1. The effect of several beta-adrenoceptor blocking drugs on the pregnant ewe and foetus were studied. Bunolol, butidrine, oxprenolol, propranolol and USVP65-24 all crossed the ovine placenta and produced a beta-adrenoceptor blockade in the ovine foetus. AH3474, AY21011 and sotalol did not cross the ovine placenta as assessed by the absence of a beta-blockade in the foetus when these compounds ...

An estimate has been made of the time required for a population of spermatozoa capable of fertilizing the egg to be established in the oviducts of heifers mated early in oestrus. During a general or local anaesthetic, the caudal isthmus of the oviduct was ligated and sectioned 6, 8, 10 or 12 hr after mating. The proportion of eggs fertilized as judged 2-4 days later was very low if ligation was...

BACKGROUND Classically, progesterone has been thought to act only through the well-known genomic pathway involving hormone binding to nuclear receptors and subsequent modulation of gene expression. However, there is increasing evidence for rapid, non-genomic effects of progesterone in a variety of mammalian tissues and it is possible that a membrane PR (mPR) is causing these events. We recently...

The purpose of this investigation was to study the expression of type X collagen in the hen's oviduct. Type X collagen is a short-chain collagen that is present in the fibers of eggshell membranes, and there is evidence to suggest that it contributes to structural integrity. In situ hybridization and Northern blot analysis were used to study the expression of this important matrix constituent. ...

Estrogen regulates reproductive behavior and drives the proliferation and differentiation of several cell types. These physiological functions of estrogen are mediated by estrogen receptors (ERs), and each ER isoform plays a distinct role. To clarify the molecular mechanism of estrogen action and to evaluate the effect of ERs on the secretion of ovalbumin (OVA) in pigeon oviduct epithelial cell...

The full-length pigeon ovalbumin (OVA) gene cDNA was cloned and sequenced by reverse transcription-polymerase chain reaction (RT-PCR) and rapid-amplification of cDNA ends. A 386-amino acid protein was predicted for the obtained sequence, which had 67% identity with the chicken protein. Similar to chicken OVA, the pigeon OVA gene is a non-inhibitory serine protease inhibitor. Quantitative PCR an...

PURPOSE To produce two-dimensional electrophoresis (2-DE) maps for ovine crystallins and examine changes in ovine crystallins during cataract formation. METHODS Soluble and insoluble fractions were isolated from normal, whole lenses of 26-week-old sheep, the proteins separated by 2-DE, and the spots digested with trypsin and subjected to tandem mass spectral analysis. Spot identifications wer...

Up to the present time the function and significance of the zona pellucida in the development of mammalian eggs has not been fully explained. Zona-free mouse eggs will develop in vitro from the 2-cell stage, or later, up to the blastocyst stage (Tarkowski, 1961; Mintz, 1962; Gwatkin, 1963). Single blastomeres isolated at the 2-cell (Mulnard, 1965), 4and 8-cell stage (Tarkowski & Wróblewska, 196...

Up to the present time the function and significance of the zona pellucida in the development of mammalian eggs has not been fully explained. Zona-free mouse eggs will develop in vitro from the 2-cell stage, or later, up to the blastocyst stage (Tarkowski, 1961; Mintz, 1962; Gwatkin, 1963). Single blastomeres isolated at the 2-cell (Mulnard, 1965), 4and 8-cell stage (Tarkowski & Wróblewska, 196...