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1.
Gan To Kagaku Ryoho ; 27(3): 395-403, 2000 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-10740633

RESUMO

This interim analysis of the JFMTC study as of May, 1998 covers 321 gastrectomized patients with far-advanced stomach cancer from 135 institutions between November, 1993 and March, 1996. The intensive therapy group (I-group) received CDDP i.p. administration on resective surgery with 70 mg/m2 followed by CDDP i.v. of 80 mg/m2 (day 1, i.v.), accompanying 5-FU of 350 mg/m2/day (day 1-5, c.v.i.) in the 4th, 8th and 12th weeks. The I-group was randomly compared with the standard therapy group (S-group) of MMC of 6 mg/m2 i.v. in the 4th, 8th and 12th weeks and UFT of 3-4 capsules daily for postoperative one year. The results obtained were that 1. adverse reactions were found more in the I-group than in the S-group, particularly notable in the decrease in blood cells, loss of appetite and nausea/vomiting, and incidence of grade 3 or more being 13% (neutrophile leukocytes), 26% and 21%, respectively; 2. there was no significant difference between I- and S-groups in terms of 3-year survival or disease-free survival rates. (JFMTC: Japanese Foundation of Multidisciplinary Treatment for Cancer).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias Gástricas/tratamento farmacológico , Cisplatino/administração & dosagem , Esquema de Medicação , Avaliação de Medicamentos , Fluoruracila/administração & dosagem , Humanos , Neoplasias Gástricas/mortalidade , Taxa de Sobrevida , Tegafur/administração & dosagem , Uracila/administração & dosagem
2.
Anticancer Res ; 18(6B): 4629-34, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9891531

RESUMO

We examined the effects of postoperative 5-fluorouracil (5-FU) infusions and oral treatment with 1-hexylcarbamoyl-5-fluorouracil (HCFU) on patients curatively resected for stages II-IV colorectal cancer. The study was prospectively randomized, and 251 (93.3%) of 269 patients were valid candidates for statistical assessment. The inductive regimen for group A included 5-FU 10 mg intravenous (i.v.) injections on days 0, 1, 2, 7, 8 and 9, postoperatively. For maintenance therapy, group A received HCFU 300 mg orally and daily for 52 weeks beginning 2 weeks after surgery. The regimen for group B included only 5-FU injections. The effects of this chemotherapy were also retrospectively analyzed for groups at a high risk for recurrence, stages III-IV, transmural invasion-positive and lymph node metastasis-positive cases. There was no statistical difference in survival time between the groups for 251 eligible cases (p = 0.079). In group A given 5-FU plus HCFU, there was a reduction in the recurrence rate for patients with stages III-IV or lymph node metastasis-positive colorectal cancers (p < 0.05) and prolongation of the survival time for patients with stage III-IV, transmural invasion-positive or lymph node-positive colorectal cancers (p < 0.05). Our findings show that the combination of 5-FU infusion and the continuous administration of HCFU is effective in treating patients with surgically resected colorectal cancer who are at high risk for a recurrence.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/cirurgia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/cirurgia , Fluoruracila/análogos & derivados , Fluoruracila/uso terapêutico , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/cirurgia , Administração Oral , Adulto , Idoso , Antimetabólitos Antineoplásicos/uso terapêutico , Quimioterapia Adjuvante , Neoplasias do Colo/mortalidade , Neoplasias do Colo/patologia , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Neoplasias Retais/mortalidade , Neoplasias Retais/patologia , Recidiva , Medição de Risco , Fatores de Risco , Análise de Sobrevida , Fatores de Tempo
3.
Gan To Kagaku Ryoho ; 23(7): 929-32, 1996 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-8678545

RESUMO

We described a case of advanced gastric cancer accompanied by metastasis to the periaortic lymph node. Two cycles of the neoadjuvant chemotherapy consisting of 5-FU and low-dose CDDP (FP therapy) were given. 5-FU (800mg/body/day) was administered as a continuous intravenous infusion for five days, and CDDP (10mg/body/day) was given as an intravenous infusion for an hour on days 1-5. The FP therapy resulted in a significant effect in the metastatic periaortic lymph node. Then, total gastrectomy with combined resection of spleen was done. Histological examination of the resected specimen revealed the histological effect showing Grade 3 in the primary site and Grade 2 in the periaortic lymph node. The patient is alive with no evidence of recurrence 13 months after operation. Thus, FP therapy is thought to be effective against advanced gastric cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Idoso , Aorta , Quimioterapia Adjuvante , Cisplatino/administração & dosagem , Terapia Combinada , Esquema de Medicação , Fluoruracila/administração & dosagem , Gastrectomia , Humanos , Metástase Linfática , Masculino , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia
4.
Cancer ; 77(1): 36-43, 1996 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-8630937

