Morphological and pharmacological effects of reserpine, given alone or after iproniazid, on the catechol amines of the adrenal glands of the rat.
(9/50)
Adrenomedullary cells, after fixation with OsO(4), are filled with well formed granules which are considered to represent their catechol amine content. The submicroscopic appearance of these cells was studied in reserpine-treated rats during the late phase of catechol amine depletion and during the period of its restoration. At 3 days after the beginning of reserpine treatment, the granules appeared to be emptied of their content and small vesicles containing scattered, dense deposits of, presumably, catechol amines began to be seen. At 9 days after the beginning of treatment, these deposits had already become granules and the cells had attained a completely normal appearance. The submicroscopic structure of the adrenomedullary cells of rats pretreated with iproniazid (before reserpine), in which a complete inhibition of monoamine oxidase activity had thus been obtained, was similar to that seen in non-treated animals. In numerous cases, however, some characteristic features were noted: the sacs which usually contained a dense granule of catechol amines appeared swollen and many fine granules could be seen around them; the latter were dispersed in a way suggesting that they may represent a partial breakdown of the large granules which, under the inhibitory action of iproniazid, do not release the catechol amines contained within them. (+info)
THE 5-HYDROXYTRYPTAMINE CONTENT OF THE PLACENTA AND FOETUS DURING PREGNANCY IN MICE.
(10/50)
5-Hydroxytryptamine (5HT) levels were measured in blood and tissues from pregnant mice. Blood levels remained constant during pregnancy and were the same as those in nonpregnant female mice. Placental levels of 5HT increased throughout pregnancy as did the foetal levels. The maternal blood volume of the placenta also increased with advancing gestation. 5HT levels were measured after treatment of the mother with 5HT, and the critical placental level of 5HT observed at about the time of death of the foetus was determined. The levels of 5HT in the placenta and foetus after treatment of the mother with several monoamine oxidase inhibitors were measured, and found to show no significant increase above the normal levels in these tissues. Treatment with cyproheptadine, a 5HT antagonist, did not delay parturition. (+info)
EFFECTS OF CHLORPROMAZINE AND BROMOLYSERGIC ACID DIETHYLAMIDE ON GASTRIC SECRETION OF ACID INDUCED BY HISTAMINE IN RATS.
(11/50)
In anaesthetized rats in which the lumen of the stomach was perfused with 0.001 to 0.00025 N-sodium hydroxide solution and the pH of effluent fluid was recorded continuously, intravenous administration of chlorpromazine caused transient inhibition of acid secretion. After acid secretion had returned to the control level the responses to histamine were greater than those before chlorpromazine was given. Aminoguanidine, iproniazid and bromolysergic acid diethylamide also potentiated the effect of histamine on acid secretion but the initial inhibition was absent. Indirect evidence from experiments in which mixtures of aminoguanidine with chlorpromazine or bromolysergic acid diethylamide and of iproniazid with chlorpromazine or bromolysergic acid diethylamide were given, suggests that chlorpromazine and bromolysergic acid diethylamide enhance responses to histamine by inhibition of imidazole-N-methyl transferase. (+info)
INHIBITORS OF HISTAMINE CATABOLISM AND THE ACTION OF GASTRIN IN THE RAT.
(12/50)
A method is described for the partial purification of hog's antral gastrin by gel filtration and ion-exchange chromatography. Gastrin was assayed by its effect on the pH of the effluent fluid from the perfused lumen of the stomach of the anaesthetized rat. The latency of the response to gastrin given intravenously was shorter than the latency to a similar dose of histamine. The response to gastrin injected into the arterial circulation of the stomach appeared sooner than the response to gastrin injected intravenously. Iproniazid and aminoguanidine potentiated responses to gastrin. Incubation in vitro with monamine oxidase or diamine oxidase did not inactivate gastrin. Chlorpromazine and bromolysergic acid diethylamide, in doses which enhance the effects of histamine on acid gastric secretion, did not affect responses to gastrin. (+info)
THE CONVERSION OF PYRIDOXINE PHOSPHATE INTO PYRIDOXAL PHOSPHATE IN ESCHERICHIA COLI.
(13/50)
1. Evidence is presented for the presence of pyridoxine phosphate oxidase in aqueous extracts of Escherichia coli. Some comparison is made with pyridoxamine phosphate oxidase. 2. Isoniazid and iproniazid were found to combine with pyridoxal phosphate, but isoniazid did not combine with either pyridoxamine phosphate or pyridoxine phosphate. Both oxidase activities were somewhat inhibited by benzylamine and putrescine, but not by phenethylamine or cadaverine. 3. The significance of pyridoxine phosphate oxidase in cell metabolism is discussed. (+info)
The effect of iproniazid and imipramine on the blood platelet 5-hydroxytrptamine level in man.
(14/50)
Observations are reported on the blood platelet 5-hydroxytryptamine content of six patients receiving imipramine, N-(gamma-dimethylaminopropyl)-iminodibenzyl hydrochloride. The response was a fall to a level of one-sixth of the original in three weeks, with little change thereafter. This is in sharp contrast to the action of iproniazid which caused a rise of some 200% in the blood platelet 5-hydroxytryptamine level over the same period. Imipramine in a concentration of 1 mg./ml. had no inhibitory action on 5-hydroxytryptophan decarboxylase; 8.0 mug./ml. of imipramine suppressed two-thirds of the in vitro uptake of 5-hydroxytryptamine (2.5 mug./ml.) by normal human platelets. (+info)
Clinical observations on iproniazid in idiots with epilepsy.
(15/50)
In contradistinction to the observation made before that iproniazid has a potentiating effect on certain amines in guinea pigs, human studies have shown that this effect has very little clinical importance, when both the amines and the amine oxidase inhibitor are given in the usual therapeutic doses. However, neither in man nor in the guinea pig pretreatment with iproniazid showed a potentiating effect on amines which are not substrates of monoamine oxidase (ephedrine and amphetamine). Patients with epilepsy and allergic disease may receive iproniazid. (+info)
Antiphlogistic activity of iproniazid.
(16/50)
Iproniazid was found to inhibit formalin-induced oedema of the foot, dextran-induced oedema and cotton-pellet-induced granulomatous tissue in the rat. The presence of the adrenals was essential for the antiphlogistic activity. The antiphlogistic action was not accompanied by any antipyretic effect. Inhibition of formalin-induced oedema was also observed with phenylbutazone and with salicylamide. (+info)