Changes in brush-border enzyme activities of intestinal epithelial cells isolated from the villus-crypt axis during the early phase of alloxan diabetes in rats

The sucrase activity in enterocytes isolated from the villus crypt axis was found to increase in all regions of the villus from day 2 after induction of diabetes, and the increase continued until day 4. In contrast, alkaline phosphatase activity increased mainly in the apical one-third of the villus-crypt column, and the increase occurred abruptly on day 4 with increase in food intake.     

Changes in brush-border enzyme activities of intestinal epithelial cells isolated from the villus-crypt axis during the early phase of alloxan diabetes in rats

Summary The sucrase activity in enterocytes isolated from the villus crypt axis was found to increase in all regions of the villus from day 2 after induction of diabetes, and the increase continued until day 4. In contrast, alkaline phosphatase activity increased mainly in the apical one-third of the villus-crypt column, and the increase occurred abruptly on day 4 with increase in food intake.     

Changes in the protein kinase C activity or rat sternomastoid muscle during development and after denervation

Summary The relationship between the activity of protein kinase C (PKC) and muscle innervation was explored in the rat sternomastoid muscle (SM) from day 18 of gestation (E18) to adult age. Between E18 and birth, PKC activity rose 5-fold, and during the day after birth, diminished to a level characteristic of the mature muscle. The rise chiefly occurred in the neural part of the muscle, in both the membrane and the cytosol fractions. Between E18 and day 5 after birth, the ratios of membrane to cytosol PKC activity rose from 0.5 to 10 and 3 respectively in the neural and aneural parts of the muscle. Denervation of adult SM reduced PKC activity by half in the membrane fraction of the neural part but did not significantly change it in the membrane or cytosol fractions of the aneural parts. These results suggest that innervation plays an important part in determining the level of PKC activity in muscle.     

Changes in the protein kinase C activity or rat sternomastoid muscle during development and after denervation

The relationship between the activity of protein kinase C (PKC) and muscle innervation was explored in the rat sternomastoid muscle (SM) from day 18 of gestation (E18) to adult age. Between E18 and birth, PKC activity rose 5-fold, and during the day after birth, diminished to a level characteristic of the mature muscle. The rise chiefly occurred in the neural part of the muscle, in both the membrane and the cytosol fractions. Between E18 and day 5 after birth, the ratios of membrane to cytosol PKC activity rose from 0.5 to 10 and 3 respectively in the neural and aneural parts of the muscle. Denervation of adult SM reduced PKC activity by half in the membrane fraction of the neural part but did not significantly change it in the membrane or cytosol fractions of the aneural parts. These results suggest that innervation plays an important part in determining the level of PKC activity in muscle.     

Interaction of glucocorticosteroids with glucagon in the control of argininosuccinase activity in the fetal rat liver]

Exogenous glucagon, but not glucocorticosteroids cause a rise in argininosuccinase activity in the liver of 21.5 day old fetuses. When fetuses are deprived of glucocorticosteroids, glucagon is unable to promote the enzymic activity. This study indicates that glucocorticosteroids are required for the induction of the argininosuccinase activity by glucagon.     

Effects of cortisone and thyroxine on intestinal trehalase activity in infant mouse.

Cortisone acetate (25 microgram/g b.wt/day) administration to 8-day-old suckling mice induces a premature increase of trehalase activity along the entire small intestine. On the other hand, thyroxine (1 microgram/g b.wt/day) in unable to provoke a precocious increase of trehalase activity. Trehalase appears to be the only brush border membrane disaccharidase controlled solely by glucocorticoid hormones during the postnatal maturation of the intestine.     

Activity of phospholipases A and some lysosomal enzymes in rat testes at different stages of hypervitaminosis A

Summary Excess of vitamin A induces decrease of neutral phospholipase A₁ and A₂ activity in rat testes homogenates on the 4th day, and increase of -galactosidase activity on the 8th day of treatment. It is suggested that phospholipase A activity decrease is of great importance in development of testicular disorders, caused by disbalance of vitamin A.     

Glutathione peroxidase in erythrocytes and plasma of rats during pregnancy and lactation

Summary The glutathione peroxidase activity in the plasma of rats on the 20th day of pregnancy was found to be 50% lower than in nulliparous control animals. During lactation, the level rose again but was still significantly different from that of the control rats on the 20th day post partum. The erythrocyte enzyme activity remained unchanged.Acknowledgments. We should like to thank Dr A. Wendel, Physiologisches Institut der Universität Tübingen, for his advice on carrying out the glutathione peroxidase assay.     

In vivo effect of sodium valproate on mouse liver

The in vivo effect of sodium valproate (SV) on the activity of uridine diphosphate glucuronosyltransferase (UDP-GT) and hepatotoxicity in the mouse liver was studied. Mice were injected intraperitoneally (IP) with SV at doses varying from 50 to 800 mg/kg per day, for six consecutive days (dose-response group) or at a standard dose of 300 mg/g per day for 2-10 days (time-response group), whereas the controls were injected with normal saline. Valproic acid levels had a positive correlation to the dose (P < 0.001) and duration of drug administration (P = 0.006). A gradual increase in UDP-GT activity was observed in doses of up to approximately 400 mg/kg per day, whereas in higher doses the enzyme activity gradually decreased. The time course of UDP-GT activity at the standard dose of 300 mg/kg per day increased progressively, with a maximum up to the sixth day and then had a gradual reduction. Hepatic necrosis (which was unrelated to the dose or the duration of drug administration) was found in 13% of the SV-treated animals and in none of the controls. We conclude that at an optimal dose (300-400 mg/kg per day) and at a time course of 6 days, SV causes liver UDP-GT induction, whereas in higher doses and longer duration of administration, UDP-GT activity is gradually reduced. SV also causes hepatotoxicity unrelated to dose and time course.     

