M A de las Heras

Learn More
Daily variations in melatonin content and 2-[125I]melatonin specific binding in retinas of golden hamsters were studied. Both parameters showed significant variations throughout the 24 h period. Maximal specific binding was observed at 24.00 h, while melatonin content peaked at 04.00 h. Saturation studies performed at 12.00 and 24.00 h indicated that the(More)
We have evaluated the capacitating effect of gamma-aminobutyric acid (GABA) in ram spermatozoa in vitro, in a chemically defined medium, by means of the chlortetracycline (CTC) binding assay. Semen from adult Australian Merino rams was collected in an artificial vagina; spermatozoa were washed once in modified Biggers, Whitten, and Wittingham medium(More)
High K+ medium and glutamate elicited a significant [3H]-GABA release in the golden hamster retina. High K+ -induced GABA release was largely calcium-dependent, while the effect of glutamate was Ca2+ -independent. After replacing Na+ by Li+, glutamate-evoked [3H]-GABA release was abolished, while high K+ -evoked release remained unchanged. The effect of(More)
Flutamide is a nonsteroidal antiandrogen that blocks androgen receptors, with a consequent increase in serum immunoreactive LH (I-LH) in the presence of high testosterone concentrations. Several studies suggested that the gonadal steroids also play an important role in the regulation of LH bioactivity (B-LH). Therefore, it seems difficult to understand how(More)
  • 1