Role of ACTH on the effect of medroxyprogesterone in brain stem serotonin.

A clinical study with 361 female rats was conducted to elucidate the mechanism whereby MPA (medroxyprogesterone acetate) lowers 5-HT/5-HIAA ratio in the brain area and the possible role of serotoniergic mechanisms. In addition, the participation of MAO (monoamino oxidase) system and the effects of some steroids were studied in order to establish a relationship between chemical structure and activity. The effects of the following steroids were studied: MPA (medroxyprogesterone acetate), melengestrol acetate, chlormadinone, pregnenolone, -methyl pregnenolone, DOCA, acetoxi-progesterone, and ACTH (synacthen). Effects of these substances on LTP (liver tryptophan pyrrolase) activity, total and free plasma and brain stem Trp (tryptophan), and the 5HT and 5HTAA content in brain stem are tabulated. Of all the substances, only MPA and melengestrol acetate significantly raised LTP activity and both also lowered 5-HT content of brain stem. The high levels of ACTH in the blood of the adrenalectomized rats, as in those under fasting conditions, antagonized MPA effects. To further test this seeming result, ACTH and ACTH-MPA were injected into another group of animals. The ACTH not only increased plasma corticosterone but also antagonized the effect of MPA on the 5-HT content of brain stem. The study did not identify a relationship between chemical structure of the steroids studied and effects observed.     

Stimulation of the mouse hepatic microsomal aniline p-hydroxylases by acetone and polyamines

The effects of acetone +/- spermine on the high (AH-I) and low (AH-II) affinity forms of aniline hydroxylases in the mouse hepatic microsomes were investigated under in vitro conditions. The addition of either acetone or spermine alone stimulated both AH-I and AH-II activities at low concentration while some decline in stimulation was noted at higher concentrations. In the presence of both the modifiers the observed monoxygenation rates were greater than those produced by any one enhancer alone for AH-I and more than additive for AH-II. The results suggest that the enhancement of aniline p-hydroxylation by the acetone and spermine in the mouse hepatic microsomes involves at least two separate and possibly interdependent mechanisms.     

Stimulation of adenylate cyclase activity in different areas of human brain by substance P.

Substance P and adenylate cyclase activity were measured in different areas of human brain. Highest levels of both substance P and basal adenylate cyclase activity were found in the hypothalmus, pineal gland and substantia nigra. Substance P was found to stimulate adeny-late cyclase activity in all brain areas but not in liver tissue.     

Stimulation of prolyl hydroxylase activity by bleomycin.

The activity of purified prolyl hydroxylase (proline, 2-oxoglutarate dioxygenase, EC 1. 14. 11. 2) was enhanced 3 approximately 8-fold at a low concentration of ferrous ion (1 X 10(-5 M) by addition of bleomycin, a glycopeptide antibiotic with antineoplastic activity and a side effect of producing pulmonary fibrosis. The maximum stimulation was attained at a concentration of 15 microgram/ml bleomycin (about 1 X 10(-5) M), which was approximately equimolar with the ferrous ion, one of the cofactors of this enzyme. Addition of bleomycin to the assay mixture resulted in a change of the optimal concentration of ferrous ion from 2 X 10(-3) M to 1 X 10(-5) M. Changing the order of addition of ferrous ion, enzyme and bleomycin in assay medium before incubation at 37 degrees C, the stimulatory activity was varied. Blemycin A2Cu++(Cu++-chelated bleomycin), which scarcely complexed with Fe++, had no enhancing effects on the enzymatic activity. We discuss the possible reasons as to why the activity of prolyl hydroxylase was enhanced by addition of bleomycin in the assay mixture.     

气相色谱法测定脂肪酶的活力

本文发展了一种以气相色谱检测脂肪酶活力的方法。以三丁酸甘油酯为底物,通过气相色谱对产物正丁酸进行定性定量分析。正丁酸在0.11～11.35 mmol·L^-1内线性关系良好, 回归方程为: y = 45 464x - 3 115.2, r = 0.996 8。反应时间仅需5 min,最适pH值和温度分别为7.5和32 ℃。低、中、高3个浓度正丁酸的回收率分别为90.3%,104.6%和89.4%;RSD分别为3.01%,4.50%和6.64%。通过实验测定出K_m =0.25 mmol·mL^-1,奥利司他的半数抑制浓度 (IC₅₀) 为0.048 5 mg·mL^-1。本方法具有反应体积小、操作简单、快速、灵敏等特点。     

An fMRI study of the effect of amphetamine on brain activity.