Juvenile hormone degradation in brain and corpora cardiaca-corpora allata complex during the last larval instar ofGalleria mellonela (Lepidoptera,Pyralidae)

Summary Time course analysis of juvenile hormone degradation in the brain and the corpora cardiaca-corpora allata complex shows that during the first two days of the last larval instar the juvenile hormone degradation is very low. Starting from the third day up to the seventh day a continuous increase of esterase activity is observed.     

Ontogenesis of monoamine oxidase in the thyroid gland of rats

Summary During postnatal development, MAO activity in the thyroid gland of male rats increases until day 16, when adult values are reached.     

Changes in the distribution of gamma-glutamyl transferase in the organs of the mouse as a function of development]

In the Mouse, gamma-glutamyl transferase distribution changes with development in the kidney and the liver; on the contrary, its activity remains almost equal and low in other organs. In the liver, a low activity is observed in the fetus and the new-born up to the 3rd day of life; then it is no more measurable. In the kidney, the low enzyme activity of the fetus is multiplied by 10 in the 10 first days of life and by 50 in the 6 first weeks.     

Cholesterol 7alpha-hydroxylase activity of the rat liver after hypophysectomy and administration of hypophyseal hormones (author's transl)]

In order to elucidate the role of the hypophysis in the regulation of cholesterol 7alpha-hydroxylase activity, male and female rats hypophysectomized on day 50 of life were treated with different hypophyseal hormones and tested on day 85 of life. Only a crude extract from human hypophysis and ovine prolactin was able to enhance the enzyme activity, thereby restoring the level of intact controls.     

The action of D-penicillamine on cytochrome oxidase in vivo and in vitro

Summary The activity of cytochrome oxidase greatly decreases in the organs of rats treated with D-penicillamine for 20 days (30 mg/100 g/day). Although the drug does not affect cytochrome oxidase in vitro, it readily reduces oxidized cyt. c.     

Effect of progesterone on male and female sex behavior induced by steroid hormones in adult ovariectomized ewes]

Ovariectomized adult Ewes daily treated with I/M injections of testosterone propionate (10 mg/day) or oestradiol benzoate (200 microgram/day) show male-like sexual behaviour and simultaneously a permanent female receptivity. Additional daily treatment with 100 mg of progresterone results in a rapid decrease in male sexual responses both when Ewes are treated with testosterone and with oestradiol. No effect is observed on the female receptivity. Cyproterone acetate (100 mg/day) given to Ewes in addition to daily injection of testosterone propionate (10 mg/day) has effects similar to those of progesterone. These results show that progesterone has antiandrogen and antioestrogen properties and that this hormone administered at high doses is able to inhibit male activity.     

Angiotensin I converting enzyme activity in pulmonary tissue of fetal and newborn rabbits

Summary Angiotensin I converting enzyme in pulmonary tissue of fetal and newborn rabbits was measured using Hip-His-Leu as substrate. Enzyme activity was detected in the late fetal period, increased gradually until birth and increased markedly after birth. Enzyme activity reached adult levels on the 2nd and 3rd day after birth. This observations suggests that the metabolic activity of the lung for angiotensin develops suddenly at the time of derivery.This work was supported in part by grant No. 187032 from Ministry of Education.     

Rhythmicity of aminotransferase in the cockroach,Periplaneta americana

Summary Aspartate (AAT) and alanine aminotransferase (AIAT) activities in nervous system and coxal leg muscle of the cockroach showed circadian variations with maximal activity around midnight, alternating with minimal activity at 12.00 noon of the solar day. The enhanced activity levels of the enzymes observed during night dark hours may be related to higher energy requirements during increased locomotor activity of the animals.We thank Prof. K. S. Swami, for providing facilities. The financial help rendered by UGC and CSIR, in the form of Junior (to SV) and Senior (to TPK) Research Fellowships is acknowledged.     

Mitotic activity in the rat palatal shelves during their fusion in vitro]

Rat palatal shelves explanted on gestational day 15 or 16 are cultivated with their medial-edge epithelial surface in contact. Observations of histological sections showed that, before and during the fusion of the processes, mitotic activity is always lower in the epithelium of the expected fusion zone (EFZ) than in the oral epithelium and progressively decreases during the processus of the fusion.     

Die Veränderungen der Succinodehydrase-Aktivität in Detroit-6 (VA) Zellen,infolge der Infektion mit demHepatitis-infectiosa-Virus

Summary The inhibitory action ofHepatitis infectiosa virus on the SDH activity of Detroit-6 (VA) cell lines was investigated. The full inhibition of the SDH activity took place at the end of the third day after the infection. As this phenomenon precedes the cytopathogenetic effect of viral infection, it may be of some help in the early detection of the infection.     

Effect of Corynebacterium parvum on serum lysozyme (muramidase) levels (author's transl)]

An i.v. injection of 548 microgram of killed Corynebacterium parvum into C57B1 mice leads to significant changes in serum lysozyme (muramidase) levels. After an initial fall at 24 h, the activity of the enzyme increased progressively, reached a peak on the 9th day and returned to control range after the 15th day.