Storage of Chinchilla lanigera semen at 4 degrees C for 24 or 72 h with two different cryoprotectants.

The objectives of this study were to: (a) test the functional activity of Chinchilla lanigera spermatozoa suspended in either glycerol or ethylene glycol, cooled to 4 degrees C, and stored for 24 or 72 h and (b) investigate, after these cooling periods, the effects of incubating sperm at 37 degrees C (for 4 h) upon sperm functional activity. The ejaculate was mixed with the cryoprotectant medium (at 1 M final concentration) and cooled to 4 degrees C. After warming, sperm motility, sperm viability, hypoosmotic swelling test results, and acrosomal integrity were significantly higher for samples containing ethylene glycol than for those in glycerol, stored for 24 or 72 h, and then assayed after 0 or 4 h incubation at 37 degrees C.

In vitro parthenogenesis of mouse oocytes under several experimental conditions.

Although the in vitro fertilisation index is a parameter commonly employed to investigate sperm functional activity, little attention has been given to the occurrence of parthenogenesis. The purpose of this study was to study at 6 h or 22 h incubation: (a) the cleavage-related events that occur in in vitro incubated mouse oocytes, in the absence (parthenogenesis) or presence of homologous spermatozoa; (b) the effect of mineral oil, commonly used in in vitro fertilisation assays; (c) the effect of piroxicam, a prostaglandin synthesis inhibitor, on the parthenogenetic rate; and (d) the influence on parthenogenesis of spontaneous loss of the cumulus oophorus coat during incubation. Under the experimental conditions employed, there was parthenogenetic activation and activation due to fertilisation.

Functional activity of mouse sperm was not affected by low doses of aspirin-like drugs.

To investigate some possible effects of low doses of nonsteroidal anti-inflammatory drugs upon functional activity of mouse sperm, the authors injected lysine acetyl salicylate (im 14.3 mg/kg day(-1), ibuprofen (ip 5.6 mg/kg day(-1)), or piroxicam (ip 0.

Activity of Chinchilla laniger spermatozoa collected by electroejaculation and cryopreserved.

Because reproductive studies and the application of assisted reproductive techniques are relevant issues for an endangered species such as Chinchila laniger, the availability of a source of viable spermatozoa becomes of utmost importance. In this paper, we evaluate several functional parameters (motility, viability, response to hypoosmotic swelling test and acrosomal integrity) of fresh or frozen-thawed spermatozoa. Electro-ejaculation trials (50-cyc/sec sinusoidal wave was applied for 5 of every 10 sec) were successful in all unanesthetized animals.

Influence of pentoxifylline on sperm membrane functional integrity.

In epididymal mouse spermatozoa, the effects of dibutyryl cyclic adenosine monophosphate 1 mmol/L (dbcAMP), pentoxifylline 5 mmol/L (PX), and/or mastoparan 50 mumol/L (MT) were evaluated for the following parameters: percentage of motile cells and response to hypoosmotic shock (HOS). The gametes were incubated during 80 min (A) or 200 min (B) in Tyrode's medium, and the drugs were added during the last 20 min. In A, dbcAMP + PX (61.

Functional activity of epididymal Chinchilla laniger spermatozoa cryopreserved in different extenders.

Chinchilla laniger is an endangered species and improved cryopreservation of spermatozoa would constitute a significant advance in the development of assisted reproductive techniques in this species. The functional activity of epididymal spermatozoa from adult males was studied immediately after extrusion and after 24 hours incubation, and the ability of five extenders to protect these gametes during cryopreservation was determined. A decrease in sperm motility, viability, acrosome intact cells and response to hypo-osmotic swelling test was detected 24 hours later.

Differential effects of pharmacologically generated reactive oxygen species upon functional activity of epididymal mouse spermatozoa.

Several studies indicate that reactive oxygen species (ROS) are involved in defective sperm function pathophysiology. In this study we attempted to determine differentially the effects of xanthine (0.12 mM) plus xanthine oxidase (0.

Trypanocidal effects of promethazine.

Promethazine is currently used for its antipsychotic and ansiolytic effects. It is a phenothiazine with anticalmodulin action, not toxic for human beings at therapeutic doses. The present results show that promethazine has trypanocidal effect on both epimastigote and trypomastigote stages of T.

Time-related changes in functional activity of mouse spermatozoa during in vitro or in vivo incubation.

The kinetics of functional modifications during in vivo or in vitro incubation was studied in spermatozoa from Albino Swiss mice, obtained from cauda epididymis (E) or from uterus (U) or oviduct (O) post copulation (p.c.).

[Profile of spermatic morphology in normospermic and dyspermic patients].

The evaluation of spermatic morphology is of importance due to its prognostic value in potential male fertility, both in natural and in assisted reproduction. In the present work, the morphologic profile of samples of semen from normal and dispermic patients was determined, in order to establish a correlation between structure and function. Samples were obtained from male partners of infertile couples who attended andrologic consultation.

Isometric developed tension and histopathology of myocardium of chagasic mice. II.

In a preceding paper we reported the evolution of chagasic cardiopathy in mice inoculated with low number of T. cruzi from 2 days to 75 days post-infection (p.i.

