Mast cell-Leydig cell relationships in the testis of the lizard Podarcis s. sicula Raf: thermal manipulation, ethane 1,2-dimethane sulphonate (EDS) and sex hormone treatment.

Mast cells of connective tissue type are scattered in the interstitial compartment of the lizard Podarcis s. sicula. Their number varies during the year, showing peaks in spring and in winter, respectively. Thermal manipulation affects mast cell number (MCN): high temperature decreased MCN in both January and May, while low temperature increased MCN only in January. Ethane dimethane sulphonate, a toxin which specifically destroys Leydig cells, induced an increase in MCN on days 3 and 7 of treatment. Oestradiol treatment provoked a strong increase in MCN that was blocked by tamoxifen. Blocking androgen receptors with cyproterone acetate resulted in an increase in MCN, while testosterone injection provoked a strong decrease. These results suggest a relationship between the presence of mature Leydig cells and mast cell proliferation and/or differentiation.

Ethane 1,2-dimethane sulfonate effects on the testis of the lizard, Podarcis s. sicula Raf: morphological and hormonal changes.

Ethane 1,2-dimethane sulfonate (EDS) destroys Leydig cells in the testis of some rodents (mice excluded), disrupts interstitial and germinal compartments in the frog, Rana esculenta, while it stimulates testicular activity in the teleost, Gobius paganellus. In the Japanese quail the toxin removes mature spermatozoa. There is no information on EDS effects in reptiles. The present study examines the effect of EDS treatment in the lizard Podarcis s. sicula Raf during two different periods of the testicular cycle (winter stasis and breeding season). Animals received a single EDS injection (100 mg/kg body wt) and were sacrificed at 0 and 24 hr and 3, 5, 7, 11, and 28 days after injection. Androgens were measured in plasma and right testes, while left testes were examined histologically. Plasma androgen levels decreased 5-7 days after EDS injection, alongside interstitial tissue destruction and mast cell appearance, with slight but significant increases on Days 11 and 28. Testicular androgen levels did not change. On Day 11 metaphases were present in the interstitial tissue which regenerated on Day 28. Between Days 5 and 7 some pycnotic nuclei of spermatocytes appeared, mitotic activity of spermatogonia was normal, but germ cell stages were disorganized and empty spaces appeared at the boundary of the tubule. These data show that a single EDS injection results in destruction and repopulation of the interstitial cells in a reptile. Moreover, the effects of EDS in the lizard suggest that P. s. sicula Raf testis responds to the toxin in a similar fashion to the rat testis.

Mallory stain may indicate differential rates of RNA synthesis: I. A seasonal cycle in the harderian gland of the green frog (Rana esculenta).

When Mallory's trichrome stain is used, acinar nuclei of the Harderian gland of Rana esculenta display different affinities for the dye. Some of the orangiophilic nuclei show affinity for aniline blue (blue nuclei). In the Harderian gland of Rana esculenta their number and the intensity of staining with aniline blue may vary during the year. The affinity for aniline blue disappears following digestion of paraffin sections with RNAase, but not with DNAase or trypsin. Furthermore, in vitro incubation with [5, 6-3H]-Uridine shows a selective incorporation by the majority of blue nuclei. Therefore, the affinity for aniline blue is likely due to increased RNA synthesis. The increment of nuclear RNA shown by these methods is supported by the quantitative determination of total RNAs during the resumption (October) and enhancement (May) of secretory activity, when the percentage of blue nuclei of the acinar cells is at its highest levels of the year. The affinity of RNA-rich nuclei for aniline blue, while others are strictly orangiophil, is discussed on the basis of molecular structure of the dyes used in the staining mixture. Mallory's trichrome stain appears to be an useful tool for detecting changes in cell nuclear status.

Mallory stain may indicate differential rates of RNA synthesis: II. Comparative observations in vertebrate nuclei.

The differential staining of nuclei by the use of the Mallory trichrome method was investigated in a variety of tissues of representative vertebrates. By this method nuclei stained orange or blue; erythrocyte nuclei stained red. Since the higher affinity for aniline blue is due to an increased RNA synthesis, it was possible to reveal not only the changing metabolic status of a cell type, as shown for instance in the liver parenchyma and other glandular tissues, and nervous tissue, but also in different cell populations in the same tissue, such as the spleen.

Number of mast cells in the harderian gland of the green frog, Rana esculenta: the annual cycle and its relation to environmental and hormonal factors.

The Harderian gland of the green frog contains mast cells. Their number shows annual variations, being more numerous in the winter months. The increase of mast cell number (MCN) is matched by a marked degranulation. No sex differences are found throughout the year. Manipulations of the photoperiod and temperature, either in winter or in summer, suggest that only the latter is responsible for the annual variations. Exposure to higher temperatures causes a decrease in the MCN in the winter frogs, while exposure of the summer frogs to low temperatures provokes the opposite effect. The pituitary gland also influences MCN. Hypophysectomy causes a decrease of MCN, with a return to normal following replacement therapy with homologous pars distalis homogenate. Among pituitary hormones, only ACTH mimics the effect of pars distalis homogenate. However, a possible link seems to exist between environmental (temperature) and hormonal (pituitary) factors, since hypophysectomy prevents the increase of MCN in the summer frogs exposed to low temperatures.

Influence of light and temperature on the secretory activity of the Harderian gland of the green frog, Rana esculenta.

1. The secretory activity of the Harderian gland in Rana esculenta varies during the year, reaching its highest activity during the hottest period (July-August). Therefore, secretion may be modulated by temperature and/or photoperiod. 2. Adult males and females were placed under several combinations of light and temperature in two different periods of the year (February and July) in order to elucidate their respective roles, if any, on the stimulation of secretion. 3. Under experimental conditions, high temperature (24 degrees C), irrespective of the photoperiod selected, stimulates secretion shown both at histological and histochemical levels. 4. Low temperature (8 degrees C) impairs secretory activity, again independently of the photoperiod selected. 5. This data suggests that the secretion of the Harderian gland in Rana esculenta is modulated mainly by temperature.