Effect of testosterone on proteoglycans in the submandibular glands of the rat.

The proteoglycans in the submandibular salivary glands of castrated male Wistar rats were studied before and after the daily administration of testosterone propionate (TP) for one month. Castration decreased the weight of the glands and their uronic acid content. The administration of TP reversed these effects. Chromatographic separation of the uronic acid fractions was performed on cellulose microcolumns. The principal fractions were hyaluronic acid, heparan sulfate and dermatan sulfate. There were also changes in the physical properties of the proteoglycans. Castration decreased the range of distribution of molecular weight and the density, while the lateral chains of smaller length disappeared. TP administration to castrated rats reversed these effects.

Effects of castration and androgens upon prostatic proteoglycans in rats.

In studies performed on male Wistar rats, castration induced atrophy of the prostate with a marked increase in the uronic acid content. The administration of testosterone propionate to castrated rats produced opposite effects. Fractionation of the glycosaminoglycans on cellulose microcolumns showed that the changes in uronic acid content in the dorsolateral lobes were due to variations in hyaluronic acid, chondroitin-4-sulfate, and dermatan sulfate, but in the ventral lobes, there were changes in all the chromatographic fractions. There were also changes in the physical properties of proteoglycans. In the ventral lobes, castration induced a wider distribution of molecular weight, increased density, and predominance of lateral chains of greater size. In the dorsolateral lobes, there was a decrease in molecular weight and density of proteoglycans and in the length of lateral chains. Opposite results were obtained when testosterone propionate was given to castrated rats. It is postulated that the effects of androgens upon prostatic growth would depend on an interrelationship between epithelium and stroma mediated by the proteoglycans.

Changes in mandible and femur proteoglycans. Physico-chemical properties after hydrocortisone treatment.

Male Wistar rats were injected with 5 mg/kg/day of hydrocortisone during 21 days. Femur and mandible proteoglycans (PG) were isolated and their physico-chemical properties were compared with bone PG from a control and a starved group. The PG molecular weight decreased as a result of the hydrocortisone treatment but to a lower degree than in starvation, whereas the PG density seemed to be more affected by corticosteroid injection. These results allow us to conclude that bone alterations found after glucosteroid treatment may be due--at least partially--to changes in the PG physico-chemical properties of that tissue.

Changes in mandible and femur proteoglycans. Physico-chemical properties after hydrocortisone treatment

Male Wistar rats were injected with 5 mg/kg/day of hydrocortisone during 21 days. Femur and mandible proteoglycans (PG) were isolated and their physico-chemical properties were compared with bone PG from a control and a starved group. The PG molecular weight decreased as a result of the hydrocortisone treatment but to a lower degree than in starvation, whereas the PG density seemed to be more affected by corticosteroid injection. These results allow us to conclude that bone alterations found after glucosteroid treatment may be due--at least partially--to changes in the PG physico-chemical properties of that tissue.

Changes in mandible and femur proteoglycans. Physico-chemical properties after hydrocortisone treatment.

Male Wistar rats were injected with 5 mg/kg/day of hydrocortisone during 21 days. Femur and mandible proteoglycans (PG) were isolated and their physico-chemical properties were compared with bone PG from a control and a starved group. The PG molecular weight decreased as a result of the hydrocortisone treatment but to a lower degree than in starvation, whereas the PG density seemed to be more affected by corticosteroid injection. These results allow us to conclude that bone alterations found after glucosteroid treatment may be due--at least partially--to changes in the PG physico-chemical properties of that tissue.

Effect of total food deprivation on the proteoglycans of rat hyaline cartilage and bone.

Existing hypotheses suggest that the effect of food deprivation on bone occurs via alterations in the synthesis of the organic matrix. Thus, this work was carried out to characterize the modifications of the physico-chemical properties of the proteoglycans (PG) of rat hyaline cartilage and femur. Male Wistar rats were assigned at random to a control group which was fed a standard pellet diet or to an experimental group which was given water "ad libitum" and starved over the experimental period. On day 4 or 8 the animals were administered a dose of 35S, weighed and killed. PG and glycosaminoglycans (GAG) were isolated from femurs and xyphoid cartilages. Uptake of 35S, GAG distribution patterns, PG molecular weight, molecular size of the side chains and the PG density gradient were determined. The aforementioned parameters decreased significantly after 4 and 8 days of total starvation. The GAG distribution pattern only exhibited a reduction of the Chondroitin-4-Sulphate fraction. These changes could alter the binding properties of PG to other macromolecules such as collagen which plays an important role in the ossification process.

Effect of total food deprivation on the proteoglycans of rat hyaline cartilage and bone.

Existing hypotheses suggest that the effect of food deprivation on bone occurs via alterations in the synthesis of the organic matrix. Thus, this work was carried out to characterize the modifications of the physico-chemical properties of the proteoglycans (PG) of rat hyaline cartilage and femur. Male Wistar rats were assigned at random to a control group which was fed a standard pellet diet or to an experimental group which was given water [quot ]ad libitum[quot ] and starved over the experimental period. On day 4 or 8 the animals were administered a dose of 35S, weighed and killed. PG and glycosaminoglycans (GAG) were isolated from femurs and xyphoid cartilages. Uptake of 35S, GAG distribution patterns, PG molecular weight, molecular size of the side chains and the PG density gradient were determined. The aforementioned parameters decreased significantly after 4 and 8 days of total starvation. The GAG distribution pattern only exhibited a reduction of the Chondroitin-4-Sulphate fraction. These changes could alter the binding properties of PG to other macromolecules such as collagen which plays an important role in the ossification process.

