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1.
Neurosci Behav Physiol ; 38(8): 759-66, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18802775

RESUMO

The present review addresses analysis of data demonstrating the role of the hypothalamo-hypophyseal-adrenocortical axis (HHACA) in controlling pain sensitivity. Experiments on rats have demonstrated the analgesic effects of exogenous hormones of all components of the HHACA - corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and glucocorticoids - in the same models, and have also shown that the opioid and non-opioid mechanisms contribute to the development of the analgesia induced by these hormones. Endogenous glucocorticoids are involved in the development of analgesia mediated by non-opioid mechanisms. Along with the non-opioid mechanisms associated with endogenous glucocorticoids, the analgesic effect of ACTH can be mediated by the opioid mechanism. Unlike the situation with ACTH, the analgesic effect of CRH is mediated exclusively by non-opioid mechanisms, one of which is associated with HHACA hormones, while the other, appearing only on systemic administration, is not associated with these hormones. The actions of glucocorticoids on pain are mediated by neurons in the central gray matter of the midbrain.


Assuntos
Sistema Hipotálamo-Hipofisário/fisiopatologia , Dor/fisiopatologia , Hormônios Adeno-Hipofisários/fisiologia , Hormônios Neuro-Hipofisários/fisiologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Animais , Humanos , Dor/psicologia , Medição da Dor/efeitos dos fármacos , Hormônios Adeno-Hipofisários/farmacologia , Hormônios Neuro-Hipofisários/farmacologia , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia
2.
Clin Immunol ; 109(2): 197-202, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14597218

RESUMO

Initial studies on T cell development in the Snell Dwarf (dw/dw) strain of mice, which are deficient in the production of anterior pituitary hormones, have been interpreted to indicate a clear dependence of T cell development on endocrine system-derived factors. However, normal thymopoiesis in this strain has also been reported. The aim of the present study was to reconcile these contradictory data in order to define the role of anterior pituitary hormones in the thymus. The results indicated that if female dw/dw mice are housed together with their normal-sized littermates, thymic cellularity and the frequency of CD4(+)CD8(+) thymocytes are markedly reduced. However, administration of growth hormone could reverse these decreases seen in the double-positive T progenitor cells. Taken together, the data indicate that stress is the unifying parameter that can explain the disparate dw/dw mouse literature and suggest that endocrine effects on the T cell development can best be understood by interpreting the literature in this context.


Assuntos
Nanismo Hipofisário/imunologia , Abrigo para Animais , Hormônios Adeno-Hipofisários/deficiência , Hormônios Adeno-Hipofisários/farmacologia , Estresse Fisiológico/imunologia , Timo/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Feminino , Hormônio do Crescimento Humano/imunologia , Camundongos , Hormônios Adeno-Hipofisários/imunologia
3.
J Endocrinol ; 148(2): 193-6, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8699132

RESUMO

The effect of TRH on cell proliferation in the anterior lobe of the pituitary is well known and documented. On the other hand, there are no data on the effects of TRH on the intermediate lobe of the pituitary gland. The aim of this study was to investigate the effect of TRH and its analogues (pGlu-HIs-Gly, pGlu-His-Gly-NH2) on cell proliferation in the intermediate pituitary lobe. The bromodeoxyuridine technique was used to detect the proliferating cells. It was found that TRH stimulated cell proliferation 24 h after a single injection at a dose of 100 micrograms/kg body weight. The TRH analogues did not exert any significant stimulatory effect either 12 h or 24 h after the injection. The second experiment was carried out to distinguish the probable mechanism of the action of TRH. The effects of TSH and prolactin (PRL) on intermediate lobe cell proliferation were examined. It was found that both PRL and TSH exerted a significant stimulatory effect 24 h after a single s.c. injection of PRL at a dose of 150 IU/kg body weight or TSH at a dose 20 IU/kg body weight. It therefore appears that the stimulatory effect of TRH on intermediate pituitary lobe cell proliferation is mediated by PRL and TSH.


