Effects of acute cold exposure on rectal temperature, blood glucose and plasma free fatty acids in alloxan-diabetic rats

These experiments were carried out to study the effects of acute cold exposure (0-2°C/4 hr) on rectal temperature, blood glucose and plasma free fatty acids (FFA) in alloxan-diabetic rats. Male Wistar rats weighing 170-190 g were used and diabetes was induced by i.v. alloxan injection (40 mg/kg body wt). Cold exposure produced severe hypothermia in diabetic rats. After 4 hr of cold, blood glucose of diabetic rats was reduced from 296±16 to 86t±12 mg/dl (P<0.01), and FFA increased slightly, but was not statistically different (P>0.05) from the initial value. As expected, interscapular brown adipose tissue (IBAT) and retroperitoneal and epididymal white adipose tissues were significantly lower in diabetic than in control rats. Cold exposure reduced total IBAT lipids in control but not in diabetic animals. The results of this experiment suggest that diabetic rats were unable to maintain body temperature in the cold, probably because of a failure to generate an adequate amount of heat by nonshivering thermogenesis in brown adipose tissue.

Fine structure of the ductuli efferentes of the hamster (Mesocricetus auratus).

Structurally the ductuli efferentes of the hamster showed 2 distinct segments, a testicular and an epididymal. Both of these segments were lined by a pseudostratified epithelium, which showed basically non-ciliated and ciliated cells. In the testicular segment a 3rd type of oval dark cells was observed. The ultrastructural characteristics of these cells were presented and discussed in this report.

Efeitos do tratamento oral com sulfato de vanadila em ratos diabeticos jovens

This work intends to evaluate the effects of oral vanadyl treatment (VOSO 4, 1 mg/mL) in young streptozotocin-diabetic rats during 19 and 29 days. In several times of treatment the rats were monitored to determine body weight, food and water intakes, glycemia, and the urinary excretion of glucose and urea. The animals were killed in the 19(th) and 29(th) days, and the glycemia level was determined again, as well as the weight of pancreas, muscles (Soleus and Extensor digitorum longus - EDL) and adipose tissues (epididymal and retroperitoneal). The results showed that the treatment of young diabetic rats with VOSO 4 promotes the reduction of hyperglycemia (p < 0.01), food (p < 0.01) and water intakes (p < 0.05) and body weight (p < 0.05). Neither the tissues and pancreas weights nor the urinary urea level of the treatment group varied in comparison to the control group. In conclusion, the vanadyl treatment in the studied period is able to reduce the main metabolic alterations often found in diabetes. These data are very useful and important for the future experiments to verify the effects of vanadyl sulfate on muscle protein metabolism in diabetic rats.

Detection of leptospires in bovine semen by polymerase chain reaction

Objective: In view of the considerable importance of venereal transmission of bovine leptospirosis, the objective of the present study was to compare the polymerase chain reaction (PCR), culture/isolation and serology to detect leptospire infection in bovine semen. Design: Blood for serologic examination and semen for bacterial culture and PCR were collected from 20 bulls at artificial insemination centres in Brazil. Each animal was sampled twice for serology. Result: Forty-five percent (9/20) of the serum samples collected showed agglutinin titers to serovar hardjo in the first sample and 25% (5/20) had agglutinin titers to serovar hardjo in the second sample. Eighty percent (16/20) of semen samples were positive by PCR. Leptospires could not be isolated from any of the semen samples examined. Conclusion: Polymerase chain reaction can be a method of great potential for the detection of leptospires at artificial insemination centres.

Ultrastructure of Sorubim lima (Teleostei, Siluriformes, Pimelodidae) spermiogenesis

The spermiogenesis and the spermatozoon ultrastructure of Sorubim lima were studied. Our observations showed that early spermatids are round-shaped cells, have spherical nucleus with diffuse chromatin, small quantity of mitochondria and large amount of vesicles in the cytoplasm. During the differentiation process in the nucleus, chromatin compacts in a progressive and homogeneous way, and the flagellum is formed. In the cytoplasm the vesicles, that have double membranes, aggregate and fuse on the plasma membrane. The spermatozoa of 5. lima have no acrosome and show spherical nucleus with homogeneous and highly compacted chromatin, intermediary piece with mitochondria and double wall vesicles contiguous to the plasma membrane, as well as a flagellum formed by a basic axoneme (9 + 2).

Testicular ultrastructure and morphology of the seminal pathway in Prochilodus scrofa

The seminiferous tubules of Prochilodus scrofa present a coiled morphological arrangement with intertubular anastomoses and unrestricted spermatogonial distribution. The structural pattern of the seminiferous tubules is cystic, with cysts formed by cytoplasmic prolongations of Sertoli cells. Inside the cysts are observed different types of germ cells. The seminiferous tubules open individually on the ventral surface of the main testicular duct present in each testis. Each main testicular duct prolongs as a spermatic duct, fusing with the spermatic duct of the opposite side to form the common spermatic duct which opens into the urogenital papilla. The mature sperm cysts break and extravasate their content into the lumen of the seminiferous tubules from which the seminal fluid and the spermatozoa penetrate the main testicular duct, the spermatic duct and the common spermatic duct for semen ejaculation.

