Changes in the activities of jejunal glucosidases in experimental intestinal tumorigenesis induced by 1,2 dimethylhydrazine in rats fed different diets.

The purpose of the present study was to establish the effect of the carcinogen 1,2 dimethylhydrazine on the activities of the jejunal glucosidases and to assess the possible modifying effect of different diets. Two control groups of Wistar albino rats were used - fed standard pellet diet and fed the same diet + 1,2 dimethylhydrazine treatment. Six experimental groups treated with 1,2 dimethylhydrazine were provided. One of them was fed standard diet, containing 30% of wheaten bran and the other 5 groups received high-lipid diets, containing 30% of different fats. The rats were injected subcutaneously once a week for 12 weeks with 20 mg 1,2 dimethylhydrazine/kg b.m. and left for 12 weeks in order to develop a tumor growth. The activities of 5 glucosidases (lactase, maltase, sucrase, palatinase and cellobiase) were determined in homogenates from jejunal mucosa taken near by the tumors and in homogenates from the tumors themselves. An expressed decrease of the jejunal glucosidase activities near the tumors and in the tumors was established. The animals fed 30% wheaten bran diet did not develop tumorigenesis and showed comparatively slight decrease of the enzyme activities. In general, the high-fat regimens did not exert such a preventive effect.

The effect of thioacetamide on rat liver plasma membrane enzymes and its potentiation by fasting.

Thioacetamide, given intraperitoneally (1.4 mmol/kg body mass) to male Wistar rats 24 h before sacrifice promoted a marked elevation of serum aminotransferases, loss of microsomal cytochrome P-450 content and a significant reduction (about 50%) of the liver plasma membrane enzymatic activities (5'-nucleotidase; K+, Na+- and Mg2+-adenosine triphosphatases; and gamma-glutamyl transferase). Previous starvation for 48 h, immediately prior to thioacetamide administration, strongly potentiated the effects of thioacetamide on the serum, microsomal and liver plasma membrane parameters, while fasting itself did not affect them. The liver plasma membrane damage may be one of the reasons for the cell death in thioacetamide-intoxicated rat livers.

Changes in some intestinal enzyme activities in experimental hexachlorobenzene-induced porphyria and modifying effects of diet.

Some diets exert a considerable influence on porphyrin metabolism and induction of microsomal liver enzymes in experimental porphyria induced by hexachlorobenzene (HCB). As HCB and its metabolites come into direct contact with intestinal mucosa, this study investigated the changes in the activities of intestinal disaccharidases and gamma-glutamyl transferase in a model of HCB-induced porphyria. The effects of different diets on enzymatic activities during HCB intoxication were also studied. HCB was administered by gastric tube at 3.5 mmol/kg body weight daily for 90 and 61 days. HCB intoxication strongly diminished the activities of intestinal lactase, maltase, sucrase, cellobiase and trechalase. Carbohydrate diets (with 78 weight % glucose or starch), given simultaneously with HCB treatment, exerted a protective effect on disaccharidase activities. These regimens maintained cellobiase and trechalase within the normal levels and even increased maltase. High-fat/high-protein diets (with 30% either butter or sunflower oil and 31% casein) aggravated the decrease of all disaccharidases. In contrast with the decrease in disaccharidase activity, intestinal gamma-glutamyl transferase was increased, suggesting multiple mechanisms for the action of HCB intoxication on the intestinal enzyme system. Diet had a pronounced modifying effect.

[Small intestine perfusion. The authors' own method for the simultaneous performance of biopsy and perfusion of the human small intestine]. / Tunkochrevna perfuziia. Sobstven metod za ednovremenno izvurshvane na biopsiia i perfuziia na tunko chervo pri khora.

The analysis of advantages and disadvantages of the technique and principles of the methods of small intestinal perfusion, used by various authors in the studies on resorption processes, provided grounds the authors to develop their own method. The system for infusion and aspiration by a combined probe is described. Details about the composition of perfusion solution, the technique of the study and calculation of resorption rate are reported. The advantages of the method are as follows: simultaneous performance of small intestinal glucose perfusion and biopsy of small intestine, good tolerance by the patients and availability of the elements needed for the construction of the probe and system for infusion and aspiration. The mean glucose resorption rate was 814,07 mumol/min/30 cm in 9 subjects with no small intestinal diseases and with normal histomorphological picture of small intestinal mucosa.

[Parallel morphological and functional research on chronic enterocolitis patients using the authors' own method for the simultaneous performance of perfusion and biopsy of the small intestine]. / Paralelni morfologichni i funktsionalni izsledvaniia pri bolni s khronichen enterokolit s pomoshtta na sobstven metod za ednovremenno izvurshvane na perfuziia i biopsiia na tunko chervo.

Thirty two patients were studied with chronic enterocolitis and 9 patients without any small intestinal diseases, with normal histomorphological picture of small intestinal mucosa--control group. The method of simultaneous performance of perfusion and biopsy of small intestine was used. Glucose resorption rate in small intestine was studied and histomorphological, electron--microscopic and enzymologic (disaccharidases) studies were carried out on jejunal mucosa. Data about chronic enterocolitis without atrophy were established in 17 patients, in 10--initial partial atrophy, in 5--advanced partial and subtotal atrophy of jejunal mucosa. Reduced glucose resorption rate was established in small intestine in the patients with chronic enterocolitis as compared with that of the control group. Glucose resorption rate correlates with the severity of the histomorphological changes in small intestinal mucosa. Disturbed resorption rate was established via jejuno--perfusion in patients with clinically not manifested syndrome of malresorption and absence of histomorphological changes in small intestinal mucosa, but with established ultrastructural changes in enterocytes.

