Plasma steroid and corticosteroid levels in female pacu Piaractus mesopotamicus, Teleostei-Characidae.

We report the plasma levels of estradiol-17 beta (E2), testosterone (T), 17 alpha-20 beta-dihydroxy-4-pregnen-3-one (17-20P), and cortisol (F) in female pacu during the reproductive cycle (N = 44) and in females induced to ovulate with an analogue of luteinizing hormone releasing hormone (LHRHa; 10 micrograms/kg) (N = 24). The plasma hormone levels were determined by validated radioimmunoassays. Females sampled during the reproductive cycle were grouped into 4 gonadal stages: resting, early maturation, advanced maturation and regression. The calculated gonadosomatic index varied from 0.5 +/- 0.1% in resting stage to 8.1 +/- 0.6% in advanced maturation stage. The E2 and T values were highest during the early maturation stage (E2 = 2172 +/- 7.1 pg/ml; T = 412 +/- 58 pg/ml) and the F values were highest during the advanced maturation stage (132 +/- 5 ng/ml). Females induced to ovulate by LHRHa injection were sampled at 0.6, and 12 h after injection of LHRHa. Two additional groups were sampled at ovulation and 24 h after ovulation. The E2 values were highest at 6 h (2917 +/- 65 pg/ml). The T and F values were highest at ovulation (T = 3498 +/- 77 pg/ml; F = 387 +/- 16 ng/ml) and 17-20P was detected only at ovulation (2163 +/- 80 pg/ml).

Plasma steroid and corticosteroid levels in female pacu Piaractus mesopotamicus, Teleostei-Characidae

We report the plasma levels of estradiol-l7Beta (E2), testosterone (T), 17(alpha-2Obeta-dihydroxy-4-pregnen-3-one (l7-2OP), and cortisol (F) in female pacu during the reproductive cycle (N = 44) and in females induced to ovulate with an analogue of luteinizing hormone releasing hormone (LHRHa; 10 mug/kg) (N = 24). The plasma hormone levels were determined by validated radioimmunoassays. Females sampled during the reproductive cycle were grouped into 4 gonadal stages: resting, early maturation, advanced maturation and regression. The calculated gonadosomatic index varied from 0.5 ñ 0.1 per cent in resting stage to 8.1 ñ 0.6 per cent in advanced maturation stage. The E2 and T values were highest during the early maturation stage (E2 = 2172 ñ 7.1 pg/ml; T = 412 ñ 58 pg/ml) and the F values were highest during the advanced maturation stage (l32 ñ 5 ng/ml). Females induced to ovulate by LHRHa injection were sampled at 0, 6, and 12 h after injection of LHRHa. Two additional groups were sampled at ovulation and 24 h after ovulation. The E2 values were highest at 6 h (2917 + 65 pg/ml). The T and F values were highest at ovulation (T = 3498 + 77 pg/ml; F = 387 ñ 16 ng/ml) and 17-20P was detected only at vulation (2163 ñ 80 pg/ml).

Effect of aging on the glutaminase activity of neoplastic and immune tissues.

1. The effect of age and Walker 256 tumor on maximal phosphate-dependent glutaminase activity of rat immune tissue was determined. Glutaminase is a key enzyme in the metabolism of glutamine, an important fuel for normal and neoplastic cells. 2. Maximal activity of phosphate-dependent glutaminase was measured in immune tissues and tumors of Walker 256 tumor-bearing young (28 days old), mature (3 months old) and aged (15 months old) Wistar rats. The following tissues were examined: thymus, spleen, mesenteric lymph nodes and tumor. 3. Tumor implantation for 14 days reduced glutaminase activity in the thymus and mesenteric lymph nodes. Tumor glutaminase activity was lowest in aged rats and highest in the mature group. 4. Comparison of glutaminase activity in immune and tumor tissues suggested the flux of glutamine between these tissues in the 3 groups. Glutaminase activity was 2.8-fold higher in immune tissues in aged rats (2.58 +/- 0.35 vs 0.93 +/- 0.16 mumol min-1 g tissue wet weight-1, mean +/- SEM, 5 rats), and 1.9- (4.14 +/- 0.47 vs 8.36 +/- 1.29 mumol min-1 g tissue wet weight-1, mean +/- SEM, 5 rats) and 2.5-fold increased (2.41 +/- 0.20 vs 5.92 +/- 0.22 mumol min-1 g tissue wet weight-1, mean +/- SEM, 5 rats) in tumor tissue in the mature and young groups, respectively. These results suggest the deviation of glutamine flux from defense cells to the neoplastic tissue in tumor-bearing young and mature rats and may partially explain the slow cancer growth in elderly patients.

