RESUMEN
OBJECTIVE: To investigate whether osteocytic connexin 43 (Cx43) is required for the bone response to intermittent PTH administration, and whether the connexin is involved in maintaining the bone matrix. METHODS: Human PTH(1-34) was injected to adult male mice expressing (Cx43(fl/fl)) or not osteocytic Cx43 (Cx43(fl/fl);DMP1-8kb-Cre) daily (100 µg/kg/d) for 14 days. RESULTS: Cx43(fl/fl);DMP1-8kb-Cre mice have no difference in body weight and BMD from 1 to 4 months of age. Intermittent PTH administration increased BMD and BV/TV and induced a similar increase in type I collagen, alkaline phosphatase, runx2, osteocalcin, and bone sialoprotein expression in mice from both genotypes. On the other hand, osteocytic deletion of Cx43 did not alter mRNA levels of glycosaminoglycans, proteoglycans, collagens and osteoblast-related genes. In addition, expression of collagens assessed by immunohistochemistry was not affected by deleting osteocytic Cx43. However, PTH administration increased type II collagen only in Cx43(fl/fl) control mice, whereas hormone increased type I collagen expression only in Cx43(fl/fl);DMP1-8kb-Cre mice. Furthermore, PTH increased maturity of collagen fibers in control, but not in Cx43-deficient mice. CONCLUSION: Expression of Cx43 in osteocytes is dispensable for bone anabolism induced by intermittent PTH administration; but it can modulate, at least in part, the effect of PTH on the bone matrix environment.
Asunto(s)
Densidad Ósea/efectos de los fármacos , Huesos/metabolismo , Conexina 43/metabolismo , Osteogénesis/efectos de los fármacos , Hormona Paratiroidea/farmacología , Absorciometría de Fotón , Animales , Huesos/efectos de los fármacos , Humanos , Inmunohistoquímica , Masculino , Ratones , Ratones Mutantes , Osteoblastos/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Microtomografía por Rayos XRESUMEN
OBJECTIVE: To investigate the hypothesis that strenuous running is a predisposing factor for osteoarthritis. DESIGN: Wistar rats were divided into two groups: a control group (CG) and a trained group (TG). The TG underwent a strenuous treadmill running training regimen of controlled intensity, exhibiting progressively improvement of fitness over 12 weeks, running at least 55 km during this period and finally performing an ultra-endurance running exercise to exhaustion. After this period, rats from both groups were euthanized and their knees removed. The articular cartilage was dissected and submitted to histomorphometrical, histomorphological, and immunohistochemical analyses evaluating cell death pathway (caspase-3 and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL)) and inflammatory cytokines [interleukin-1α (IL-1α) and tumor necrosis factor-α (TNF-α)]. In addition, the tissues were analyzed regarding the types and the content of glycosaminoglycans. RESULTS: The TG knee joints exhibited increase in the number of chondrocytes and chondrocyte clusters, as well as significantly increased levels of caspase-3, a protein involved in apoptosis, and of inflammatory cytokines IL-1α and TNF-α. In addition, histologically higher grades of osteoarthritis (Osteoarthritis Research Society International - OARSI grading), and significantly decreased levels of chondroitin sulfate and hyaluronic acid. Knee cartilage thickness and TUNEL did not significantly differ between the two groups. CONCLUSIONS: The articular cartilage of rats subjected to a strenuous running regimen of controlled intensity exhibited molecular and histological characteristics that are present in osteoarthritis.
Asunto(s)
Cartílago Articular/patología , Glicosaminoglicanos/metabolismo , Carrera , Animales , Cartílago Articular/metabolismo , Estudios de Casos y Controles , Caspasa 3/metabolismo , Muerte Celular , Condrocitos/metabolismo , Sulfatos de Condroitina/metabolismo , ADN Nucleotidilexotransferasa/metabolismo , Ácido Hialurónico/metabolismo , Interleucina-1alfa/metabolismo , Masculino , Ratas , Ratas Wistar , Rodilla de Cuadrúpedos/patología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The present work reports the differences between the ovarian grow in queen and worker larvae of A. mellifera, from the start of differential feeding. The observations made of the growth rates in larvae of both castes showed that the queen and worker larvae have the same rates of cephalic capsule growth from one instar to another but the weight gain is greater in queens. In the same way, the draw areas of ovaries of queens increase more and continuously, while from the 5th instar on the ovaries of workers decrease in size. The decrease is due to a loss of ovariole numbers that starts early in the worker larvae and increases in the 4th-5th instar. The ovarian shape in queens and workers became different in the last larval instars.
Asunto(s)
Abejas/crecimiento & desarrollo , Ovario/crecimiento & desarrollo , Animales , Abejas/ultraestructura , Femenino , Larva/crecimiento & desarrollo , Larva/ultraestructura , Ovario/ultraestructura , Aumento de PesoRESUMEN
The present work reports the differences between the ovarian grow in queen and worker larvae of A. mellifera, from the start of differential feeding. The observations made of the growth rates in larvae of both castes showed that the queen and worker larvae have the same rates of cephalic capsule growth from one instar to another but the weight gain is greater in queens. In the same way, the draw areas of ovaries of queens increase more and continuously, while from the 5th instar on the ovaries of workers decrease in size. The decrease is due to a loss of ovariole numbers that starts early in the worker larvae and increases in the 4th-5th instar. The ovarian shape in queens and workers became different in the last larval instars
Asunto(s)
Animales , Femenino , Abejas , Ovario , Abejas , Larva , Ovario , Clase Social , Aumento de PesoRESUMEN
We report nuclear acid phosphatase activity in the somatic (intra-ovariolar and stromatic) and germ cells of differentiating honey bee worker ovaries, as well as in the midgut cells of metamorphosing bees. There was heterogeneity in the intensity and distribution of electron dense deposits of lead phosphate, indicative of acid phosphatase activity in the nuclei of these tissues, during different phases of post-embryonic bee development. This heterogeneity was interpreted as a variation of the nuclear functional state, related to the cell functions in these tissues
Asunto(s)
Animales , Femenino , Abejas/enzimología , Sistema Digestivo , Fosfatasa Ácida/metabolismo , Núcleo Celular/enzimología , Ovario/enzimología , Abejas/ultraestructura , Sistema Digestivo , Larva/enzimología , Larva/ultraestructura , Microscopía Electrónica , Ovario/ultraestructura , Pupa/enzimología , Pupa/ultraestructuraRESUMEN
This article 'describes the location, anatomy, histology and ontogeny of adult Schwarziana quadripunctata exocrine glands. These glands appear either as individualized organs (salivary gland system and Dufour gland) or as epidermis differentiation (tegumentary glands). Variations in the occurrence and degree of development among colony components with regard to their degree of maturity are also described.
Asunto(s)
Abejas/anatomía & histología , Glándulas Exocrinas/anatomía & histología , Animales , Glándulas Exocrinas/citología , Femenino , MasculinoRESUMEN
This article describes the location, anatomy, histology and ontogeny of adult Schwarziana quadripunctata exocrine glands. These glands appear either as individualized organs (salivary gland system and Dufour gland) or as epidermis differentiation (tegumentary glands). Variations in the occurrence and degree of development among colony components with regard to their degree of maturity are also described