Disruption of mitochondrial function as the basis of the trypanocidal effect of trifluoperazine on Trypanosoma cruzi.

The tricyclic anti-calmodulin drug trifluoperazine (TFP) inhibited growth and motility of epimastigotes of Trypanosoma cruzi, at concentrations lower than 100 microM, and motility and infectivity of the bloodstream trypomastigote form at 200 microM. Electron microscopy of TFP-treated epimastigotes showed that the major effect was at the mitochondrial level, with gross swelling and disorganization. The oligomycin-sensitive, mitochondrial ATPase was completely inhibited by 20 microM TFP, and the same drug concentration caused a 60% decrease in intracellular ATP content.

Isometric developed tension and histopathology of myocardium of chagasic mice. I.

Cardiac disease is usually the most serious complication of human infection with Trypanosoma cruzi in our country. This report studies the evolution of the chagasic cardiopathy in mice inoculated with low number of parasites during acute and indeterminate stages in different aspects: contractility, histopathology and pharmacological response. From 2-45 days post infection (p.

Effects of helio-neon laser radiation upon cellular cycle in a plant model.

The scope of this study was to investigate possible relationships between He-Neon laser radiation and mitotic and phase indices in meristematic cells of Allium cepa L. bulbs. Our results indicate that mitotic index increased after irradiation depending this modification on the time exposure and the potency of the He-Neon beam.

Contractility and pharmacological reactivity of isolated vascular smooth muscle from diabetic rats.

Conflicting reports exist about the effects of diabetes on vascular function. In the present study we investigated (1) the influences of diverse stages of diabetes on mechanical activity and pharmacological reactivity of portal vein and tail ventral artery isolated from male rats 7, 21 or 30 days after alloxan injection (150-180 mg/kg) and (2) the effects of in vitro or in vivo insulin treatment. Various parameters were used to assess the diabetic state (serum glucose levels, body weight, percentage of glycosylated hemoglobin and glucosuria).

Effects of sodium nitroprusside on potassium induced contracture in isolated vascular smooth muscle.

The present study investigates the effects of Sodium Nitroprusside (SNP) on isometric developed tension (IDT) and tonic component of K+ induced contracture of rat portal vein. The availability of activator calcium for the contraction was modified by changing the ionic composition of the Krebs Ringer bicarbonate medium (KRB) or by using pharmacological agents such as nifedipine or KCl. In control conditions (KRB media) magnitude of IDT was 10.

[Demonstration of several functions of motoneurons using microcomputers].

In order to display some electrophysiological properties of the motoneurons, a special program for a microcomputer has been designed. The images in the monitor resemble those of an oscilloscope screen. The microelectrode penetration in the cell membrane, magnitude of the resting potential, inhibition and facilitation phenomena and the time-course of a spike potential are shown.

Pharmacological and contractile response of myocardium of Chagasic albino Swiss mice.

The isometric developed tension (IDT) and the pharmacological response of isolated myocardium from T. cruzi infected Albino Swiss mice in the acute and chronic Chagas' disease, were studied. The animals were infected with 7 X 10(4) trypomastigotes, form of T.

Release of prostaglandins E and F from rat uterine strips incubated in depolarizing and hyperpolarizing solutions.

The purpose of this study was investigate the effect of depolarizing (high K+, procaine 5 mM, high K+-Ca2+ free) or hyperpolarizing (K+ free) solutions on the generation and release of prostaglandins (PGs) E and F from the rat uterus. The output of PGs in the bathing solution was measured by bioassay. Results are expressed as ng/g dry weight/min.

Chronic Chagas' disease in the mouse: contractile response of the isolated myocardium.

The effects of different pharmacological agents on the isometric developed tension (IDT) of right ventricles isolated from chronic chagasic C3HS mice were studied. The IDT in ventricles of chagasic animals was lower than in ventricles of normal mice (P less than 0.01).

Modifications evoked by piretanide in the mechanical activity of cardiovascular tissues.

The effects of piretanide upon mechanical activity and pharmacological reactivity of vascular and myocardial tissues from normotensive rats were investigated. Magnitude of phasic contractions of isolated rat portal vein was diminished by the drug in a dose-related manner; contractile depression induced by piretanide (10(-4)M) was less in the presence of insulin (0.1 U/mL), glucose (22 mM) or pyruvate (5 mM).

Influence of the metabolic environment on oxygen uptake and isometric developed tension of isolated rat portal vein.

Oxygen uptake and isometric developed tension (IDT) of isolated rat portal vein were simultaneously measured after glucose removal, following the readmission of metabolic substrates and addition of 2-deoxy-D-glucose (2-DG) or insulin. In control conditions, basal O2 uptake was 0.128 +/- 0.

Effects of calcium antagonists on spontaneous and pharmacologically increased contractility of vascular smooth muscle.

Effects of calcium antagonists on spontaneous mechanical activity and pharmacological reactivity of isolated rat portal vein were investigated. Prenilamine (PREN) 2 X 10(-4) M, verapamil (VER) 2 X 10(-5) M and nifedipine (NIF) 3 X 10(-8) M abolished spontaneous phasic contractions. In veins incubated in calcium-free medium plus PREN, VER or NIF, readmission of calcium restored mechanical activity up to similar control values when [Ca2+]0 reached 4.