Alteraciones en la matriz organica del hueso y cartilago de rata por el uso prolongado de fluoruno de sodio / Alterations in the organic matrix of bone and cartilage after prolonged administration of sodium fluoride in the rat

Los fluoruros, por mecanismos aun no aclarados, estimulan la formación ósea y son, en consecuencia, usados en el tratamiento de las osteoporosis. Desde un punto de vista terapéutico, uno de los efectos más esperados por la ingesta de fluoruro en pacientes osteoporóticos es la disminución en el índice de fracturas. Si bien esto ocurre, observaciones clínicas sugieren que este efecto es menor que el esperado por el aumento de la masa ósea (ej.: la resistencia por unidad de tejido estaría disminuida en el hueso fluorótico). El o los mecanismos por los cuales el fluoruro conduce a las alteraciones mencionadas, todavía no son bien conocidos, pero como el componente inorgánico ha sido extensamente estudiado, hemos llevado a cabo este trabajo con el objeto de caracterizar cuali y cuantitativamente a los GAG y el colágeno de hueso y cartílafo de rata, en función de la ingesta prolongada de fluoruro de sodio. Las variaciones producidas por la ingesta de fluoruro implican un aumento significativo en la concentracicón de GAG, después de dos meses de tratamiento, debidas a un incremento en las fracciones correspondentes al condroitín-6-sulfato y dermatán sulfato. Esta modificación en el patrón de distribución de los GAG no es atribuible a variaciones en el peso de las moléculas. Aunque otros estudios han informado que no se observan efectos sobre la síntesis de colágeno o de DNA, como consecuencia de la ingesta de fluoruro, nuestros resultados muestran que el contenido de OH-Pro se halla aumentado significativamente luego de 2 meses de tratamiento. Los datos presentados sugieren que las alteraciones óseas inducidas por el fluoruro, podrían se, al menos en parte, debidas a cambios en la concentración y distribución de los GAG y el colágeno en la matriz calcificable de hueso y cartílago de rata

Alteraciones en la matriz organica del hueso y cartilago de rata por el uso prolongado de fluoruno de sodio / Alterations in the organic matrix of bone and cartilage after prolonged administration of sodium fluoride in the rat

Los fluoruros, por mecanismos aun no aclarados, estimulan la formación ósea y son, en consecuencia, usados en el tratamiento de las osteoporosis. Desde un punto de vista terapéutico, uno de los efectos más esperados por la ingesta de fluoruro en pacientes osteoporóticos es la disminución en el índice de fracturas. Si bien esto ocurre, observaciones clínicas sugieren que este efecto es menor que el esperado por el aumento de la masa ósea (ej.: la resistencia por unidad de tejido estaría disminuida en el hueso fluorótico). El o los mecanismos por los cuales el fluoruro conduce a las alteraciones mencionadas, todavía no son bien conocidos, pero como el componente inorgánico ha sido extensamente estudiado, hemos llevado a cabo este trabajo con el objeto de caracterizar cuali y cuantitativamente a los GAG y el colágeno de hueso y cartílafo de rata, en función de la ingesta prolongada de fluoruro de sodio. Las variaciones producidas por la ingesta de fluoruro implican un aumento significativo en la concentracicón de GAG, después de dos meses de tratamiento, debidas a un incremento en las fracciones correspondentes al condroitín-6-sulfato y dermatán sulfato. Esta modificación en el patrón de distribución de los GAG no es atribuible a variaciones en el peso de las moléculas. Aunque otros estudios han informado que no se observan efectos sobre la síntesis de colágeno o de DNA, como consecuencia de la ingesta de fluoruro, nuestros resultados muestran que el contenido de OH-Pro se halla aumentado significativamente luego de 2 meses de tratamiento. Los datos presentados sugieren que las alteraciones óseas inducidas por el fluoruro, podrían se, al menos en parte, debidas a cambios en la concentración y distribución de los GAG y el colágeno en la matriz calcificable de hueso y cartílago de rata (AU)

Pirenzepine as anti-inflammatory drug in a model of experimental colitis in rat.

Pirenzepine has been widely used for the treatment of gastric and duodenal ulcer. In this work we have proved that this drug could prevent the inflammatory reaction induced in the colon with an intraluminal stimuli as the acetic acid. These data suggest the cholinergic participation in the inflammatory colonic response.

Pirenzepine as anti-inflammatory drug in a model of experimental colitis in rat.

Pirenzepine has been widely used for the treatment of gastric and duodenal ulcer. In this work we have proved that this drug could prevent the inflammatory reaction induced in the colon with an intraluminal stimuli as the acetic acid. These data suggest the cholinergic participation in the inflammatory colonic response.

Hypoxia-induced renal and extrarenal erythropoietin production in posthypoxic or hypertransfused polycythemic rats.

The erythropoietic response, measured as 59Fe uptake by RBC, and the erythropoietin content of kidney tissue after exposure to hypobaric hypoxia were determined in both posthypoxic (PH) and hypertransfused (HT) rats. Plasma Ep titers were also measured in both PH and HT nephrectomized rats treated similarly. PH and HT rats with similar degrees of polycythemia greatly differed in their responses to hypoxia, with radioiron uptake by RBC about six times higher in the former than in the latter. Kidney Ep titers were significantly enhanced after exposure to hypoxia in either normal or polycythemic rats. However, kidney Ep titers in PH rats were significantly higher than the values found in normal or HT rats. Plasma Ep titers in both PH and HT nephrectomized rats exposed to hypoxia were similar and significantly lower than the plasma values of normal or nephrectomized, nonpolycythemic rats treated similarly. These results suggest that exposure to hypoxia induces sensitization of the renal, but not extrarenal, mechanism involved in Ep production.