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B A Hyde

Publications and source records attributed to B A Hyde.

4 recordsLinked to original sources

Differential regulation of progestin receptor immunoreactivity in the rabbit oviduct.

Cellular distribution of progestin receptor immunoreactivity (PR-IR) in paraffin-embedded rabbit oviduct tissue was determined using a monoclonal antibody and the indirect immunoperoxidase method. Ampullar and isthmic tissue from ovariectomized animals primed with 17 beta-estradiol or vehicle alone was examined. As expected, in the absence of estradiol, PR-IR was rarely observed in the ampulla. Estradiol treatment increased PR-IR in cell nuclei of the stroma and muscularis of the ampulla, but not of the epithelium. In contrast, PR-IR was seen in epithelial cell nuclei of the isthmus in the absence of estradiol. Surprisingly, while estradiol treatment increased PR-IR in cell nuclei of the stroma and muscularis of the isthmus, it decreased PR-IR in the epithelium. These results suggest for the first time a differential regulation of progestin receptors in the ampulla and isthmus of the oviduct. In particular, while estradiol treatment increased PR-IR in the stroma and muscularis and was without effect on PR-IR in the epithelium of the ampulla, it decreased PR-IR in the epithelium of the isthmus.

Animals↗

Synthesis and secretion of sulphated glycoproteins by rabbit oviduct explants in vitro.

The ability of rabbit oviduct explants to incorporate radiolabelled precursors into specific secretory products was investigated. Ampullary and isthmic oviduct segments were cultured in the presence of [3H]glucosamine or [35S]sodium sulphate. Medium samples were analysed for the presence of secreted, labelled macromolecules. Explants incorporated the [3H]glucosamine and secreted labelled glycoproteins in vitro. SDS gel electrophoresis and subsequent fluorographic analysis of culture medium demonstrated a differential secretion of glycoproteins between the ampulla and the isthmus. Although ampullary tissue secreted a greater amount of labelled glycoproteins during the sampling period, the major secretory constituent of Mr approximately 66,000 was common to both oviduct segments. Tissue incubated with [35S]sodium sulphate also secreted a labelled glycoprotein or subunit of Mr approximately 66,000. The results indicate that rabbit oviduct explants are capable of synthesis and secretion of specific sulphated glycoproteins in vitro and that there is a difference in the type and amount of secretion produced between the two oviduct segments.

Animals↗

Sodium flux ratio through the amiloride-sensitive entry pathway in frog skin.

The sodium flux ratio of the amiloride-sensitive Na+ channel in the apical membrane of in vitro Rana catesbeiana skin has been evaluated at different sodium concentrations and membrane potentials in sulfate Ringer solution. Amiloride-sensitive unidirectional influxes and effluxes were determined as the difference between bidirectional 22Na and 24Na fluxes simultaneously measured in the absence and presence of 10(-4) M amiloride in the external bathing solution. Amiloride-sensitive Na+ effluxes were induced by incorporation of cation-selective ionophores (amphotericin B or nystatin) into the normally Na+-impermeable basolateral membrane. Apical membrane potentials (Va) were measured with intracellular microelectrodes. We conclude that since the flux ratio exponent, n', is very close to 1, sodium movement through this channel can be explained by a free-diffusion model in which ions move independently. This result, however, does not necessarily preclude the possibility that this transport channel may contain one or more ion binding sites.

Amiloride↗