Arylsulphatase activity and cerebroside sulphates in the frog oviduct during the reproductive cycle

Chromatin condensation during Scrobicularia plana spermiogenesis: a controlled and comparative enzymatic ultracytochemical study

In Scrobicularia plana testis, a nuclear acid phosphatase (ACPase) activity was detected in mid and late spermatids with the improved Gomori-chloride procedure. Lead deposits were first observed in mid spermatids at focal points over condensed chromatin strands, increasing in density as chromatin further condensated. In late spermiogenesis, lead deposits became concentrated between chromatin aggregates, and after total DNA compaction were transfered to the nuclear periphery and then shed into the cytoplasm. The specificity of the nuclear ACPase was tested against different pH values (3.9, 7.2, 7.8, 9.0), substrates (TPP, IDP, TMP, p-NCS, ATP, GTP, AMP, ADP, AMP-PNP) and inhibitors (NaF, levamisole, Zn, vanadate, theophylline). To further specify the nature of this nuclear ACPase, other enzymes were comparatively studied at their optimal pH values and at pH 5.0: nucleoside-diphosphatase, thiamin-pyrophosphatase, inorganic trimetaphosphatase, lysosomal arylsulfatases A and B, ATPase, GTPase, 5'-nucleotidase, adenylate kinase, and adenylate cyclase. Several other controls were introduced to exclude artefactual deposits induced by lead ions and tissue molecules. The results showed that the enzyme has an optimal pH at 5.0, a high specific affinity for beta-GP, and is inhibited by NaF, which suggests that it behaves as a type B-ACPase, and all controls demonstrated the specificity of the enzymic activity. Because lead deposits were specifically and temporally associated with spermatid chromatin condensation, when DNA and RNA synthesis, histones, phosphoproteins and RNA molecules strongly decrease, it is possible to suggest that the nuclear ACPase could be associated with DNA processing during chromatin compaction or involved in the hydrolysis of 2' and 3' nucleotides resulting from nuclear RNase action during RNA degradation.

Arylsulphatase A activity and sulphatide concentration in the female rabbit oviduct are under physiological hormonal influence

Oviduct samples of female rabbits in different phases of the reproductive cycle were analysed to establish the role of sex steroid hormones in the regulation of sulphatide concentration and arylsulphatase A activity. In addition to biochemical procedures, histochemical techniques were used to localize both enzyme activity and the natural substrate. The plasma concentrations of progesterone and 17 beta-oestradiol were determined by radioimmunoassay (RIA). The findings show that the parameters examined undergo considerable changes during the different phases of the reproductive cycle. Oestrogens exert an inducing action on arylsulphatase A activity, while progesterone inhibits it. Fluctuations of the catabolic arylsulphatase activity condition the sulphatide concentration, which reaches maximum values at the eighth post-ovulatory day when progesterone dominance is consolidated. In this phase of the reproductive cycle, thin-layer chromatography confirms the presence not only of larger quantities of sulphatides, but also of all other lipid fractions.

Changes induced by progesterone treatment in the sulphatides of the frog oviduct

Sulphatides have been studied by histochemical and biochemical procedures in the oviduct of the frog in different experimental conditions. In ovariectomized or hypophysectomized animals, compared to sham-operated, an increase in sulphatides was observed. The progesterone treatment did not significantly modify this lipid fraction in ovariectomized frogs, while in hypophysectomized frogs it induced a further increase. Densitographic profiles of the sulphatides, obtained by thin-layer chromatography (TLC) and also recorded by Tesak equipment, were similar in ovariectomized or hypophysectomized frogs following hormone treatment because they showed three distinct fractions in both experimental groups of animals. The appearance of a third fraction never previously observed was probably induced by the progesterone treatment. Moreover, under the effects of this hormone, the phospholipid fractions (phosphatidylcholine and phosphatidylethanolamine) also showed different densitographic profiles.

Sialic acid and neuraminidase activity in the frog oviduct: comparative biochemical investigation in the different tracts during the reproductive cycle

1. A biochemical study was carried out on the protein-bound and lipid-bound sialic acid, and neuraminidase activity in the different tracts of the oviduct of the frog Rana esculenta during the reproductive cycle. 2. Plasma sexual steroids were also investigated by RIA. 3. Fluctuations in neuraminidase activity are related to that of glycoprotein sialic acid and plasma estradiol. Glycolipid sialic acid does not have a close relationship either with neuraminidase or plasma estradiol. 4. Very high plasma concentration of progesterone before ovulation and, on the contrary, its drop after ovulation were observed. 5. The results are discussed and hypotheses advanced to explain fluctuations of the studied parameters during the reproductive cycle.

Arylsulphatase activity in the oviduct of the frog Rana esculenta. II. Progesterone-induced changes following ovariectomy and hypophysectomy

The effects of progesterone treatment on arylsulphatase activity were studied histochemically and biochemically in the frog oviduct under different experimental conditions. In ovariectomized animals, the hormone induced a large increase in enzyme activity, while in hypophysectomized ones there was a large decrease in this activity. These results indicate that the facilitatory and inhibitory effects of progesterone on arylsulphatase activity are influenced by the presence in situ of the gonad. Hypotheses are advanced to explain different effects of the progesterone treatment.

Arylsulphatase activity in the oviduct of the frog Rana esculenta. I. Oestradiol-induced changes following ovariectomy and hypophysectomy

The effects of oestradiol treatment on arylsulphatase activity in the frog oviduct are reported. Oestradiol-induced changes were also investigated in ovariectomized and hypophysectomized animals. Under all the experimental conditions, hormonal treatment causes an increase in enzyme activity. This can be observed biochemically and also histochemically on frozen sections. Hypotheses are advanced to explain fluctuations in arylsulphatase activity.