Photoprotective and Antimutagenic Activity of Agaricus subrufescens Basidiocarp Extracts.

The photoprotective and antimutagenic activity of opened and closed basidiocarps of Agaricus subrufescens (=A. blazei; =A. brasiliensis) obtained by different extraction methods were evaluated on Aspergillus nidulans conidia submitted to ultraviolet (UV) light. The aqueous extracts were obtained by three extraction methods: maceration, infusion, and decoction, at two different extraction times. The extracts of A. subrufescens did not present toxicity for A. nidulans conidia. A suspension of A. nidulans conidia was submitted to extracts before and after the exposure to UV light. All basidiocarp extracts, regardless of the extraction method or development stage, protected A. nidulans conidia against the damaging effects of the mutagenic agent. The antimutagenic and photoprotective activity was strengthened with extracts obtained by 168-h maceration, followed by 24-h maceration and 60-min infusion and, at last, by 30-min infusion. Although the extracts presented protector effect as well as recoverer effect to the action of UV light, the preventive effect was more evident. Differences in the biological activity in function of the different development stages were detected with greater antimutagenic and photoprotective activity for the opened basidiocarps. However, the extraction method is the most important factor to be considered when compared to the basidiocarp development stage to obtain better antimutagenic and photoprotective activity of A. subrufescens basidiocarps.

[A pulsed Doppler study of left atrial and ventricular inflow in 2 populations of normotensive and hypertensive subjects]. / Estudo Doppler pulsado do enchimento auricular e ventricular esquerdos em duas populações de normotensos e hipertensos.

OBJECTIVE: Comparative analysis of left atrial and left ventricle Doppler inflow patterns in patients with essential systemic mild to moderate hypertension and normal global left ventricular systolic function. PATIENTS: A group of out patients with the diagnosis of hypertension referred to the Echocardiographic Laboratory of Egas Moniz Hospital in Lisbon. SETTING: Echocardiographic Doppler prospective study. MATERIAL AND METHODS: We studied a group of 50 patients with the diagnosis of mild to moderate arterial hypertension (Group H), which was compared with a population of 50 normal subjects (Group N). In each case we analysed the pulsed Doppler flow of the right upper pulmonary vein and the diastolic inflow of the left ventricular cavity. We calculated the peak velocities and time velocity integrals of the systolic, diastolic and atrial contraction waves of the pulmonary venous flow and also the systo-diastolic velocity and time velocity integral ratios. In the transmitral Doppler flow analysis we evaluated the peak velocities and time velocity integrals of the early (E wave) and late (A wave) waves, and their time velocity and velocity ratio. We assessed also the isovolumic relaxation time and left ventricular mass index. RESULTS: In groups N and H the peak velocity of the pulmonary venous flow systolic wave was 0.53 +/- 0.15 cm/sec and 0.75 +/- 0.10 cm/sec (p = 0.01), diastolic wave was 0.50 +/- 0.10 cm/sec and 0.41 +/- 0.09 cm/sec (p = 0.03) and atrial contraction wave was 0.18 +/- 0.03 cm/sec and 0.35 +/- 0.08 (p = 0.001), with a systo-diastolic ratio of 1.06 +/- 0.10 and 1.83 +/- 0.10 (p < 0.001), respectively. In these two groups the time velocity integral of the pulmonary venous flow systolic wave was 14.4 +/- 2.6 cm and 17.8 +/- 1.8 cm (p = 0.001), the diastolic wave was 12.5 +/- 3.2 cm and 9.3 +/- 1.3 cm (p = 0.05) and the atrial contraction wave was 4.4 +/- 0.07 cm (p = 0.001), with a systo-diastolic ratio of 1.1 +/- 0.16 and 1.9 +/- 0.12 (p < 0.001), respectively. For the group H and considering the three subgroups, hypertensive patients without anatomical or functional alterations, with isolated diastolic dysfunction and with left ventricular hypertrophy associated to diastolic dysfunction, the velocity systo-diastolic ratio was 1.08 +/- 0.12, 1.57 +/- 0.08 (p < 0.01) and 2.4 +/- 0.08 (p < 0.01) and 2.4 +/- 0.08 (p < 0.001), the systo-diastolic time velocity integral ratio was 1.22 +/- 0.17, 1.72 +/- 0.13 (p < 0.01) and 2.4 +/- 0.15 (p < 0.001), the peak velocity of the atrial contraction wave was 0.28 +/- 0.07, 0.3 +/- 0.08 (p < 0.01) and 0.43 +/- 0.07 (p < 0.001) and its time velocity integral was 4.6 +/- 0.06 cm, 5.6 +/- 0.07 cm (p < 0.01) and 7.0 +/- 0.08 cm (p < 0.001). CONCLUSIONS: Pulsed Doppler study of pulmonary venous flow is significantly abnormal in patients with arterial hypertension. This abnormal pulmonary venous flow pattern has a close relationship with structural and functional alterations of the left ventricle. Combined analysis of the pulsed Doppler inflow at these two cardiac anatomical levels is fundamental to understand the pathophysiology of hypertensive heart disease.

The influence of testosterone on neuromuscular transmission in hormone sensitive mammalian skeletal muscles.

The influence of testosterone on neuromuscular transmission was studied in levator ani (LA) and extensor digitorum longus (EDL) muscles taken from normal rats, castrated rats, and castrated rats treated with testosterone. Thirty days after castration LA muscle weights were reduced by 60%, but the frequency and amplitude of the miniature end-plate potentials (mepps) were increased by 40% and 50%, respectively. The weights and mepp frequencies of the EDL muscles were not altered after castration, but the mepp amplitudes increased by 30%. The quantal content of the endplate potentials was not affected in either muscle. Administration of testosterone to the castrated rats prevented such changes in the LA muscles. The results indicate that castration of adult rats affects the spontaneous transmitter release in both muscles, but the changes are more pronounced in the levator ani, which is a target muscle for testosterone.

The triple effect induced by delta 9-tetrahydrocannabinol on the rat blood pressure.

The intravenous injection of delta 9-tetrahydrocannabinol (2-10 mg/kg) produced dose-related changes in the rat blood pressure. Three effects were detected: (1) an immediate and short-lasting hypotension related to bradycardia, blocked after atropine, vagotomy hexamethonium and pithing; (2) A rise in blood pressure 30 seconds after injection, insensitive to yohimbine, hexamethonium, pithing and reserpine treatment; (3) a slow and persistent hypotension, 5 min later, insensitive to atropine and vagotomy but inhibited by hexamethonium, pithing and reserpine treatment. It was concluded that intravenous injection of THC in rats may induce vagal stimulation and hypotension. This effect was reversed and followed by hypertension due to direct vasoconstriction not dependent on sympathetic activity. After this action a central decrease in sympathetic tonus led to a persistent hypotension an effect which is commonly reported for mammals.