Assuntos
Hipófise/citologia , Hormônios Adeno-Hipofisários/farmacologia , Animais , Bromodesoxiuridina/metabolismo , Divisão Celular/efeitos dos fármacos , Sinergismo Farmacológico , Imuno-Histoquímica , Masculino , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Prolactina/farmacologia , Ratos , Ratos Wistar , Estimulação Química , Tireotropina/farmacologia , Hormônio Liberador de Tireotropina/farmacologia
4.
Acta Physiol Hung ; 84(2): 183-90, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9046364

RESUMO

The changes in the number and degranulation pattern of mast cells varied with the types of hormonal treatment and ovarian compartment. Luteinizing hormone (LH), follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH) and 17-beta estradiol (E2) treatment caused increase (P < 0.05) in the number of mast cells in the hilum as compared with the controls. Increase (P < 0.05) in the number of mast cells in the whole ovarian complex was observed only following FSH and E2 treatment. All the hormones used in the present study increased the percentage degranulation of mast cells in the hilum. However, only LH, FSH and E2 increased the percentage degranulation of mast cells in other compartments of the ovary (medulla, bursa and cortex). TSH and ACTH failed to cause any increase in the percentage degranulation of mast cells in these compartments. The present findings indicate E2 to be the most potent among the hormones tested in causing degranulation of mast cells in all ovarian compartments.


Assuntos
Estradiol/farmacologia , Mastócitos/citologia , Ovário/citologia , Hormônios Adeno-Hipofisários/farmacologia , Hormônio Adrenocorticotrópico/farmacologia , Animais , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/fisiologia , Estro , Feminino , Hormônio Foliculoestimulante/farmacologia , Hormônio Luteinizante/farmacologia , Mastócitos/efeitos dos fármacos , Mastócitos/fisiologia , Camundongos , Camundongos Endogâmicos , Ovário/efeitos dos fármacos , Ovário/fisiologia , Tireotropina/farmacologia
5.
J Endocrinol ; 143(3): 417-22, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7836885

RESUMO

The effects of growth hormone (GH) and prolactin (PRL) (1, 10, 100, 1000 or 10,000 ng/ml medium) on oxytocin, vasopressin, progesterone, cAMP and cGMP release by cultured bovine granulosa cells were studied. It was found that GH significantly stimulated oxytocin, vasopressin and cAMP but suppressed progesterone secretion. PRL tended to have the same pattern of action on nonapeptide, cAMP and steroid release, but its effect was not as great, with only a high supraphysiological dose (10,000 ng/ml) producing a statistically significant effect. No significant influence of GH on cGMP output was observed. Physiological doses of PRL (1, 10, 100 or 1000 ng/ml) significantly inhibited cGMP production whilst a high dose (10,000 ng/ml) resulted in stimulation. These observations suggested that GH may regulate ovarian oxytocin, vasopressin, progesterone and cAMP secretion. The effects of PRL on the release of these substances appeared to be non-specific, possibly resulting from its structural similarity to GH.


Assuntos
Células da Granulosa/metabolismo , Nucleotídeos Cíclicos/metabolismo , Hormônios Adeno-Hipofisários/farmacologia , Hormônios Neuro-Hipofisários/metabolismo , Progesterona/metabolismo , Animais , Bovinos , Células Cultivadas , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Feminino , Células da Granulosa/efeitos dos fármacos , Hormônio do Crescimento/farmacologia , Ocitocina/metabolismo , Prolactina/farmacologia , Estimulação Química , Vasopressinas/metabolismo
6.
Exp Eye Res ; 59(3): 291-6, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7821373

RESUMO

There is considerable evidence that the lens epithelium is the primary site of injury leading to the development of cataracts following radiation exposure. That the damaged cells of the epithelium are the progenitors of the aberrantly differentiating fibers associated with the cataract is indisputable. So too is the observation that post-radiation proliferative activity in the lens epithelium is required for cataracts to develop. The natural hormonal regulation of lens epithelial mitotic activity in the frog offers the opportunity to alter the cell cycle of the lens epithelium in vivo, thus enabling the direct examination of the role of lenticular mitosis in the cytopathomechanism of radiation-induced cataracts. The cell cycle of the lens epithelium of northern leopard frogs was manipulated by hypophysectomy (to halt mitotic activity) and pituitary hormone administration (to stimulate baseline mitosis and reverse hypophysectomy-induced mitotic suppression). Animals were hypophysectomized, irradiated and injected with pituitary hormone replacement. Irradiated animals, irradiated animals + hormone replacement and irradiated hypophysectomized animals served as controls. Cataract development was evaluated by slit-lamp biomicroscopy and correlated with histologic determinations of mitotic index and meridional row disorganization on lens epithelial whole mounts. In another study, hypophysectomized-irradiated animals received varying concentrations of replacement hormone in an attempt to quantitatively modulate lens epithelial mitotic activity and determine the effect on cataractogenesis. It was found that irradiated-hypophysectomized (mitosis halted) frogs failed to develop opacities, while those with hormonal replacement (mitosis reinstated) developed cataracts.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Catarata/etiologia , Cápsula do Cristalino/efeitos da radiação , Animais , Relação Dose-Resposta a Droga , Hipofisectomia , Cápsula do Cristalino/citologia , Mitose/efeitos dos fármacos , Índice Mitótico , Hormônios Adeno-Hipofisários/farmacologia , Rana pipiens , Fatores de Tempo
8.
Mol Cell Endocrinol ; 89(1-2): 153-62, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1338721

