Effects of flaxseed flour on the lipid profile of rats submitted to prolonged androgen stimuli / Efectos de la harina de semilla de linaza en el perfil lipídico de ratas sometidas a estímulos androgénicos prolongados

Background: The chronic use of steroid hormones can lead to alterations in the lipid profile such as an increase in LDL and decrease in HDL levels . The effect of flaxseed on lipid profiles has been widely investigated. Aim: Evaluate the lipid profile of adult male Wistar rats fed with flax based meals and submitted to androgenic hyperstimulation. Material and Methods: Forty Wistar rats were divided into 4 groups of 10 animals: the Control group (CG); Flax group (FG) fed a flaxseed flour-based meal; Induced group (IG); and the Induced group (IGF) that was fed a flaxseed flour-based meal. The induction was done by using silicone pellets filled with testosterone propionate (1mg), sealed with a surgical adhesive and substituted every 4 weeks. Results: Triglycerides (FG: 71.16 ± 21.95; IG: 99.16 ± 26.00 and IGF: 86.33 ± 27.16 mg/dL) and HDL-cholesterol (FG: 23.05 ± 1.67; IG: 29.06 ± 7.24 and IGF: 26.06 ± 3.56 mg/dL) were significantly lower in the experimental groups. The FG and IGF (41.16 ± 3.97 and 49.66 ± 11.25 mg/dL, respectively) showed significantly lower levels of cholesterol than the other groups(CG: 78,85 ± 11.58 and IG: 70,83 ± 14.85 mg/dL). Regarding LDL levels, the IG showed significantly higher concentrations (21,93 ± 8,84 mg/dL) than the others groups (CG: 7,81 ± 5,37; FG: 3,88 ± 1,32 and IGF: 6,66 ± 7,24 mg/dL). Conclusions: The flaxseed has a relevant effect on the lipid profile of animals submitted to androgenic hyperstimulation (AU)

Introducción: El uso crónico de hormonas esteroides puede causar alteraciones en el perfil lipídico como el aumento de las LDL y reducción de las HDL. Los efectos de la linaza en el perfil lipídico han sido extensivamente investigados. Objetivo: Evaluar el perfil lipídico de ratas Wistar machos adultos alimentados con piensos a base de linaza y sometidos a hiperestimulaciones androgénicas. Materiales y Métodos: Cuarenta ratas Wistar fueron divididos en 4 grupos de 10 animales: Grupo control (GC); Grupo de linaza (GL), alimentados con piensos a base de harina de linaza ; Grupo Inducido (GI); y Grupo Inducido (GIL) alimentados con piensos a base de harina de linaza. La inducción fue realizada utilizando pellets de silicona rellenados con propionato de testosterona (1 mg) cerrados con un adhesivo quirúrgico y sustituidos cada 4 semanas. Resultados: Los triglicéridos (GL: 71.16 ± 21.95; GI: 99.16 ± 26.00; GIL: 86.33 ± 27.16 mg/dL) y colesterol-HDL (GL: 23.05 ± 1.67; GI: 29.06 ± 7.24; GIL: 26.06 ± 3.56 mg/dL) estaban significativamente más bajos en los grupos experimentales. EL GL (41.16 ± 3.97 mg/dL) y GIL (49.66 ± 11.25 mg/dL) presentaron niveles menores de colesterol que los otros grupos (GC: 78,85 ± 11.58; GI: 70,83 ± 14.85 mg/dL) y el GI concentraciones significativamente mayores de LDL (21,93 ± 8,84 mg/dL) que los otros grupos (GC: 7,81 ± 5,37; GL: 3,88 ± 1,32; GIL: 6,66 ± 7,24 mg/dL). Conclusión: La linaza presenta efectos relevantes en el perfil lipídico de animales sometidos a hiperestimulaciones androgénicas (AU)

Sex steroid communication in the ring dove brain during courtship.

This review examines possible role of progesterone receptor (PR) and androgen receptor (AR) "cross-talk" in the expression of courtship behaviour in the ring dove (Streptopelia risoria). In doves, although androgen has been mostly associated with aggressive courtship behaviour and progesterone with the initiation of incubation, progesterone administration to courting birds terminates the aggressive component of courtship whilst having no effect on nesting behaviour. Recent results in doves have identified a high density of androgen receptor and progesterone receptor immunoreactivity (AR-ir and PR-ir) in the hypothalamus of both sexes in regions known to be directly involved in courtship and incubation behaviour. Nuclear AR-ir in courting birds is widespread throughout the brain. Nuclear PR-ir is only localized in discrete regions of the preoptic hypothalamus of both sexes. In the anterior and posterior hypothalamus of courting birds an increase number of AR-ir and PR-ir neurons colocalizes (70-90%) in the nucleus preopticus anterior (POA), nucleus preopticus medialis (POM), nucleus preopticus paraventricularis magnocellularis (PPM), nucleus hypothalami lateralis posterioris (PLH), and tuberal hypothalamus (Tu). A lower percentage of colocalization is seen in birds at other stages of the breeding cycle. The high percentage of AR-ir and PR-ir colocalization in the preoptic hypothalamus of courting doves supports previous reports involving progesterone acting in these brain regions to terminate the androgen-dependent aggressive courtship behaviour in male doves. The increase in PR-ir staining intensity in AR-ir neurons in courting birds suggests that this progesterone-dependent termination of aggressive courtship display in males occurs at the receptor level and may be orchestrated by central oestrogen.

Ex vivo bioadhesion and in vivo testosterone bioavailability study of different bioadhesive formulations based on starch-g-poly(acrylic acid) copolymers and starch/poly(acrylic acid) mixtures.

Starch-g-poly(acrylic acid) copolymers or grafted starches synthesized by 60Co irradiation or chemical modification and co-freeze-dried starch/poly(acrylic acid) mixtures were evaluated on their ex vivo bioadhesion capacity. The buccal absorption of testosterone from a bioadhesive tablet formulated with the grafted starches or starch/poly(acrylic acid) mixtures was investigated. The results were compared to a reference formulation (physical mixture of 5% Carbopol 974P and 95% Drum Dried Waxy Maize). Rice starch-based irradiated grafted starches showed the best bioadhesion results. Partial neutralization of the acrylic acid with Ca(2+) ions resulted in significantly higher bioadhesion values compared to the reference. Ca(2+) and Mg(2+) partially neutralized maltodextrin-based irradiated grafted starches showed significantly higher bioadhesion values compared to the reference formulation. The chemically modified grafted starches showed significantly higher adhesion force values than for the reference tablet. None of the co-freeze-dried starch/poly(acrylic acid) mixtures showed significantly higher bioadhesion results than the reference (Bonferroni test, P<0.05). A chemically modified grafted starch could sustain the 3 ng/ml plasma testosterone target concentration during +/- 8 h (T(>3 ng/ml)). By lyophilization of a partially neutralized irradiated grafted starch, the in vivo adhesion time (22.0 +/- 7.2 h) and the T(>3 ng/ml) (13.5 +/- 1.3 h) could be increased. The absolute bioavailability of the lyophilized formulation approached the reference formulation. Some of the grafted starches showed to be promising buccal bioadhesive drug carriers for systemic delivery.