Evaluation of plasma membrane integrity of frozen-thawed goat spermatozoa with or without seminal plasma

The aim of the present work was to evaluate plasma membrane integrity, motility, vigor and morphology of fresh and frozen goat spermatozoa with or without seminal plasma. Semen samples were diluted in Tris solution, before and after thawing, with a combination of carboxifluorescein diacetate and propidium iodide. The results showed differences (P < 0.01) for motility and minor defects in the presence or absence of seminal plasma, for both fresh and frozen samples. Periods of collection had a significant effect on motility, probably due to changes in the photoperiod. Plasma membrane integrity was significantly reduced by the freezing process, whether seminal plasma was present or absent. In conclusion, removal of seminal plasma decreased motility and vigor rates in frozen samples. The photoperiod probably decreased the testosterone level, contributing negatively to the high percentage of sperm abnormalities, mainly damaged membranes. The use of fluorescent probes allowed a better estimation of the percentage of functional cells, instead of only estimating the percentage of motile cells or morphology defects. © 2001 Elsevier Science B.V. All rights reserved.

Reproductive changes in male rats treated perinatally with an aromatase inhibitor.

The effects of maternal exposure to aromatase inhibitor during the perinatal period of sexual brain differentiation were studied. The fertility was assessed in adult, male rat offspring of aromatase inhibitor-treated dams. The following results were obtained: (1) Sexual maturation, body weight, and wet weights of testis, pituitary, seminal vesicle, ventral prostate, and levatori ani muscle were unchanged at adult life. (2) Fifty percent of the animals were able to mate with normal females, which became pregnant but exhibited an increased number of preimplantation loss. (3) There was a decrease in the number of spermatozoa found in the testes and in the daily sperm production. (4) Of those, 25% of the male rats treated with aromatase inhibitor did not present male sexual behavior, showing female behavior when pretreated with estrogen. These results indicate that perinatal exposure to aromatase inhibitor during the critical period of male brain sexual differentiation has a long-term effect on the reproductive physiology and behavior of male rats.

Testicular reabsorption in adult males of Melipona bicolor bicolor lepeletier (Hymenoptera, Apidae, Meliponini)

The present paper reports morphological features of the testes reabsorption in adult male of Melipona bicolor bicolor. The ultrastructural features of the degenerating sperm cells and cyst cells are described. It is suggested that the material of the reabsorbed testes may serve as nutritional source for the adult male.

Efeitos do tabagismo nos parâmetros seminais

Objectives: We performed a study to evaluate the adverse effects of smoker patient on semen parameters. Material and Methods: We studied retrospective 238 semen specimen, 115 from men smoking and 123 from men nosmoking. Sperm concentration, motility, morphology and vitality were confront in statistic test. Results: In 31% smoke between 1 and 10 cigarettes per day, 26% smoked 10 and 19 per day, 42% smoke more than 20 per day. The distribution of heavy smokes and light smokes did not differ statistically between the groups. Only a significant difference found between smoker and controls, there was about motility, morphology. There is difference in vitality and concentration per ml. Conclusions: This study indicates only a minor effect of smoker patient on male subfertility. Although smokers as a group may not experience reduced fertility, men with marginal semen quality may benefit from quitting smoking.

Spermiophagy in the spermatheca of Melipona bicolor lepeletier, 1836 (Hymenoptera, Apidae, Meliponini)

The presence of spermatozoa in vesicles in the cytoplasm of the epithelial cells that constitute the spermathecal wall of Melipona bicolor queen (Meliponini) is discussed in relation to the organ structure. The epithelial wall is lined by an apparently continuous cuticle in the luminal surface that should be a non-transposable barrier to the luminal spermatozoa. However, some spermatozoa were seen crossing the cuticle through interruptions that was first interpreted as sectioning defects. Nevertheless, the sperm cells in well-structured cytoplasmic vesicles, bound by membranes and sometimes associated to multivesicular bodies, as well as cytoplasmic structures representative of intracellular digestion and the occurrence of the phenomenon in two of the three spermathecae studied, suggest a real spermiophagic hole in the spermathecal epithelial cells.

Morphology of the vas deferens of the budgerigar (Melopsittacus undulatus)

A morphological study of the budgerigar vas deferens was conducted to demonstrate the electron-microscopic features of its epithelial lining. The analysis showed that the vas deferens of the budgerigar was found to be of a tubular and serpentine structure, continuous with the epididymal region and lined with stereo ciliated pseudostratified epithelium, which contained folds projecting into the tubular lumen and a characteristic brush border. The epithelium consists of ciliated and non-ciliated cells with different electron densities. Ciliated cells were characterized by two morphologically distinct configurations: some cells were columnar and other ciliated cells were longer, thinner and dark. Non-ciliated cells showed apical cytoplasmic expansions, which projected into the tubular lumen as protrusions.