RESUMO

The expression of kidney androgen-regulated protein (KAP) gene in mouse kidney is regulated in a multihormonal fashion. As determined by in situ hybridization analysis, epithelial cells of proximal convoluted tubules of cortical nephrons express KAP mRNA in response to androgenic stimulation while similar cells in the juxtamedullary S3 segment of the tubules express KAP mRNA under estrogenic and pituitary hormonal control. In situ hybridization analysis of kidney sections using hypophysectomized (hypox) mice resulted in a total absence of KAP mRNA suggesting the participation of a pituitary hormone(s) in the constitutive expression of KAP mRNA in S3 cells. Treatment of hypox mice with steroid hormones showed that androgens restored the ability of cortical tubule cells to synthesize KAP mRNA. Estrogen treatment, on the other hand, partially induced KAP gene expression only in S3 cells. These results indicated that the androgenic response of the gene is independent of pituitary function, while expression in S3 cells, although partially induced by the direct action of estrogens, is primarily regulated by a pituitary factor. In order to elucidate which hormone(s) is responsible for KAP gene expression in S3 cells, individual pituitary hormones were administered to hypox normal animals and to strains of mice genetically deficient in certain pituitary hormones. Surgically treated C57BL/6 female and male mice were implanted for 7 days with osmotic pumps containing individual pituitary hormones, after which the kidneys were analyzed by in situ hybridization. Mice injected with growth hormone (GH), corticotropin (ACTH), prolactin (PRL), or vehicle failed to express KAP mRNA. Mice treated with thyrotropin (TSH), follitropin (FSH), and lutropin (LH) exhibited high levels of KAP mRNA in S3 cells of females as well as in the renal cortex of male animals. Expression in the cortex in response to LH and FSH may be due to their gonadotropic effect on testosterone production. Similarly, contamination of TSH samples with small amounts of the gonadotropins may explain the cortical response to TSH. TSH produced the strongest response in S3 cells suggesting that it is responsible for the permissive effect of the pituitary on KAP gene expression. This conclusion was supported by studies performed with the dwarf mouse (dw/dw) which lacks PRL, GH, and TSH due to a mutation in the pit-1 gene. In situ hybridization analysis of dwarf mice kidney sections showed a complete lack of KAP gene expression. The possible participation of GH and PRL was eliminated on the basis of the hormone replacement studies.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Nanismo Hipofisário/metabolismo , Estradiol/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônio do Crescimento/farmacologia , Túbulos Renais Proximais/efeitos dos fármacos , Hormônios Adeno-Hipofisários/farmacologia , Biossíntese de Proteínas , Testosterona/farmacologia , Hormônio Adrenocorticotrópico/farmacologia , Animais , Castração , Linhagem Celular , Nanismo Hipofisário/genética , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Feminino , Hormônio Foliculoestimulante/farmacologia , Humanos , Hipofisectomia , Hibridização In Situ , Túbulos Renais Proximais/metabolismo , Hormônio Luteinizante/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C3H/metabolismo , Camundongos Endogâmicos C57BL/metabolismo , Camundongos Mutantes/metabolismo , Prolactina/farmacologia , Proteínas/genética , Ratos , Ovinos
9.
J Endocrinol ; 129(1): 109-17, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1851510

