Showing papers by "Jaume Reventós published in 2002"

Androgen-binding protein and reproduction: where do we stand?

Abstract: Androgen-binding protein (ABP) is a testicular glycoprotein (French and Ritzen, 1973; Danzo et al, 1974; Danzo and Black, 1990) that binds androgens with high affinity (Westphal, 1986) and transports them to the epididymis (French and Ritzen, 1973). The first evidence of ABPs existence came from the early 1970s, when a protein with a steroid-binding activity similar to the androgen receptor was detected in rat testis (French and Ritzen, 1973; Danzo et al, 1974). Subsequent studies revealed that the protein was secreted by rat Sertoli cells (Fritz et al, 1974; Tindall et al, 1974) and was very similar to a plasma protein described a few years earlier that was produced by the liver and bound dihydrotestosterone (DHT), testosterone, and estradiol (Hammond et al, 1987). The plasma protein is referred to by a variety of names, including sex hormone-binding globulin (SHBG), sex steroid–binding protein (SBP), and testosterone–estradiol–binding globulin (Joseph, 1994). Further purification of both proteins by affinity chromatography (Musto et al, 1980), as well as their characterization by photoaffinity labeling (Danzo et al, 1980) and immunoassay (Cheng et al, 1984), confirmed that ABP and SHBG were very similar physicochemically. The determination of the complete amino acid sequence of human SHBG/ABP (Walsh et al, 1986) and the cloning of the rat ABP (Joseph et al, 1985; Reventos et al, 1986) and human SHBG/ABP (Hammond et al, 1987) complementary DNAs (cDNAs) proved that both proteins share the same primary amino acid sequence, even though they differ in their carbohydrate content (Danzo and Bell, 1988). Lastly, results from Southern blot

Naturally occurring cell death during postnatal development of rat skeletal muscle.

Abstract: Naturally occurring cell death has been extensively analyzed in many tissues, but little data exist regarding its occurrence in developing skeletal muscle. We investigated its occurrence and time course in rat hindlimb skeletal muscles during the first 3 weeks of postnatal development, its morphological and biochemical features, and the concomitant expression of Bax, Bcl-2, and Bcl-x(L). Myofibers displaying morphological features of apoptosis were found during the first 9 postnatal days. Terminal transferase (TdT)-mediated dUTP-biotinylated nick end labeling (TUNEL)-positive nuclei were present at all days examined and peaked between postnatal days 5 and 7. Total genomic DNA extracted from muscles at postnatal days 5, 7, and 9 showed internucleosomal fragmentation after Southern hybridization. Constitutive levels of Bax, Bcl-2, and Bcl-x(L) were detected by means of reverse transcriptase-polymerase chain reaction (RT-PCR) analysis at all ages examined, with a moderate increase around the period of maximal apoptosis. The results show that apoptosis and a concurrent expression of some genes of the Bcl-2 family, occur postnatally in rat skeletal muscle. This information is relevant to studies addressing the mechanisms of developmental muscle injuries.