Ana Paula Tanno

Bio: Ana Paula Tanno is an academic researcher from State University of Campinas. The author has contributed to research in topics: Nandrolone & Muscle hypertrophy. The author has an hindex of 10, co-authored 22 publications receiving 1461 citations. Previous affiliations of Ana Paula Tanno include College of Health Sciences, Bahrain.

Determination of the estrous cycle phases of rats: some helpful considerations

Abstract: The short length of the estrous cycle of rats makes them ideal for investigation of changes occurring during the reproductive cycle. The estrous cycle lasts four days and is characterized as: proestrus, estrus, metestrus and diestrus, which may be determined according to the cell types observed in the vaginal smear. Since the collection of vaginal secretion and the use of stained material generally takes some time, the aim of the present work was to provide researchers with some helpful considerations about the determination of the rat estrous cycle phases in a fast and practical way. Vaginal secretion of thirty female rats was collected every morning during a month and unstained native material was observed using the microscope without the aid of the condenser lens. Using the 10 x objective lens, it was easier to analyze the proportion among the three cellular types, which are present in the vaginal smear. Using the 40 x objective lens, it is easier to recognize each one of these cellular types. The collection of vaginal lavage from the animals, the observation of the material, in the microscope, and the determination of the estrous cycle phase of all the thirty female rats took 15-20 minutes.

Influence of high-intensity exercise training and anabolic androgenic steroid treatment on rat tissue glycogen content.

Abstract: To increase tissue glycogen content many athletes use anabolic androgenic steroids (AAS). However, the literature concerning the effects of androgens on glycogen metabolism is conflicting. This study aimed to determine the influence of training and AAS on body weight (bw), triglycerides, glucose, tissue glycogen and transaminases levels. Male Wistar rats, randomized into four groups (sedentary vehicle (SV), sedentary AAS (SA), trained vehicle (TV) and trained AAS (TA)), were treated with nadrolone (5 mg/Kg, 2x/week, i.m.) or vehicle. Trained rats performed jumps into water (4 sets, 10 repetitions, 30 sec rest) carrying a 50-70% body wt-load strapped to the chest (5 days/week,6 weeks). Two days after the last session, the animals were killed (bifatorial ANOVA+Tukey test; P SV:0.13+/-0.01=TV:0.13+/-0.01=SA:0.14+/-0.01 mg/100 mg). In the soleus AAS increased glycogen (SA:0.53+/-0.03 vs. SV:0.43+/-0.01 and TA:0.58+/-0.02 vs. TV:0.48+/-0.01 mg/100 mg). Exercise training and AAS had no effect on blood glucose and transaminases levels. Training and AAS effects on glycogen supercompensation are tissue-dependent and the effects of association between them were only observed in the cardiac muscle. These data emphasize the necessity of more studies to confirm greater effects of AAS than those promoted by physical exercise.

Vascular Sensitivity to Phenylephrine in Rats Submitted to Anaerobic Training and Nandrolone Treatment

Abstract: The effect of anaerobic physical training and nandrolone treatment on the sensitivity to phenylephrine in thoracic aorta and lipoprotein plasma levels of rats was studied. Sedentary and trained male Wistar rats were treated with vehicle or nandrolone (5 mg/kg IM; twice per week) for 6 weeks. Training was performed by jumping into water (4 sets, 10 repetitions, 30-second rest, 50% to 70% body weight load, 5 days/week, 6 weeks). Two days after the last training session, the animals were killed and blood samples for lipoprotein dosage were obtained. Thoracic aorta was isolated and concentration-effect curves of phenylephrine were performed in intact endothelium and endothelium-denuded aortic rings in the absence or presence of NG-L-arginine-methyl ester. No changes were observed in endothelium-denuded aortic rings. However, in endothelium-intact thoracic aorta, anaerobic physical training induced subsensitivity to phenylephrine (pD2=7.11+/-0.07) compared with sedentary group (7.55+/-1.74), and this effect was canceled by the inhibition of nitric oxide synthesis. No difference was observed between trained (7.22+/-0.07) and sedentary (7.28+/-0.09) groups treated with nandrolone. Anaerobic training induced an increase in high-density lipoprotein levels in vehicle-treated rats, but there were no changes in nandrolone-treated groups. Training associated with nandrolone induced an increase in low-density lipoprotein levels but no change in the other groups. If altering endothelium-dependent vasodilatation is considered to be a beneficial adaptation to anaerobic physical training, it is concluded that nandrolone treatment worsens animals' endothelial function, and this effect may be related to lipoprotein blood levels.

Assessing Reproductive Status/Stages in Mice

Abstract: The short reproductive cycle length observed in rodents, called the estrous cycle, makes them an ideal animal model for investigation of changes that occur during the reproductive cycle Most of the data in the literature about the estrous cycle is obtained from rats because they are easily manipulated and they exhibit a clear and well-defined estrous cycle However, the increased number of experiments using knockout mice requires identification of their estrous cycle as well, since (in)fertility issues may arise In mice, like rats, the identification of the stage of estrous cycle is based on the proportion of cell types observed in the vaginal secretion The aim of this unit is to provide guidelines for quickly and accurately determining estrous cycle phases in mice

A New Rat Model Exhibiting Both Ovarian and Metabolic Characteristics of Polycystic Ovary Syndrome

Abstract: Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder associated with ovulatory dysfunction, hyperandrogenism, abdominal obesity, and insulin resistance. However, its etiology is unclear, and its management is often unsatisfactory or requires a diversified approach. Here, we describe a new rat PCOS model, the first to exhibit both ovarian and metabolic characteristics of the syndrome. Female rats received the nonaromatizable androgen dihydrotestosterone (DHT) or the aromatase inhibitor letrozole by continuous administration, beginning before puberty, to activate androgen receptors. Adult DHT rats had irregular cycles, polycystic ovaries characterized by cysts formed from atretic follicles, and a diminished granulosa layer. They also displayed metabolic features, including increased body weight, increased body fat, and enlarged mesenteric adipocytes, as well as elevated leptin levels and insulin resistance. All letrozole rats were anovulatory and developed polycystic ovaries with structural changes strikingly similar to those in human PCOS. Our findings suggest that the formation of a "hyperplastic" theca interna reflects the inclusion of luteinized granulosa cells in the cyst wall rather than true hyperplasia. We conclude that the letrozole model is suitable for studies of the ovarian features of human PCOS, while the DHT model is suitable for studies of both ovarian and metabolic features of the syndrome.