RESUMO

There is increasing evidence implicating growth factors in the regulation of spermatogenesis and in-vitro studies have shown that epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) interact with the gonadotrophins in regulating testicular function. In the present study, the effect of FSH, testosterone and GH treatment on serum IGF-I and intratesticular EGF and IGF-I concentrations in adult male hypophysectomized rats treated with ethane dimethane sulphonate (EDS) to destroy Leydig cells has been investigated. Hypophysectomy alone or followed by EDS treatment was associated with a significant increase in intratesticular EGF concentrations compared with normal controls (P less than 0.05). Treatment of hypophysectomized animals with a combination of GH, FSH and testosterone resulted in a return of intratesticular EGF concentrations to normal control levels. In a second group of animals treated with a 5 cm silicone elastomer implant of testosterone and FSH, intratesticular EGF concentrations were also not significantly different from those of normal controls. Following hypophysectomy alone or hypophysectomy and EDS treatment, a significant increase in circulating IGF-I concentrations occurred, which was only reversed following the administration of GH. In addition, increases in testicular IGF-I concentrations were evident in all treated animals compared with controls, an effect which was only partially reversed in animals treated with a combination of FSH and testosterone (1.5 or 5 cm implant). Similar results were obtained with a combination of GH and FSH or GH and testosterone, although GH alone had no effect on testicular IGF-I concentrations. A combination of GH, FSH and testosterone restored testicular IGF-I to concentrations not significantly different from controls.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Substâncias de Crescimento/metabolismo , Mesilatos/farmacologia , Hormônios Adeno-Hipofisários/farmacologia , Testosterona/farmacologia , Animais , Fator de Crescimento Epidérmico/metabolismo , Hormônio Foliculoestimulante/farmacologia , Hormônio do Crescimento/farmacologia , Hipofisectomia , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Ratos , Ratos Endogâmicos , Testículo/efeitos dos fármacos , Testículo/metabolismo
10.
Epilepsia ; 32 Suppl 6: S60-7, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1959513

RESUMO

A hormone is an intrinsic substance carried via the blood to a target organ which is then functionally stimulated. Similar to extrinsically administered medications, the metabolism and function of the hormones may be altered by antiepileptic drugs (AEDs). The proposed mechanisms are (a) enhanced metabolism (natural steroids, synthetic steroids, e.g., decadron and birth control pills, thyroxine, and vitamin D3), (b) altered protein bonding (thyroxine, sex hormones), (c) impaired release into the systemic circulation (calcitonin, insulin, vitamin K clotting factors) and (d) altered end-organ effect. The AEDs most likely to interact with hormones are barbiturates, carbamazepine, and phenytoin.


Assuntos
Anticonvulsivantes/farmacologia , Hormônios/sangue , Anormalidades Induzidas por Medicamentos/etiologia , Anticonvulsivantes/efeitos adversos , Proteínas de Transporte/sangue , Proteínas de Transporte/farmacologia , Interações Medicamentosas , Epilepsia/tratamento farmacológico , Feminino , Hormônios Esteroides Gonadais/sangue , Hormônios Esteroides Gonadais/farmacologia , Hormônios/farmacologia , Humanos , Masculino , Hormônios Adeno-Hipofisários/sangue , Hormônios Adeno-Hipofisários/farmacologia , Esteroides/sangue , Esteroides/farmacologia , Hormônios Tireóideos/sangue , Hormônios Tireóideos/farmacologia
11.
Zh Vyssh Nerv Deiat Im I P Pavlova ; 40(6): 1158-64, 1990.
Artigo em Russo | MEDLINE | ID: mdl-1965259

RESUMO

In experiments on rats the influence was studied of tropic hormones of adenohypophysis--somatotropin, thyrotropin and adrenocorticotropin (STH, ThTN and ACTH respectively) on the elaboration and extinction of conditioned reaction of active avoidance (CRAA) in Y-maze and behaviour in the open field under microinjections of hormones into the brain lateral ventricle (0.001-0.002 ME). It has been shown that all studied hormones improve animals learning at negative pain reinforcement; ThTH and ACTH retard it in contrast to STH, which accelerates the extinction of the elaborated CRAA; tropic hormones exert differentiated influence on rats behaviour in the open field. No distinct correlation was found between behavioural manifestation and the level of catecholamines in the rats hypothalamus.


Assuntos
Comportamento Animal/efeitos dos fármacos , Hormônios Adeno-Hipofisários/farmacologia , Hormônio Adrenocorticotrópico/farmacologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Comportamento Animal/fisiologia , Catecolaminas/metabolismo , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Clássico/fisiologia , Hormônio do Crescimento/farmacologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Injeções Intraventriculares , Masculino , Hormônios Adeno-Hipofisários/administração & dosagem , Ratos , Reforço Psicológico , Tireotropina/farmacologia
12.
Biull Eksp Biol Med ; 107(1): 91-3, 1989 Jan.
Artigo em Russo | MEDLINE | ID: mdl-2914182

RESUMO

Leydig cells reaction of rabbits testis to choriogonin action has been investigated during the prenatal period of ontogenesis. It has been found, that these cells sensitivity to the hormones studied has been detected at the early stages of embryogenesis. The specialization of Leydig cells response to choriogonin, thyrotrophin and prolactin in the process of prenatal period has been shown.