Possible role of the submandibular glands in the control of glucose metabolism in mouse enterocytes.

We evaluated the effect of sialadenectomy on hexokinase activity and on rates of lactate formation and of [U-14C]glucose decarboxylation in 3 cellular fractions of the small intestine epithelium from male adult mice. The surgery was carried out under ether anesthesia and a sham-operated group was used as control. Three cell fractions were obtained by shaking the inverted small intestine: 1) tip of the villus, 2) villus and 3) villus and crypt cells. Five days after sialadenectomy, hexokinase activity was reduced in fractions 1 (3.53 +/- 0.65 vs 1.98 +/- 0.25 nmol min-1 mg protein-1, expressed as mean +/- SEM for 7 mice) and 3 (5.01 +/- 0.55 vs 3.15 +/- 0.42 nmol min-1 mg protein-1, mean +/- SEM for 7 mice). After removal of the submandibular glands, the rates of lactate formation were decreased in fractions 2 (4.16 +/- 0.54 vs 2.30 +/- 0.25, mean +/- SEM for 10 and 11 mice, respectively) and 3 (1.74 +/- 0.24 vs 0.87 +/- 0.14, mean +/- SEM for 13 mice) and the rates of [U-14C] glucose decarboxylation were reduced in fraction 1 (1.14 +/- 0.12 vs 0.61 +/- 0.10, mean +/- SEM for 11 and 12 mice, respectively). We conclude that the secretion of submandibular glands plays a physiological role in the control of glucose metabolism in enterocytes.

Effect of aging on the glutaminase activity of neoplastic and immune tissues

1. The effect of age and Walker 256 tumor on maximal phosphate-dependent glutaminase activity of rat immune tissue was determined. Glutaminase is a key enzyme in the metabolism of glutamine, an important fuel for normal and neoplastic cells. 2. Maximal activity of phosphate-dependent glutaminase was measured in immune tissues and tumors of Walker 256 tumor-bearing young (28 days old), mature (3 months old) and aged (15 months old) Wistar rats. The following tissues were examined: thymus, spleen, mesenteric lymph nodes and tumor. 3. Tumor implantation for 14 days reduced glutaminase activity in the thymus and mesenteric lymph nodes. Tumor glutaminase activity was lowest in aged rats and highest in the mature group. 4. Comparison of glutaminase activity in immune and tumor tissues suggested the flux of glutamine between these tissues in the 3 groups. Glutaminase activity was 2.8-fold higher in immune tissues in aged rats (2.58 +/- 0.35 vs 0.93 +/- 0.16 mumol min-1 g tissue wet weight-1, mean +/- SEM, 5 rats), and 1.9- (4.14 +/- 0.47 vs 8.36 +/- 1.29 mumol min-1 g tissue wet weight-1, mean +/- SEM, 5 rats) and 2.5-fold increased (2.41 +/- 0.20 vs 5.92 +/- 0.22 mumol min-1 g tissue wet weight-1, mean +/- SEM, 5 rats) in tumor tissue in the mature and young groups, respectively. These results suggest the deviation of glutamine flux from defense cells to the neoplastic tissue in tumor-bearing young and mature rats and may partially explain the slow cancer growth in elderly patients

Comparative histochemistry of the mucoproteic cells of the hypophysis from Rhamdia hilarii, Hypostomus punctatus, Prochilodus scrofa and Cyprinus carpio (Teleostei). Immunohistochemical identification of the gonadotropic cells.

Adenohypophyseal cells showing positive histochemical reactions for mucosubstances were classified as type I-IV in Hypostomus (Plecostomus) punctatus (Loricariidae), Rhamdia hilarii (Pimelolidae), Prochilodus scrofa (Prochilodontidae) and Cyprinus carpio (Cyprinidae) according to cell shape, size, cytological characteristics and adenohypophyseal distribution. Cell types I and II are common to the four species, with each cell type showing very similar cytological and histochemical characteristics, in spite of different adenohypophyseal distribution of cell type II, according to the teleost species. Type I cells are globular basophils located in the proximal pars ditalis and are positive to PAS and Alcian blue pH 2.5 (AB) reactions, showing cytoplasmic vacuoles and changes in granule concentration in the mature phase of the gonadal cycle. The smaller type II cells are fusiform or oval basophils exhibiting a strong AB reaction but also reacting to PAS. Type III cells are located in the pars intermedia showing PAS-positive reaction. Considering different teleost species, these cells exhibit some variations specially in relation to cell size and shape which are not detected in mature male C. carpio. Otherwise cell type IV is only present in the rostral pars distalis of P. scrofa. They are weakly basophilic and negative to PAS, reacting strongly to AB. Only cell type I showed unequivocally positive immunohistochemical results with anti-salmon gonadotropin.

