenergic receptors to inhibition of adenylate cyclase

The uterine response to adrenergic stimulation is determined by the hormonal milieu. This response is particularly well characterized in the rabbit. In this species, as in humans, the response of the uterus to sympathetic stimulation is alpha-adrenergically mediated contraction with elevated circulating estrogen. However, with progesterone predominance, similar stimulation inhibits uterine contractions, a response mediated by beta-adrenergic receptors acting through their second message, cyclic adenosine monophosphate. We studied the mechanisms by which sex steroids regulate myometrial adrenergic responses. In this study, we questioned whether part of the effect of sex steroids could be explained by an alteration of the coupling of the alpha 2-adrenergic receptor to the inhibition of adenylate cyclase. We found that in the progesterone-treated rabbit, although alpha 2-receptors are present, they are not linked to inhibition of cyclic adenosine monophosphate synthesis. The net synthesis of cyclic adenosine monophosphage in response to endogenous catecholamines is determined by their activation of beta-adrenergic receptors to increase and alpha 2-receptors to decrease cyclic adenosine monophosphate formation. Thus the uncoupling of alpha 2-receptors contributes to increased intracellular cyclic adenosine monophosphate in myometrium of progesterone-treated animals consistent with the reported predominance of beta-adrenergic contractile responses in this setting.