Assuntos
Embrião de Mamíferos/efeitos dos fármacos , Células Intersticiais do Testículo/efeitos dos fármacos , Hormônios Adeno-Hipofisários/farmacologia , Animais , Gonadotropina Coriônica/administração & dosagem , Gonadotropina Coriônica/farmacologia , Feminino , Idade Gestacional , Masculino , Hormônios Adeno-Hipofisários/administração & dosagem , Gravidez , Prolactina/administração & dosagem , Prolactina/farmacologia , Coelhos , Testosterona/sangue , Tireotropina/administração & dosagem , Tireotropina/farmacologia
13.
J Clin Endocrinol Metab ; 67(4): 707-12, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2458377

RESUMO

Synthetic peptides, representing specific portions of the alpha-subunit of the human glycoprotein hormones, can inhibit both the binding of labeled TSH to thyroid membranes and adenylate cyclase stimulation by TSH in vitro. The same synthetic peptides (alpha 26-46 and alpha 31-45) significantly (P less than 0.05) inhibited the adenylate cyclase-stimulating activity of thyroid-stimulating immunoglobulins (TSI) from 10 patients with hyperthyroid Graves' disease. Peptide alpha 26-46 was the most potent, resulting in 79.1 +/- 8.8% (+/- SE) inhibition at 133 micrograms/mL, while peptide alpha 31-45 inhibited TSI activity by 36.3 +/- 5.2%. Peptides alpha 61-75 and alpha 81-92, that had only minimal ability to inhibit TSH-mediated cAMP generation, did not significantly inhibit TSI activity. The inhibitory action of alpha 26-46 was dose dependent, and a significant negative correlation was found between the maximum TSI activity of the serum sample and the inhibition achieved by the synthetic peptide, suggesting that differences in TSI affinity and/or titer may account for the variable inhibitory activity of the peptides. These results suggest that TSI interact with the TSH receptor at the site that recognizes the portion of the TSH alpha-subunit represented by the synthetic peptide alpha 26-46 and, thus, support the concept that the TSH-binding site of the TSH receptor is the site of antigen binding between TSI and the thyroid cell.


Assuntos
Doença de Graves/imunologia , Imunoglobulina G/fisiologia , Hormônios Adeno-Hipofisários/farmacologia , AMP Cíclico/biossíntese , Feminino , Subunidade alfa de Hormônios Glicoproteicos , Humanos , Imunoglobulina G/antagonistas & inibidores , Imunoglobulina G/metabolismo , Imunoglobulinas Estimuladoras da Glândula Tireoide , Masculino , Receptores da Tireotropina/imunologia
14.
Endocrinology ; 123(2): 700-12, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2456202

RESUMO

Renotropic activity was previously demonstrated in an ovine LH preparation. This preparation was further purified with a series of chromatographic steps, and the fractions were assayed for renotropic activity in vivo by their ability to stimulate [3H]thymidine incorporation into renal DNA of castrated hypophysectomized male rats. A purified preparation could be dissociated by acid treatment into two major constituent subunits, designated alpha and beta, each of which was composed of three microheterogeneous components (subunits alpha 1-3 and beta 1-3) by reverse phase HPLC. Peptide mapping, including amino acid analyses and partial sequencing of the purified peptides, showed that 1) subunits alpha 3 and beta 3 possess the full length of the polypeptide chains, with the same amino acid sequences as those of the corresponding LH subunits alpha and beta, respectively; and 2) subunits alpha 1 and alpha 2 are complexes of three polypeptides which are missing several N-terminal residues from subunit alpha 3. Conversely, subunits beta 1 and beta 2 lack the C-terminal two residues and one residue, respectively, of subunit beta 3. Renotropic activity was not detected in any of the dissociated subunits alone, but association of alpha 1-3 with beta 1-3 reconstituted the hormonal activity with different potencies. In particular, combination of subunits alpha 3 and beta 3 (alpha 3.beta 3) yielded a potent renotropic activity with weak gonadotropic activity. The carbohydrate composition of the purified preparation exhibiting renotropic activity differed from that of a reference oLH preparation, which possessed greater gonadotropic activity but was devoid of renotropic activity. Furthermore, renotropic activity was decreased after removal of sialic acid by treatment with neuraminidase. Thus, the oligosaccharide moieties as well as the amino acid sequences of the subunits may play an important role in the expression of renotropic activity in vivo, these effects over and above those arising from differential metabolic clearance. We conclude that pituitary renotropin represents a novel activity of a LH- isoform(s) and that the posttranslational (or the artificial, i.e. during preparation) modification of the constituent LH subunits may be responsible for modulation of renotropic activity as well as the intrinsic gonadotropic activity.


