Foods found in the wild around nuclear sites: an evaluation of radiological impact.

Habit surveys were carried out around four licensed nuclear sites to identify people who collect foodstuffs from the wild (so-called 'free foods'). In total, around 800 collectors were readily identified, most of whom collected more than one free food. The data indicated that estimates of higher than average doses could reasonably be based on the three foodstuffs of most importance. Foods were selected for further study on the basis of either the number of collectors or the amount consumed. The radionuclides of interest were identified using published information on the discharges from each site. The resultant average and higher than average doses were estimated using the site-specific habit data. For all sites, doses from the consumption of free foods were low and of no radiological importance. Assessments based solely on data for cultivated foods would not therefore have underestimated radiological impact significantly. However, given the wide utilisation of free foods found in this study, for rigorous assessments it would be prudent to take account of the consumption of foods from the wild.

Histological studies of changes in the magnum of the domestic hen associated with the production of 'watery white' eggs.

Abnormalities in the magnum of hens producing eggs with 'watery whites' are described. The histological staining characteristics of the epithelium were altered and there was a decrease in the number of ciliated cells. The structure of the tubular gland cells was also changed, with an increase in the number of type-B cells.

Detection of gonadotrophic hormones on isolated thecal interstitial cells of the domestic hen, Gallus domesticus, by an immunohistochemical method.

An immunohistochemical method was used to demonstrate the presence of gonadotrophins in isolated ovarian interstitial cells. The cells were obtained by collagenase digestion of large ovarian follicles after removal of the yolk and the granulosa layer. Using a peroxidase-labelled anti-rabbit serum with anti-chicken follicle stimulating hormone (FSH) serum raised in rabbits, a strong positive reaction was obtained. Anti-human FSH serum also produced a positive result but the reaction was weaker. There was no apparent difference in the staining reaction of cells which had been preincubated with ovine FSH serum. Treatment with anti-ovine luteinizing hormone (LH) resulted in a faintly positive reaction. The viability of the cells was tested by the Trypan Blue method and they were identified as steroid-producing cells by the histochemical demonstration of their 3 beta-hydroxysteroid dehydrogenase activity.

Detection of gonadotrophic hormones on isolated granulosa cells of the domestic hen, Gallus domesticus, by an immunohistochemical method.

Two immunohistochemical methods were used to detect the presence of luteinizing hormone (LH) on the cells of chicken granulosa. Using a peroxidase-labelled anti-rabbit serum together with anti-chicken LH serum raised in rabbits, a strong positive response was obtained with granulosa cells from small and large pre-ovulatory follicles obtained from the mid-cycle. Similarly, by using an available antiserum to human follicle stimulating hormone (FSH), a slightly weaker response was obtained with cells from both large and small follicles. After incubating cells with ovine LH, ovine FSH and ovine prolactin, there was no detectable difference with the method used in reaction with their respective antisera to cells which had received no incubation, implying that chicken gonadotrophins were displaced only partially from their receptors by mammalian gonadotrophic hormones. Pre-incubation of the cells with human chorionic gonadotrophin gave negative results with anti-hCG serum. Using a fluorescent-labelled antibody method, similar results were obtained except that the distribution of the receptors on the granulosa cell for LH or FSH appeared to be different. With the LH, the fluorescence formed a halo around the cell in contrast to the overall fluorescence with FSH.

Effect of administering two prostaglandin synthetase inhibitors (indomethacin and aspirin) on egg production in the domestic fowl (Gallus domesticus).

The injection of 50 mg/kg bodyweight of a prostaglandin synthetase inhibitor (indomethacin) brought about a delayed oviposition time in birds of three breeds of layers, whereas the injection of 5 mg indomethacin had no effect. The daily ingestion of up to 400 mg aspirin or up to 10 mg indomethacin for three weeks, or 750 mg aspirin or 200 mg indomethacin for two weeks had no effect on egg production, oviposition time, egg-shell water conductance, oviducal prostaglandin synthetase activity or bird behaviour. Prostaglandin synthetase activity was demonstrable in both control and treated birds only in the tubular glands of the shell gland. These observations suggest that prostaglandins play a minor role in normal reproductive activity in the female domestic fowl.

Activity of ovarian delta 5-3 beta-hydroxysteroid dehydrogenase in the domestic fowl (Gallus domesticus) with respect to age.

The distribution of delta 5-3 beta-hydroxysteroid dehydrogenase was examined in the ovaries of hens aged 8--30 weeks. At all ages the interstitial cells (both thecal and stromal) gave a positive formazan reaction, but a positive reaction was not obtained in the granulosa cells of follicles less than 5 mm diameter in mature or immature birds. Since activity was restricted to follicles of larger size than this, it is concluded that steroidogenesis occurs in the granulosa cells for only the last 7--8 days of their life in the preovulatory follicle.

Steroid hormones in the postovulatory follicle of the domestic fowl (Gallus domesticus).

Progesterone, androstenedione, testosterone, oestrone and oestradiol were measured in the postovulatory follicle (POF) at various times up to 52 h after ovulation. The 3-fold decrease in progesterone, the major constituent, which occurred over the first 15--20 h resembled the changes previously described for the enzyme, 3beta-hydroxy-steroid dehydrogenase. At 1 h before ovulation the granulosa cells of the anteovulatory follicle (AOF) contained 50 times more progesterone than the POF granulosa fraction collected 2--3 h later. The thecal portion of the AOF had progesterone concentrations 5 times those of the POF theca, but the latter contained higher concentrations of androstenedione and oestrone.

Role of the granulosa cells of the postovulatory follicle of the domestic fowl in oviposition.

Surgical removal of the granulosa cells, leaving the remainder of the postovulatory follicle (POF) intact (including the thecal interstitial cells), resulted in delays of oviposition of about 19 h; similar delays were obtained when the granulosa was left in situ but was damaged by the insertion of a silicone disc into the POF. The insertion of wax balls resulted in delays of 3-4 h but the granulosa appeared to be normal. It is concluded that the integrity of the granulosa is important for normal oviposition.

Activity of 3beta-hydroxyteroid dehydrogenase in the postovulatory follicle of the domestic fowl (Gallus domesticus).

The activity of delta5-3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the postovulatory follicle (POF) of the domestic hen was studied; it declined rapidly during the first 15 h after ovulation and then fell gradually until 52 h when there was no detectable activity. Comparison of 3beta-HSD and glucose 6-phosphate dehydrogenase activities in the theca and granulosa cells indicated that the changes in enzymatic activity can be attributed to the thecal component; the enzyme activity in granulosa cells was stable up to 35 h after ovulation. The results appear consistent with the hypothesis that the POF is a source of steroid hormones.