Obesity-induced skeletal muscle remodeling: A comparative analysis of exercise training and ACE-inhibitory drug in male mice.

Obesity over-activates the classical arm of the renin-angiotensin system (RAS), impairing skeletal muscle remodeling. We aimed to compare the effect of exercise training and enalapril, an angiotensin-converting enzyme inhibitor, on RAS modulation in the skeletal muscle of obese animals. Thus, we divided C57BL/6 mice into two groups: standard chow (SC) and high-fat (HF) diet for 16 weeks. At the eighth week, the HF-fed animals were divided into four subgroups-sedentary (HF), treated with enalapril (HF-E), exercise training protocol (HF-T), and combined interventions (HF-ET). After 8 weeks of treatment, we evaluated body mass and index (BMI), body composition, exercise capacity, muscle morphology, and skeletal muscle molecular markers. All interventions resulted in lower BMI and attenuation of overactivation in the classical arm, while favoring the B2R in the bradykinin receptors profile. This was associated with reduced apoptosis markers in obese skeletal muscles. The HF-T group showed an increase in muscle mass and expression of biosynthesis markers and a reduction in expression of degradation markers and muscle fiber atrophy due to obesity. These findings suggest that the combination intervention did not have a synergistic effect against obesity-induced muscle remodeling. Additionally, the use of enalapril impaired muscle's physiological adaptations to exercise training.

Histological study and immunohistochemical location of cytoskeletal proteins in the ovaries of the three species of lizards of the family Leiosauridae (Reptilia: Squamata).

The aim of the study is to expand information on the histological aspect, presence, and distribution of cytoskeletal proteins: smooth muscle alpha-actin (α-SMA), desmin and vimentin in ovaries of three lizards Leiosauridae. In all analysed species, the ovaries were paired organs, located inside the coelomic cavity, covered in a simple cubic epithelium. Below the surface was the tunica albuginea. The organs can be divided into two regions: the cortex and the medulla. The pre-vitellogenic follicles consist of an oocyte surrounded by the pellucid zone periodic acid schiff positive, the granulosa layer consisting of three cell types: small, intermediate, and large and the theca layer. The vitellogenic follicles presented only a single layer of cubic granulosa cells. In the three lizards, α-SMA microfilaments (MFs) were verified along the theca layer and in endothelial cells of the blood vessels of the analysed follicles. Researchers have observed desmin intermediate filaments immunostaining exclusively muscle fibers of the albuginea and the ovarian stroma of Enyalius perditus. There was no immunostaining for vimentin in the ovaries of all the lizards studied. Results obtained revealed that the MFs of α-SMA could be responsible for a contractile activity present in the lizards assessed.

Influence of feeding habits in the endocrine pancreas of insectivore bat Pteronotus personatus and nectarivore bat Anoura geoffroyi: A comparative stereological and immunohistochemical study.

Pteronotus personatus as an insectivore bat and has a diet that consists of a high protein diet, whereas the diet of Anoura geoffroyi, a predominantly nectarivore bat, is rich in simple sugars like sucrose, glucose and fructose. Considering that diet influences the activation of different pathways, which may influence morphological adaptations in the gastrointestinal system, the aim of this study was to compare the morphology of the endocrine pancreas in P. personatus and A. geoffroyi. For this, histological, stereological and immunohistochemical methods were used. In P. personatus, the average diameter of the pancreatic islet was 40.47µm±13.94, while in A. geoffroyi was 88.16µm±36.40. The total number of pancreatic islets in P. personatus was 26150±2346 and in A. geoffroyi was 15970±1666. In P. personatus, the volume density of the pancreatic islets was 3.4%± 2.6, whereas in A. geoffroyi the volume density was 6.1%±3.7. In addition, the immunodensity of the α, ß and δ cells, in P. personatus was 25.8%±11.9, 35.5%±13.5, 3.9%±0.7, respectively, and in A. geoffroyi was 33.10%±12.7, 55.08%±7.4, 6.2%±4.6, respectively. In conclusion, the results of this study indicate differences in the pancreatic weight/body, weight ratio, diameter and volume density of pancreatic islets and in immunodensity of the ß and α cells between both species, which have different dietary habits.

Histological and immunohistochemical study of the thyroid gland of the broad-snouted caiman (Caiman latirostris) - doi: 10.4025/actascibiolsci.v35i4.18444

The broad-snouted caiman, Caiman latirostris, is widely distributed in countries of South America. In Brazil it is considered an endangered species because of natural habitat destruction and illegal hunting.  In reptiles, the thyroid gland plays an integral part in ecdysis, reproduction, tail regeneration, growth, endocrine function and metabolism rate. The aim of the present study was to characterize the thyroid gland morphology of C. latirostris, based on histochemical and immunohistochemical techniques. The thyroid glands were fixed in Bouin"s fluid and serial cross sections were stained with hematoxylin-eosin, Mallorys trichrome, periodic acid-Schiff (PAS) and Alcian blue (AB pH 1.5 and 2.5). The immunohistochemical technique for 5-HT-IR cells was used. The thyroid gland has a dense irregular connective tissue forms a capsule enveloping the gland. There are several follicular acini of varying size lined by simple cuboidal or columnar epithelium in the thyroid gland. The follicles are connected by interfollicular connective tissue which contains blood vessels. We observed the presence of lymph nodes around the entire gland. There was a positive PAS reaction and negative AB reaction in the colloid. 5-HT-IR cells were detected around the follicle cells. No striking morphological differences were observed between C. latirostris and other domesticated mammals.

