dinoprost and 3-4-dihydroxyphenylglycol

Topics: Animals; Dinoprost; Drug Interactions; Epinephrine; Hemodynamics; Methoxyhydroxyphenylglycol; Microcirculation; Models, Biological; Prostaglandins F; Pyrrolidines; Vasoconstriction; Vasodilation

To investigate the interrelation among endogenous catecholamines, prolactin and prostaglandin F2 alpha, we measured the plasma levels of dihydroxyphenylalanine (DOPA), norepinephrine (NE), catecholamine metabolites (3,4-dihydroxyphenylacetic acid [DOPAC], 3,4-dihydroxyphenylethyleneglycol [DOPEG], cyclic 3',5'-adenosine-monophosphate (c-AMP), prostaglandin F2 alpha (PGF2 alpha) and prolactin (PRL) in 119 patients, before, during and after a normal labor and delivery, and in the early puerperium. In late pregnancy, DOPAC concentrations were significantly increased, and reached peak values before the onset of labor in the group who went into spontaneous labor. The DOPA, NE and DOPEG levels remained unchanged before labor. The plasma concentrations of NE, c-AMP and PGF2 alpha were significantly increased during labor. There was a positive correlation between plasma NE and c-AMP (r = 0.584, p less than 0.001), and between NE and PGF2 alpha (r = 0.401, p less than 0.001) during labor. In contrast, plasma PRL significantly decreased during labor and immediately after delivery. There was a statistically significant inverse relationship between PRL and NE (r = -0.392, p less than 0.001) and between PRL and PGF2 alpha (r = -0.523, p less than 0.001) during labor, but there was no statistical correlation among PRL, DOPA and DOPAC. In conclusion, these data suggest that the dopaminergic activity in the maternal circulation increases before the onset of labor, and the PRL release from the maternal pituitary gland during labor is probably not controlled primarily by dopaminergic neurons and may be suppressed by other mechanisms, such as the stress of labor and/or the influence of PGF2 alpha.

Topics: 3,4-Dihydroxyphenylacetic Acid; Adult; Catecholamines; Cyclic AMP; Dinoprost; Female; Humans; Labor, Obstetric; Methoxyhydroxyphenylglycol; Postpartum Period; Pregnancy; Pregnancy Trimester, Third; Prolactin

The effects of tertatolol, a new and powerful beta adrenoceptor blocking drug, on post- and prejunctional beta receptors were investigated; canine vascular tissues (saphenous veins, coronary arteries and splenic arteries) and guinea-pig trachea and atria were used. At concentrations below 10(-5) M, tertatolol did not alter basal tension or contractile responses to electrical stimulation, norepinephrine, K+ or prostaglandin F2 alpha; at doses at or above 10(-5) M the drug-evoked contractions which were reduced by phentolamine and were absent in denervated veins. Tertatolol at 10(-5) M and 3 X 10(-5) M augmented the basal efflux of [3H] norepinephrine in saphenous veins labeled with the 3H-transmitter. In veins, 10(-5) M of tertatolol depressed the contractions caused by electrical stimulation without affecting those to exogenous norepinephrine; this concentration of the drug also inhibited the stimulation-induced overflow of [3H]norepinephrine. The major part of the present study was designed to test the beta receptor blocking properties of tertatolol and to compare its effects with those of propranolol. Tertatolol inhibited, in a concentration-dependent manner, the relaxations caused by isoproterenol in saphenous veins, splenic arteries and coronary arteries and the relaxations evoked by norepinephrine and epinephrine in coronary arteries; the potency of tertatolol was higher than that of propranolol. In trachea and right atria of the guinea-pig, tertatolol inhibited, in a concentration-dependent manner, the dose-response curves to isoproterenol; the relative potency of tertatolol was higher than that of propranolol. In dog saphenous veins, previously incubated with [3H]norepinephrine, tertatolol (10(-7)M) blocked the increased stimulation-evoked overflow of the 3H-transmitter induced by isoproterenol.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adrenergic beta-Antagonists; Animals; Blood Vessels; Dinoprost; Dogs; Dose-Response Relationship, Drug; Epinephrine; Guinea Pigs; Heart; In Vitro Techniques; Isoproterenol; Methoxyhydroxyphenylglycol; Norepinephrine; Potassium; Propanolamines; Prostaglandins F; Receptors, Adrenergic, beta; Thiophenes; Trachea