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

Summary 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 presencein 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

Summary 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.     

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

Summary The presence of arylsulphatase A and cerebroside sulphates in different tracts ofRana esculenta oviduct during different phases of the reproductive cycle were investigated by histochemical and biochemical procedures. The results indicate that enzyme activity shows seasonal fluctuations connected with the phase of the sexual cycle. The concentrations of cerebroside sulphates (the natural substrates of arylsulphatase A) is related to the activity of this hydrolytic enzyme. The role of arylsulphatase A activity in regulating the substrate concentration, and particularly that of sulphatides, is discussed.     

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

Summary 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 17β-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.     

Compositional changes in the rat femur following ovariectomy

Ovariectomy has been shown to produce osteoporosis in the femur of the rat. 11-month-old Sprague-Dawley rats were either ovariectomized or given a sham operation. The loss of calcium in the femur of the rats was compared with two indices of osteoporosis, the ponderal index and the femur score. The calcium content was more closely associated with the femur score (r = 0.5, p = 0.0064) than with the ponderal index (r = -0.367, p = 0.05). An accelerated rate of fat deposition in the ovariectomized rat femur reduced the femur weight loss, which resulted in a barely significant association of calcium content with the ponderal index.     

Segmental distribution and gestational changes of GABA-transaminase activity in the rat oviduct

The occurrence and the localization of 4-aminobutyrate:2-oxoglutarate transaminase (GABA-transaminase) in the non-pregnant and pregnant rat oviduct were examined using biochemical and enzyme histochemical techniques. Specific GABA-transaminase activity was detected in the ampullary and isthmic portions of the oviduct as well as in the utero-tubal junction. The enzymic activity was lower in the ampullary than in the isthmic or intramural segments of the oviduct. Pregnancy induced a significant increase of GABA-transaminase activity in each portion of the oviduct. Enzyme histochemistry showed the highest GABA-transaminase reactivity at the level of the epithelial cells of the oviduct irrespective of the portion of the tube examined. A faint specific activity was demonstrated in the smooth muscle of the oviduct while the serosa did not show specific staining. Our findings indicate that: the observed increase of GABA-transaminase activity in the oviduct of the pregnant rat may be responsible for the reduced GABA levels in the oviduct during gestation; and the extraneuronal localization of GABA-transaminase activity does not seem to support the suggestion of a possible GABAergic innervation of the oviduct.     

Morphofunctional changes in the insular apparatus of the pancreas following hypophysectomy and administration of somatotropic hormone]

Mature white male rats were used to study effects of hypophysectomy and STH on sugar content after fasting and after reiterated glucose loading. Morphological and morphometrical investigation of the pancreatic endocrine tissue were made. Zinc content and distribution in the pancreas, as well as aldehydefuchsinophil granulation in B-cells of the islets of Langergans were studied. Hypophysectomy was stated to increase functional activity of the pancreatic insular apparatus. Injection of STH for 9 days resulted in the stimulation of the cells in the insular apparatus. Prolonged injection of STH (for 20 days) produced exhaustion of the pancreatic insular apparatus.