Assuntos
DNA/biossíntese , Rim/metabolismo , Hormônio Luteinizante/farmacologia , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Carboidratos/análise , Cromatografia , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Subunidade alfa de Hormônios Glicoproteicos , Concentração de Íons de Hidrogênio , Rim/efeitos dos fármacos , Hormônio Luteinizante/isolamento & purificação , Masculino , Dados de Sequência Molecular , Peso Molecular , Neuraminidase/metabolismo , Fragmentos de Peptídeos , Hormônios Adeno-Hipofisários/isolamento & purificação , Hormônios Adeno-Hipofisários/farmacologia , Radioimunoensaio , Ratos , Ratos Endogâmicos , Tripsina
15.
Horm Metab Res Suppl ; 19: 44-9, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3235059

RESUMO

Peptide hormones are potent stimulators of lipolysis in incubated adipocytes or adipose tissue of laboratory animals. However, none out of 40 synthetic or highly purified peptide hormones or sequences from the pituitary, the gastrointestinal tract and of different origin was able to stimulate glycerol release from 'incubated' human adipocytes. Yet, this model of the 'incubated adipocyte' offers several disadvantages: rapid decrease of pH in the incubation medium, release and increment of lipolysis inhibiting substances such as FFA and adenosine and rapid unspecific degradation of the peptides. In an improved in vitro model--pH-stat titration--which avoids or diminishes the disadvantages of 'incubated adipocytes', a group of pituitary peptides was tested. One peptide hormone, beta-lipotropin, stimulated lipolysis significantly in human adipose tissue. Two other peptides which were highly active in adipose tissue of laboratory animals were ineffective in this system too. The lipolytic response to beta-lipotropin was comparable to the effect of noradrenaline at equimolar concentrations. The data indicate that results on the lipolytic activity of peptide hormones in adipose tissue of laboratory animals cannot be transferred to human adipose tissue. In advanced in vitro test systems the ability to stimulate lipolysis could also be shown for a peptide hormone suggesting a role of such substances in the endocrine regulation of adipose tissue mass in men.


Assuntos
Tecido Adiposo/metabolismo , Hormônios/farmacologia , Lipólise/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Endorfinas/farmacologia , Hormônios Gastrointestinais/farmacologia , Humanos , Técnicas In Vitro , Cinética , Hormônios Adeno-Hipofisários/farmacologia , Hormônios Neuro-Hipofisários/farmacologia , Valores de Referência
16.
Mol Cell Endocrinol ; 50(1-2): 23-7, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3034698

RESUMO

The effect of adenohypophysial hormones on rat pineal melatonin content and release was examined in vitro. Medium concentration of radioimmunoassayable melatonin decreased after a 6 h exposure to 1-100 ng/ml FSH; pineal levels of melatonin were only decreased by 100 ng/ml FSH. LH (1-100 ng/ml) augmented significantly medium melatonin concentration, tissue levels being increased at 10 ng/ml LH. Parallel increases of explant and medium melatonin content were found after exposure to 1-100 ng/ml TSH. At the smallest concentration employed (1 ng/ml) prolactin increased melatonin content and release while at 100 ng/ml a significant depression of both parameters was found. Growth hormone (1-10 ng/ml) augmented melatonin levels in medium but failed to modify them at 100 ng/ml, although at this concentration tissue melatonin levels increased. ACTH did not modify pineal melatonin synthesis in vitro.


