RESUMO
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).
Assuntos
Estradiol/sangue , Peixes , Hormônio Liberador de Gonadotropina/análogos & derivados , Hidrocortisona/sangue , Indução da Ovulação , Testosterona/sangue , Análise de Variância , Animais , Feminino , Radioimunoensaio , Sensibilidade e EspecificidadeRESUMO
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).
Assuntos
Animais , Feminino , Estradiol/sangue , Peixes , Hormônio Liberador de Gonadotropina/análogos & derivados , Hidrocortisona/sangue , Indução da Ovulação , Testosterona/sangue , Análise de Variância , Radioimunoensaio , Sensibilidade e EspecificidadeRESUMO
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.
Assuntos
Glucose/metabolismo , Intestino Delgado/metabolismo , Glândula Submandibular/fisiologia , Animais , Descarboxilação , Células Epiteliais , Epitélio/metabolismo , Hexoquinase/metabolismo , Intestino Delgado/citologia , Lactatos/biossíntese , Masculino , Camundongos , Glândula Submandibular/cirurgia , Fatores de TempoRESUMO
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.
Assuntos
Envelhecimento/metabolismo , Carcinoma 256 de Walker/enzimologia , Glutaminase/metabolismo , Linfonodos/enzimologia , Baço/enzimologia , Timo/enzimologia , Animais , Imuno-Histoquímica , Masculino , Mesentério , Transplante de Neoplasias , Fosfatos/metabolismo , Ratos , Ratos WistarRESUMO
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
Assuntos
Animais , Masculino , Envelhecimento/metabolismo , /enzimologia , Glutaminase/metabolismo , Linfonodos/enzimologia , Baço/enzimologia , Timo/enzimologia , Imuno-Histoquímica , Mesentério , Transplante de Neoplasias , Fosfatos/metabolismo , Ratos , Ratos WistarRESUMO
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.