Phosphorylated BRCA1 is predominantly located in the nucleus and mitochondria.

Multiple copies of the mitochondrial genome in eukaryotic cells are organized into protein-DNA complexes called nucleoids. Mitochondrial genome repair mechanisms have been reported, but they are less well characterized than their nuclear counterparts. To expand our knowledge of mitochondrial genome maintenance, we have studied the localization of the BRCA1 protein, known to be involved in nuclear repair pathways.

Hypothalamic 5 alpha-reductase and 3 alpha-oxidoreductase activity in the male rat.

The aim of the present study was to assess the progesterone (Pr) transforming 5 alpha-reductase (5 alpha-R) and 3 alpha-oxidoreductase (3 alpha-OR) activities in the hypothalamus of the male rat as a function of age and following castration and/or adrenalectomy performed at the sixth day of life. The hypothalamic activity of these enzymes was estimated from the sum of the 5 alpha- or 3 alpha-reduced metabolites produced from 14C-labeled Pr incubated "in vitro" with hypothalamic tissue. Plasma levels of testosterone (T), progesterone (Pr), estrone (E1), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured simultaneously.

Progesterone-transforming enzyme activity in the hypothalamus of the male rat.

The aim of the present study was to assess the activities of the progesterone (Pr) transforming enzyme systems 3alpha-oxidoreductase (3alpha-OR), 5alpha-reductase (5alpha-R) and 20alpha-oxidoreductase (20alpha-OR) in the hypothalamus of the male rat, at different stages of sexual maturation and following castration and adrenalectomy. Special attention was paid to transformation to 3alpha-reduced compounds previously shown to inhibit FSH synthesis and secretion. Homogenates of hypothalamic tissue were incubated with 14C-progesterone.

On the validity of blood flow measurement using colored microspheres.

The aim of this study was 1) to investigate the validity of repeated estimations of blood flow using colored microspheres (CMS) and 2) to develop and validate a method that permits four consecutive estimations in the same animal using nonradiolabeled microspheres (NRMS). Several mixtures of different types of microspheres were injected in dogs, with each mixture containing the radiolabeled microspheres (RMS; labeled with 113Sn) with either three CMS, four CMS, or three CMS and one type of fluorescent (crimson labeled) microsphere (FMS). The blood flows estimated with the use of any of the injected microspheres were compared with those measured using the RMS as the "gold standard.

Buccal absorption of testosterone and its esters using a bioadhesive tablet in dogs.

Purpose: As the oral bioavailability of testosterone is very low because of its high first pass effect, buccal administration might present a viable alternative. In this study a buccal bioadhesive tablet was used in order to sustain the delivery and bypass the liver.

Methods: Testosterone and testosterone acetate, propionate, enanthate and decanoate were investigated.