Assuntos
Melatonina/metabolismo , Glândula Pineal/metabolismo , Hormônios Adeno-Hipofisários/farmacologia , Hormônio Adrenocorticotrópico/farmacologia , Animais , Hormônio Foliculoestimulante/farmacologia , Hormônio do Crescimento/farmacologia , Hormônio Luteinizante/farmacologia , Masculino , Técnicas de Cultura de Órgãos , Glândula Pineal/efeitos dos fármacos , Prolactina/farmacologia , Ratos , Tireotropina/farmacologia
17.
Fed Proc ; 46(2): 290-4, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3803619

RESUMO

Muscle cell culture techniques have been used for several years in research on muscle growth and development. Several types of culture systems have been devised, including primary cultures from embryonic or postnatal muscle and myogenic cell lines. In addition, serum-free and serum-containing media have been developed to address specific muscle development questions. Many of these questions center around muscle cell differentiation and muscle cell physiology; and, more recently, muscle cell cultures have been used as bioassay tools for examining growth physiology in domestic animals. In our laboratory, skeletal muscle satellite cells have been studied in vitro to evaluate the effect of several protein hormones and growth factors on satellite cell proliferation and differentiation. Of the hormones examined, only the insulin-like growth factors/somatomedins and fibroblast growth factor have been shown to have a stimulatory effect on proliferation that could be physiologically significant. None of the major anterior pituitary hormones interacted directly with satellite cells to stimulate proliferation. With advances in serum-free medium formulations and cell separation techniques, more information can be obtained from experiments with muscle cell cultures. With appropriate design and interpretation, our knowledge of muscle growth in domestic animals will be expanded.


Assuntos
Animais Domésticos/crescimento & desenvolvimento , Células Cultivadas , Desenvolvimento Muscular , Fatores Etários , Animais , Diferenciação Celular , Divisão Celular , Separação Celular , Meios de Cultura , Fatores de Crescimento de Fibroblastos/farmacologia , Fator de Crescimento Insulin-Like II/farmacologia , Músculos/citologia , Hormônios Adeno-Hipofisários/farmacologia , Ratos , Pesquisa , Somatomedinas/farmacologia , Estimulação Química
18.
J Steroid Biochem ; 27(1-3): 565-71, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-2447392

RESUMO

The time course for the decrease in norepinephrine concentration of rat pineal explants in culture indicated a significant fall starting at the 4th hour and completed after 16-24 h of incubation. Significant decreases of serotonin and 5-hydroxyindoleacetic acid (HIAA) levels in tissue, an increase of HIAA/serotonin ratio, and an increase of melatonin production rate in vitro were also observed as a function of the incubation time. Estradiol (10(-7)-10(-5) M) increased rat pineal melatonin content, testosterone (10(-5) M) decreased it and progesterone was devoid of activity when incubated with explants for up to 6 h. The in vitro stimulatory effect of estradiol on rat pineal methoxyindole synthesis was blocked by propranolol but not by phentolamine; propranolol also blocked the increase of nuclear estradiol-receptor complex produced by estrogen exposure of pineal explants. TSH (1-100 ng/ml), growth hormone (10-100 ng/ml) and LH (10 ng/ml) augmented rat pineal melatonin content while 100 ng/ml of FSH decreased it significantly. Prolactin exerted a biphasic effect on rat pineal explants, the lowest concentration augmenting melatonin content while the high concentration depressed it. Deep, intermediate and superficial segments of guinea-pig pineal glands showed an increase in melatonin concentration after a 6-h incubation in the presence of 10(-7)-10(-5) M estradiol.


Assuntos
Hormônios Esteroides Gonadais/farmacologia , Melatonina/biossíntese , Glândula Pineal/efeitos dos fármacos , Hormônios Adeno-Hipofisários/farmacologia , Animais , Cobaias , Ácido Hidroxi-Indolacético/metabolismo , Masculino , Norepinefrina/metabolismo , Técnicas de Cultura de Órgãos , Fentolamina/farmacologia , Glândula Pineal/metabolismo , Propranolol/farmacologia , Ratos , Receptores de Estradiol/metabolismo , Serotonina/metabolismo
19.
Gen Comp Endocrinol ; 64(2): 220-38, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3557090