Histological and immunohistochemical study of the thyroid gland of the broad-snouted caiman (Caiman latirostris) / Estudo histológico e imuno-histoquímico da glândula tireoide do jacaré do papo-amarelo (Caiman latirostris)

The broad-snouted caiman, Caiman latirostris, is widely distributed in countries of South America. In Brazil it is considered an endangered species because of natural habitat destruction and illegal hunting. In reptiles, the thyroid gland plays an integral part in ecdysis, reproduction, tail regeneration, growth, endocrine function and metabolism rate. The aim of the present study was to characterize the thyroid gland morphology of C. latirostris, based on histochemical and immunohistochemical techniques. The thyroid glands were fixed in Bouin's fluid and serial cross sections were stained with hematoxylin-eosin, Mallory's trichrome, periodic acid-Schiff (PAS) and Alcian blue (AB pH 1.5 and 2.5). The immunohistochemical technique for 5-HT-IR cells was used. The thyroid gland has a dense irregular connective tissue forms a capsule enveloping the gland. There are several follicular acini of varying size lined by simple cuboidal or columnar epithelium in the thyroid gland. The follicles are connected by interfollicular connective tissue which contains blood vessels. We observed the presence of lymph nodes around the entire gland. There was a positive PAS reaction and negative AB reaction in the colloid. 5-HT-IR cells were detected around the follicle cells. No striking morphological differences were observed between C. latirostris and other domesticated mammals.

O jacaré do papo-amarelo, Caiman latirostris, é amplamente distribuído nos países da America do Sul. No Brasil este é considerado uma espécie em extinção pela destruição de seu habitat natural e caça ilegal. Em répteis, a glândula tireoide desempenha um papel fundamental na ecdise, reprodução, regeneração da cauda, crescimento, função endócrina e na taxa de metabolismo. O objetivo do estudo foi caracterizar a morfologia da glândula tireoide de C. latirostris, com base em técnicas de histoquímica e imuno-histoquímica. As tireoides foram fixadas em Bouin e seções transversais corados com hematoxilina-eosina, Tricrômico de Mallory, ácido periódico de Schiff (PAS) e Alcian blue (AB pH 1,5 e 2,5). A técnica de imuno-histoquímica para detecção de células imunoreativas a 5-HT foi utilizada. A glândula tireoide possui uma cápsula de tecido conjuntivo denso não modelado. Há numerosos ácinos foliculares de tamanho variáveis revestidos por epitélio cúbico ou cilíndrico simples. Entre os folículos observa-se o tecido conjuntivo ricamente vascularizado. Observamos a presença de linfonodos ao redor de toda a glândula. No coloide observou-se uma reação PAS positiva e AB negativa. Células imunoreativas para 5-HT foram detectadas em torno das células foliculares. Não foram observadas diferenças histológicas marcantes na tireoide de C. latirostris quando comparadas a outros mamíferos domésticos.

What difference exists in the pancreas of mammals with sanguivorous diet? A morphological, stereological and immunohistochemical study of the pancreatic islets of the hematophagous bat Diphylla ecaudata.

Diphylla ecaudata is a vampire bat that mainly feeds on the blood of birds. This highly specialized diet - hematophagy - is accompanied by a series of morphological changes in the gastro-entero-pancreatic system, since the distribution and relative proportions of different pancreatic endocrine cell types can vary between species due to different physiological conditions and eating habits. The aim of this study was to examine for the first time the pancreas of the vampire bat D. ecaudata using morphological, stereological and immunohistochemical techniques. The pancreas of the D. ecaudata has an exocrine acinar portion in which the highest concentration of pancreatic islets is scattered. These pancreatic islets have irregular size and a mean diameter of 56.94 µm. The total number of islets in the pancreas was 23,900, with a volumetric density of 4.1%. Insulin-immunoreactive (IR) cells were located in the central pancreatic islet region and had the largest density (54.8%). Glucagon-IR cells were located mainly in the peripheral mantle region (16.2%), along with somatostatin-IR (SS) cells (14.3%). Cells immunoreactive to insulin, glucagon and somatostatin were also observed to have spread in isolated places in the exocrine pancreas. In the connective tissue near the pancreatic ducts, a high concentration was identified of insulin-IR cells and a low concentration of glucagon-IR and somatostatin-IR cells. These results indicate that although the pancreas of D. ecaudata has morphological similarities with that of other mammals, it has a differentiated islet structure, because there were a large number of islets and different volumetric densities of α, ß and δ cells.