Thyroidal modulation of androgenic expression in mice submandibular gland.

We investigated the influence of testes and thyroid gland on the maintenance of biochemical parameters and of [3H]R1881 binding sites of adult mice submandibular gland (SMG). Castration (Cx) performed at beginning of puberty prevented sex-dependent SMG development without interfering with maximal androgen binding capacity. Thyroidectomy (Tx) had strong effects on SMG, mainly by lowering the number of androgen binding sites. All alterations could be fully reverted after treatment with testosterone (5 mg/animal, single dose) or with thyroxine (T4, 250 micrograms/animal per day during 5 days). The effects of Cx on SMG could be reverted by therapy with testosterone, T4, or with both hormones (testosterone + T4) in a non-synergistic fashion. It is shown the importance of thyroidal activity on the physiological maintenance of androgen receptors in the murine SMG; the role played by thyroid gland seems to be essential for the full expression of the androgen-dependent SMG activity in adult mice.

Ontogenesis of androgen receptors in the mouse submandibular gland: correlation with the developmental profiles of circulating thyroid and testicular hormones.

Specific binding of the synthetic androgen, [17 alpha-methyl-3H]methyltrienolone, to the cytosol fraction of the submandibular salivary gland (SMG) of male mice was studied in relation to the developmental profiles of testosterone and thyroid hormones in blood. The peak rise of serum triiodothyronine (T3) at prepubertal age was closely related to both the increase of maximal androgen-binding capacity in SMG and the conspicuous surge of proliferative activity as indicated by increased rate of glandular DNA content. Also, 2-month thyroidectomized mice had an age-related, strong reduction in the number of androgen-binding sites. On the other hand, the development of the secretory functions of the gland could be better related to the rise of circulating testosterone by days 25-30 of age. The results suggest that thyroid hormones play a very important role in the early induction and further maintenance of androgen receptors in the murine SMG.

Differential actions of testosterone and its metabolites on mice submandibular gland.

Submandibular glands from male mice castrated at 21 days of age and killed 60 days thereafter exhibited impaired development of the granular ducts (GD), an effect which is directly related to its androgen-dependent feature. Testosterone and other related steroids of natural occurrence were given to these animals in order to determine the mechanism by which those compounds bring about recovery of their glandular histophysiology. The size and number of GD were reconstituted by the steroids in the following order of potency: 5 alpha-androstane-3 alpha, 17 beta-diol greater than testosterone propionate greater than 5 alpha-dihydrotestosterone greater than or equal to testosterone greater than 5 alpha-androstane-3 beta, 17 beta-diol. All of the drugs stimulated protein synthesis, but only 3 alpha-diol was also able to increase DNA synthesis. Results support the assumption that 3 alpha-diol exerts both proliferative and hypertrophic effects on mice SMG, possibly through some receptor-independent pathway(s); the action of the other steroids is essentially hypertrophic in nature.

Histological, morphometric and histochemical changes in the submandibular gland of the rat under experimental protein-calorie malnutrition.

Submandibular salivary glands of rats, subjected to experimental protein-calorie malnutrition, were studied by histologic, morphometric and histochemical methods. Marked alterations were observed. Acinar atrophy, a severe decrease in the volumetric proportion of the granular duct, and a decrease in the protein content of the granular duct cells were all recorded. Neutral mucosubstances were reduced in both acinar and granular duct cells.

Effects of testosterone and its metabolites in relation to androgen-binding activity in murine submandibular salivary glands.