Functional magnetic resonance imaging was used to evaluate the effects of oral d-amphetamine on brain activation elicited by auditory and simple motor tasks in ten normal right-handed subjects. We measured the percent signal change and number of voxels activated by a tone discrimination task and a right hand finger-tapping task after 20 mg of d-amphetamine and after placebo. Compared to placebo, amphetamine significantly increased the number of activated voxels in the left and right primary auditory cortices during the tone discrimination task and increased the number of activated voxels in the ipsilateral primary sensorimotor cortex and right middle frontal area during the motor task. Although highly specific vascular effects of drug cannot be ruled out as an explanation, these results could also mean that amphetamine increases the neuronal activity associated with each of these two tasks.     

Role of polyamines in experience-dependent brain plasticity

Enriched experience increases brain growth, neuronal differentiation and learning abilities. Polyamines are modulators of growth and differentiation. We studied the effect of difluoromethylornithine (DFMO, an inhibitor of putrescine synthesis) on brain growth of rats exposed either to a complex or an impoverished environment. In both environmental conditions, DFMO decreased cortical putrescine by 50% and increased spermine by 13%; spermidine remained constant. Cortical RNA was not affected significantly by DFMO but DNA was decreased exclusively in rats exposed to the impoverished environment. Environmental complexity increased cortical weight, RNA and spermidine content. These differences were larger in DFMO-injected rats than in saline controls. Since stimulants such as amphetamines also enhance the environmental effects it was conceivable that DFMO might act as a stimulant. We have measured the effect of DFMO on rats' exploratory activity and found it decreased by the drug. Therefore the enhancing effect of DFMO cannot be explained by its behavioral activity. We propose that DFMO enhances the experience-dependent brain plasticity by facilitating differentiation of neurons.     

Enhancement of rat brain cytosolic monoamine oxidase activity by clorgyline. Comparison with (-)-deprenyl and MDL 72145

The presence of unsedimentable forms of monoamine oxidase (EC 1.4.3.4) in liver and brain homogenates has prompted fresh studies on the effects of inhibitors on this cytosolic monoamine oxidase. Clorglycine is a specific monoamine oxidase A inhibitor and (-)-deprenyl and MDL 72145 are specific monoamine oxidase B inhibitors. We investigated the effects of (-)-deprenyl, MDL 72145 and clorgyline on the purified enzyme from mitochondria and cytosolic monoamine oxidase along with high speed cytosol and 1% Triton X-100 treated mitochondrial preparations. Clorgyline enhanced the activity of the purified enzyme several-fold. (-)-Deprenyl and MDL 72145 also enhanced and inhibited the activity of cytosolic monoamine oxidase in a concentration-dependent manner.     

山楂饮片对胰脂肪酶活性的抑制作用研究

目的 探讨不同产地、不同品种的山楂样品对胰脂肪酶活性的抑制作用。方法 以对硝基苯基丁酸酯作为底物,在405 nm波长测定山楂饮片样品的水提物对胰脂肪酶体外活性。结果 各批次山楂样品对胰脂肪酶活性具有一定的抑制作用。结论 山楂可用于预防和治疗肥胖症;胰脂肪酶活性可作为山楂饮片等级划分的生物效应指标。     

The effect of perphenazine on the ACTH release induced by neurotropic stress

Summary In the present work the effect of both acute and chronic perphenazine treatment on the ACTH release induced by neurotropic stress has been studied. Adrenal ascorbic acid depletion was used as an indicator of the ACTH release. It was found that perphenazine was able in acute experimental conditions to inhibit exceedingly strong adrenal ascorbic acid depletion produced by neurotropic stress although in the perphenazine plus stress group the ascorbic acid content of the adrenals was significantly lower than in the intact controls. When perphenazine was administered daily during a longer period, the drug was no longer able on the ninth day of treatment to prevent the ACTH release and adaptation has thus occurred in this respect. Perphenazine was not able to prevent the adrenal ascorbic acid depletion induced by exogenous ACTH and pitressin. On the other hand it was observed that the perphenazine treatment in itself caused slight adrenal ascorbic acid depletion. The possible mechanisms of the action of perphenazine on the release of ACTH have been discussed in the light of previous results and those obtained in the present investigation.Aided by a grant from the Sigrid Jusélius Stiftelse.