[Changes in the histamine content and morphology of the gastric mucosa in duodenal ulcer after pentagastrin stimulation]. / Promeni v khistaminovoto sudurzhanie i morfologiiata na stomashnata ligavitsa pri duodenalna iazva sled stimulatsiia s pentagastrin.

A parallel study on histamine concentration and morphology of biopsy from gastric mucosa, was carried out with 60 patients with duodenal ulcer, prior to and post stimulation with pentagastrin--6 micrograms/kg. Histamine was spectrofluorimetrically determined. The functional-morphological changes that developed were followed up on 15, 30 and 60 min after the stimulation. They were a functional character and were due to disturbed microcirculation of the gastric mucosa: edema, venous stasis and leukopedesis. The latter were progressively increased within the course of 1 hour after the stimulation. The histamine-mobilizing effect of pentagastrin was manifested with a short-term decrease, followed by a considerable increase of histamine content in gastric mucosa of the patients with duodenal ulcer.

[Gluten enteropathy--epidemiologic, clinical, morphologic and enzymatic study]. / Glutenova enteropatiia--epidemiologichno, klinichno, morfologichna i enzimno prouchvane.

The results from the clinical, morphological and enzymatic studies are reported upon the jejunal mucosa and the effect of a gluten-free diet among a group of 60 patients with gluten enteropathy and 5 patients with idiopathic steatorrhea. The significance of light microscopic and electronmicroscopic studies are discussed in details in making the diagnosis, differential diagnosis and assessment of the results from the treatment of gluten enteropathy.

[Galactorrhea and prolactin secretion in acromegaly]. / Laktoreia i sekretsiia prolaktina pri akromegalii.

Dependence of lactorrhea on the basic blood level of somatotropic hormone (STH), prolactin (PL), folliculostimulating hormone (FSH), and luteinizing hormone (LH) was studied in 62 patients with an active phase of acromegaly, untreated, and in 41 with inactive phase of the disease following radiation therapy. Thyrotropic hormone (TTH), PL, and STH secretion (basic and after intravenous injection of 200 micrograms of thyroliberin) was determined in 20 patients with active and in 6--with inactive acromegaly following radiation therapy. In patients with active acromegaly the percentage of lactorrhea in women constituted 60 and in men--9.5, and with inactive acromegaly (after radiation therapy) it was 13.3 and 0, respectively. Basic PL level was significantly elevated in both groups of patients. The principle role in the pathologenesis of lactorrhea in acromegaly proved to be played by increased PL secretion. Under the effect of thyroliberin PL secretion was significantly elevated in comparison with control in 15 patients with active acromegaly and in all cases at the stage of remission. Basic TTH level and this level after thyroliberlin stimulation was within the normal range. In 4 patients with lactorrhea the absence of TTH secretion was combined with unresponsiveness of PL secretion, this suggesting the presence of tumour growth. STH secretion was independent of lactorrhea both under basic conditions and after thyroliberin stimulation.

Effect of the pesticides phosalone and lindane on the activity of some dipeptidases and disaccharidases in rat intestinal mucosa.

The intestinal dipeptidase and disaccharidase activities were investigated in 120 male albino rats of the Wistar strain after administration of 21 mumol.kg-1 body weight phosalone, 14.8 mumol.kg-1 body weight lindane and 10.5 mumol.kg-1 body weight phosalone combined with 7.4 mumol.kg-1 body weight lindane. The dipeptidase activity under the effect of these comparatively low doses of pesticides reveals slightly to moderate changes. The activity of intestinal disaccharidases after a 90-day phosalone and lindane treatment is markedly decreased, particularly that of sucrase. The mechanism of these changes remains unknown.

Developmental studies on gamma-glutamyl transferase in rat intestinal mucosa.

The activity of gamma-GT in rat intestinal mucosa has been studied during normal development. No significant differences in enzymatic activity have been recorded between 21-day-old fetuses, neonates tested at 3, 10, 20 and 30 days and older animals (65 days). Only in the period immediately prior to birth did the liver gamma-GT display activity levels similar to those of intestinal gamma-GT. In neonates and in adult rats, the intestinal gamma-GT activity was much higher as compared to the enzymatic activity in the liver, possibly revealing a species feature in rats. The results of the studies show that the rat is particularly suitable for experimental studies on intestinal gamma-GT in pathological conditions.

[The functional state of the hypothalamo-hypophyseal system in tumors of the pituitary and diencephalic area]. / Funktsional'noe sostoianie gipotalamo-gipofizarnoi sistemy pri opukholiakh gipofiza i dientsefal'noi oblasti

A study was made of 38 persons, including 25--with acromegaly, 5--with chromophobic adenomas of the hypophysis, 3--with diencephalic tumours and 5 healthy individuals. STH, TTH and ACTH were determined in the blood plasma with the aid of radioimmunological methods under basic conditions and L-DOPA loading (10 mg per 1 kg of weight) with insulin (0.10 U/kg). There was an increase in the plasma content of STH, TTH and ACTH with a maximum 60 min after the administration of L-DOPA. In the patients with acromegaly STH increased considerably, and in cases with chromophobic adenomas and diencephalic tumours--less. ACTH level was also elevated. STH and ACTH level rose after insulin hypoglycemia. Possible mechanisms of a stimulating action of L-DOPA and insulin are discussed.