The relative potencies of testosterone (T), testosterone propionate (TP) and other related steroids (5 alpha-dihydrotestosterone, DHT; 5 alpha-androstane-3 alpha, 17 beta-diol, alpha-diol; 5 alpha-androstane-3 beta, 17 beta-diol, beta-diol) in restoring some morphological and functional characteristics of submandibular gland (SMG) were investigated in castrated mice. The steroids restored to near-control values the glandular weight and total protein content, alpha-diol and TP being the most effective compounds tested; with regard to proteolytic activity stimulation, beta-diol was more effective than DHT. The alpha-diol metabolite was unique in significantly increasing DNA synthesis. In competition studies, alpha-diol and beta-diol were ineffective in displacing the specifically bound [3H]-R1881 from the SMG androgen-binding macromolecules. Thus T can elicit its effects on SMG without the need of prior conversion to DHT; there must be alternative, receptor-independent mechanisms whereby alpha- and beta-diol exert trophic/metabolic effects on murine SMG.

Morphological and morphometrical study of the kidney of the male tropical lizard Tropidurus torquatus.

A morphological and morphometrical study of the adult male Tropidurus torquatus kidney was undertaken. The nephron is composed of the following segments: renal corpuscle, neck segment, proximal convoluted tubule, intermediate segment, and distal tubule. The nephron is continued into the collecting duct and sexual segment. A large number of ciliated cells in the intermediate segment, the presence of 2 kinds of cells in the collecting ducts and a well developed permanently retained sexual segment were recorded as special features of this organ. The components of the renal parenchyma had the following relative volumes: proximal convoluted tubule = 56.4%, intermediate segment = 5.1%, distal tubule = 13.0%, collecting duct = 5.2%, and sexual segment = 11.6%.

Histochemistry of the kidney of the tropical lizard Tropidurus torquatus.

A histochemical analysis of glycoproteins, proteins, and some enzymes was done in kidneys from adult male lizards. The enzymes belong to different pathways of the cell metabolism which include EMBDEN-MEYERHOF and pentose-phosphate pathways, KREBS cycle, and to the lipid and protein metabolism. 2 cell types are described in the collecting duct, one being probably responsible for active transport and the other involved in mucous secretion. The proximal tubule, intermediate segment and distal tubule seem to perform an efficient aerobic metabolism. The proximal tubules probably take part in the final steps of uric acid formation. Aminic groups and the amino acids tyrosine, tryptophan, arginine, cysteine, and cystine are always present in the secretory granules of the sexual segment. These granules also have neutral glycoproteins and acid phosphatase activity.

Biochemical modulation of the submandibular salivary gland of castrated male mice treated with anabolic steroids.

The possibility that 19-nortestosterone decanoate, an anabolic steroid which has no androgenic effect in mice, may promote the recovery of certain biochemical parameters of the submandibular gland of castrated mice had been studied. It was demonstrated that protein, RNA and sialic acid concentrations, as well as, protease, acid phosphatase and succinate dehydrogenase activities were found to be similar to control values in the castrated mice treated with 19-nortestosterone decanoate (anabolic steroid) or testosterone propionale. The effects on seminal vesicle and levator ani muscle were also considered. The interaction between 19-nortestosterone decanoale and androgen-binding receptors in the submandibular gland is discussed.

Cytology and cytochemistry of the hypophysis of the freshwater teleost Rhamdia hilarii (Val., 1840).

The characterization of cell types in the rostral pars distalis, proximal pars distalis and pars intermedia of the Bagre fish hypophysis during the reproductive cycles, as well as a cytochemical study of mucosubstances were undertaken. The cytophysiological relationship among the different acidophilic, basophilic and chromophobic cells with the several hypophyseal hormones was also considered.

Morphology of the hypophysis of the freshwater teleost rhamdia hilarii (val., 1840).

The anatomical relationship between hypophysis and encephalon of the Bagre fish (Rhamdia hilarii, Val.) was studied. The subdivisions, morphology and the relative volume (%) of the different hypophyseal regions during the reproductive stage of the fish were also considered.

Immunohistochemical localization of erythropoietin in the rat and mouse submandibular gland.

There is a great deal of evidence to indicate that organs other than the kidney are involved in erythropoietin production. In this paper, it is reported that erythropoietin has been localized with an immunocytochemical method in the granular ducts of the submandibular glands of the rat and mouse.

Histochemical study of labial salivary glands in Sjögren's syndrome.

Human labial salivary gland biopsies of patients presenting connective tissue diseases associated with Sjögren's syndrome were submitted to a polysaccharide histochemistry study. The normal acinar secretion is an association of neutral polysaccharides with a sulphosialomucin. In Sjögren's syndrome, there is a great reduction in the secretory activity of the acinar cells, but no qualitative change was observed. The pathogenesis of this decreased production and its importance regarding the clinical manifestations of Sjögren's syndrome are discussed.