Morfologia do funículo espermático em caprinos da raça Bhuj Brasileira / Morphology of the spermatic cord in Brazilian Bhuj goats

Estudamos em 40 caprinos adultos da raça Bhuj Brasileira os aspectos histológicos do funículo espermático. Observamos que este se acha envolvido por uma cápsula de tecido conjuntivo fibroelástico denso, de espessura variável, pregueada em alguns pontos, e revestida por mesotélio que circunda todo o conjunto vásculo-nervoso, e projeta-se para formar o mesoducto deferente. Em posição subcapsular, verifica-se uma camada de tecido conjuntivo fibroelástico frouxo, de espessura variável, que circunda parcialmente o funículo espermático, isolando nas regiões deferencial e abdeferencial, conjuntos vásculo-nervosos, responsáveis pela nutrição do epidídimo. Na região do mesoducto deferente, o tecido subcapsular acompanhado de tecido adiposo constitui a camada interna deste meso, formando a sua adventícia e abrigando vasos e nervos deferenciais. Na região abdeferencial, pequenos acúmulos de tecido adiposo são vistos de permeio aos vasos e nervos desta região. Entre as artérias, veias e nervos testiculares, bem como entre os vasos das regiões deferencial e abdeferencial, observa-se o tecido conjuntivo denso, intervascular, rico em fibras elásticas, que constitui as adventícias contínuas destes vasos. O arranjo vascular mostra que o segmento da artéria testicular, contido no funículo espermático, apresenta trajeto sinuoso. Estando envolvido pelo plexo venoso pampiniforme, formado por veias testiculares desprovidas de válvulas de calibres variados, apresentando amplas comunicações entre si. As veias responsáveis pela drenagem do epidídimo e ducto deferente estão localizadas em posição subcapsular deferencial e abdeferencial e mostram-se providas de válvulas. O trato das artérias testiculares no funículo espermático apresenta como média e desvio padrão 134,6±38,1cm à direita, e 137,0±33,9cm à esquerda, não existindo diferenças estatisticamente significantes ao nível de 5 por cento, quando comparamos a média do segmento da artéria testicular contida no funículo espermático direito em relação ao esquerdo.

Histological aspects of the spermatic cord were studied in 40 Brazilian Bhuj goats. It was seen that the spermatic cord is involved by a thin capsule of compact connective tissue recovered by mesothelium which forms an expansion, the mesodeferens. Under this capsule is a subcapsular layer of variable thickness, formed by loose elastic fiber connective tissue that mixes with deep layer of the mesodeferens and with the adventitia of ductus deferens. Between the testicular artery and testicular veins exists an intervascular compact elastic fiber connective tissue in continuity with the adventitia of spermatic cord vessels. In the abdeferential region of the spermatic cord exists a neurovascular contingent, the vessels of which generally have inferior calibers and similar constitution and arrangement as the testicular artery and veins; the described contingent is related to nutrition of the initial portion of ductus deferens and part of the epididymis head and body. The vascular arrangement shows that the segment of the testicular artery in the spermatic cord has a sinuous disposition and is totally involved by the venous plexus formed by testicular vein valves with irregular outlines, diverse calibers and large connections. The length of the intra spermatic cord segment of the testicular artery has a medium and standard deviation of 134.6±38.1cm on the right and 137±33.9cm on the left. There were no statistical differences between the right and left medium ranges.

Distributions of the endocrine cells in the gastrointestinal tract of nectarivorous and sanguivorous bats: a comparative immunocytochemical study.

The present study was conducted to clarify the influence of feeding habits on regional distribution and relative frequency of endocrine cells secreting cholecystokinin (CCK), gastrin (GAS), serotonin (5-HT) and enteroglucagon (GLUC) in the nectarivorous Anoura geoffroyi and Glossophaga soricina and the sanguivorous Desmodus rotundus bats of the Phyllostomidae family, by specific immunohistochemical methods. The regional distribution and frequency of the different types of endocrine cells varied according to their location in the GIT. 5-HT immunoreactive cells (IR), detected throughout the GIT of three bats, were the most predominant gastrointestinal endocrine cells. GAS-IR cells in A. geoffroyi were found at the base of the pyloric gland, while in G. soricina they could also be observed in the middle to basal portions of the gland. GLUC-IR cells were located in the fundic region of A. geoffroyi, G. soricina and D. rotundus. These endocrine cells were more abundant in the sanguivorous bat. In nectarivorous bats were compared to sanguivorous bat, which differ in dietary habits, difference in the distribution and relative frequency of gut endocrine cells would be predicted. The absence of some, and decrease in frequency of other, gastrointestinal endocrine cells may reflect, in part, its interspecies differences or dietary habits.