RESUMO

Juvenile coho salmon, Oncorhynchus kisutch, were either immersed in thyroxin-containing water (T4; 20 micrograms/ml) or implanted with cortisol (5 mg), bovine growth hormone (GH; 1.5 microgram/g body wt), or ovine prolactin (PRL; 1.5 microgram/g body wt), both early and late in smoltification. T4 and cortisol treatment stimulated lipid mobilization in parr. T4-stimulated lipid mobilization was indicated by decreased total lipids, primarily as triacylglycerols, and increased lipolytic enzyme (triacylglycerol lipase) activity in the liver and dark muscle. T4-stimulated lipid mobilization from mesenteric fat was indicated by decreased total tissue mass and by increased lipase activity. Cortisol caused significant reductions in total lipid concentration and triacylglycerol content of the liver and dark muscle; these effects were accompanied by increased lipase activity. Cortisol treatment did not affect mesenteric fat total lipid concentration, total tissue mass, or triacylglycerol content. However, cortisol implantation did enhance mesenteric fat lipase activity. Thyroxin and cortisol treatment failed to elicit alterations in the pattern of tissue lipid mobilization of smolts. GH stimulated lipid mobilization from coho salmon parr. Depletion of liver total lipids was accompanied by increased lipolytic enzyme (triacylglycerol lipase) activity. GH had limited effects on dark muscle and mesenteric fat. In smolts, GH had virtually no effect on lipid mobilization. PRL strongly stimulated lipid mobilization in parr; this effect was evident in all depots studied (liver, dark muscle, mesenteric fat). Decreases in total lipid concentration, or in total tissue mass (mesenteric fat), were accompanied by increased lipase activity and generally resulted in reduced tissue triacylglycerol content. Smolts appeared refractory to PRL treatment. Smolts (characteristically possessing elevated liver lipase activity) that were hypophysectomized exhibited low levels of liver lipase activity. Cortisol replacement restored enzyme activity to approximately the same levels as those observed in sham-operated controls. GH replacement restored lipase activity, but not to the levels observed in sham-operated controls. These results indicate that T4, cortisol, GH, and PRL all stimulate lipid mobilization in developing salmon by enhancement of lipolysis and suggest that T4, cortisol, GH, and PRL are among the factors which contribute to smoltification-associated lipid depletion.


Assuntos
Adaptação Fisiológica , Hidrocortisona/farmacologia , Metabolismo dos Lipídeos , Hormônios Adeno-Hipofisários/farmacologia , Salmão/metabolismo , Tiroxina/farmacologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Hormônio do Crescimento/farmacologia , Hipofisectomia , Lipase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismo , Prolactina/farmacologia , Estações do Ano , Água do Mar
20.
Biol Reprod ; 35(3): 493-500, 1986 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2431722

RESUMO

Previous studies have shown that equine luteinizing hormone (eLH) inhibits production of cyclic adenosine monophosphate (cAMP) induced by follicle-stimulating hormone (FSH) in preparations of seminiferous tubules from immature rats. It was also shown that the inhibitory effect was a function of the equine LH (eLH) alpha subunit. To explore this phenomenon further, the intrinsic FSH-like activities of eLH alpha alone and in combination with ovine (o) LH beta, ovine FSH beta, and equine FSH beta were evaluated in several assay systems. In a radioreceptor assay employing 125I-o-FSH and testis membranes from day-old calves, eLH was twice as active as oFSH, eLH alpha was 6% as active as oFSH, and other subunits showed a lack of activity (less than 1.5%). Whereas oLH was only 0.1% as active as oFSH, the hybrid eLH alpha-oLH beta was 3.0% as active. The binding activity of eLH alpha-FSH beta hybrids tended to be higher than the oFSH alpha-FSH beta hybrids. In the cAMP production assay, eLH alpha-FSH beta hybrids exhibited dampened dose-response curves when compared to the oFSH alpha-FSH beta hybrids. In a plasminogen activator assay (PAA) employing granulosa cells from intact 21-24-day-old female rats primed with diethylstilbestrol, eLH had activity comparable to that of oFSH, while eLH alpha was inactive. When eLH alpha was recombined with oFSH beta, eFSH beta, or oLH beta, the PAA stimulatory activity was not altered compared to that of the hybrids oLH alpha-oFSH beta, oFSH alpha-eFSH beta, and the recombinant oLH alpha-oLH beta, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Hormônio Foliculoestimulante/farmacologia , Hormônio Luteinizante/farmacologia , Fragmentos de Peptídeos/farmacologia , Hormônios Adeno-Hipofisários/farmacologia , Animais , Bioensaio , Bovinos , Interações Medicamentosas , Subunidade beta do Hormônio Folículoestimulante , Subunidade alfa de Hormônios Glicoproteicos , Cavalos , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Ativadores de Plasminogênio/biossíntese , Ensaio Radioligante , Proteínas Recombinantes/farmacologia , Células de Sertoli/efeitos dos fármacos , Ovinos
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