RESUMO

BACKGROUND: Colorectal cancer is one of the major malignant diseases and, recently, its incidence appears to be increasing. Surgical resectability is an important prognostic determinant; however, recurrent tumors are commonly noted, even after apparently curative surgery. Because such metastatic disease cannot be cured, better adjuvant therapies are urgently called for. METHODS: We studied the effect of postoperative chemotherapy using 5-fluorouracil (5-FU) infusions and 1-hexylcarbamoyl-5-fluorouracil (HCFU) oral administration for curatively resected Stage II to IV colorectal cancer. This study was prospectively randomized and controlled and 251 (93.3%) of 269 patients were determined to be candidates for statistical assessment. The inductive regimen for Group A included a total of 6 5-FU intravenous injections, 10 mg/kg, on postoperative days 0, 1, 2, 7, 8, and 9. For maintenance therapy, Group A also received oral HCFU, 300 mg daily for 52 weeks beginning 2 weeks after surgery. The regimen for Group B included only 5-FU injections of Group A. RESULTS: There were no differences in the prognostic factors or doses of 5-FU between Groups A and B. In addition, no difference was observed in the toxicity rate between the two groups. Group A, with 5-FU infusions plus oral HCFU administration, produced a reduction in the recurrence rate and a prolongation of the survival time for patients with rectal cancer. In a retrospective analysis, this protocol was also effective for patients with Stage III to IV, wall invasion-positive, and lymph node metastasis-positive colorectal cancers. CONCLUSIONS: This study suggests that the combination of 5-FU infusions and the continuous oral administration of HCFU is a reasonable therapeutic approach for patients with surgically resected colorectal cancer and a high risk of recurrence.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Quimioterapia Adjuvante , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/análogos & derivados , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Taxa de Sobrevida
5.
JPEN J Parenter Enteral Nutr ; 19(6): 492-7, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8748364

RESUMO

BACKGROUND: Since tumor-bearing rats are deficient in glutamine, we investigated whether (1) glutamine and glutathione deficiency occur in tumor-bearing rats, (2) glutamine supplementation caused an increase of glutathione levels in host tissues and tumor, (3) glutamine enhances protein synthesis in host tissues, and (4) glutamine stimulated the tumor to synthesize protein and DNA. METHODS: Male Donryu rats were randomized into four groups: (1) non-tumor-bearing rat (NTB) + standard total parenteral nutrition (STPN); (2) NTB + glutamine-supplemented TPN (GTPN); (3) tumor-bearing rat (TB) + STPN; (4) TB + GTPN. On day 0 AH109A rat hepatoma cells were subcutaneously injected into the backs of rats to induce tumor. The animals were maintained on TPN for 6 days from day 10 through day 15. On day 15, 1-14C-leucine was given by a 5-hour continuous infusion (2.0 microCi/h per rat) to determine the fractional synthesis rate and endogenous leucine production. The levels of glutamine and glutathione were measured by HPLC. the tumor DNA synthesis was estimated by bromodeoxyuridine labeling index. RESULTS: Tumor development led to a significant weight loss, but this weight loss was significantly lessened by glutamine supplementation because of an increase in muscle protein synthesis. Glutamine did not enhance tumor weight, protein, and DNA synthesis in the tumor. Tumor development caused a significant reduction of glutathione in the muscle, jejunum, and liver, but supplemented glutamine increased the levels of glutathione in the jejunum. CONCLUSION: Glutamine supplementation is beneficial in preventing deficiencies of glutamine and glutathione and in improving protein metabolism in tumor-bearing rats.


Assuntos
Glutamina/administração & dosagem , Glutationa/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Nutrição Parenteral Total , Proteínas/metabolismo , Animais , DNA de Neoplasias/biossíntese , Glutamina/metabolismo , Jejuno/metabolismo , Fígado/metabolismo , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas Experimentais/terapia , Masculino , Músculos/metabolismo , Transplante de Neoplasias , Ratos , Células Tumorais Cultivadas
6.
J Surg Res ; 59(4): 475-81, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7564320

RESUMO

One of the physiological roles of glutamine is as a precursor for DNA synthesis. The aims of this study were to determine (1) whether glutamine-supplemented total parenteral nutrition (TPN) enhanced DNA and protein synthesis in the liver and (2) whether glutamine uptake was increased following partial hepatectomy in rats. Male Donryu rats (n = 59; body weight, 250-275 g) were randomized into four groups: (1) sham operation + standard TPN solution (C-STPN); (2) C + glutamine-supplemented TPN (C-GTPN); (3) 70% partial hepatectomy + STPN (H-STPN); (4) partial hepatectomy + GTPN (H-GTPN). On Day 0, rats underwent either a sham operation or 70% partial hepatectomy and concomitantly were catheterized in the jugular vein. TPN was begun immediately after the surgery. GTPN was isocaloric and isonitrogenous with STPN and 25% of total nitrogen was given as glutamine. On Day 2, the animals were sacrificed after either a continuous infusion of 1-14C-leucine or a bolus i.v. injection of bromodeoxyuridine. The rate of hepatic regeneration was enhanced with glutamine supplementation (H-STPN, 60.8 +/- 1.6% vs H-GTPN, 66.3 +/- 2.0, P < 0.05) due to an increase in protein synthesis in the liver (H-STPN, 134.0 +/- 10.3%/day vs H-GTPN, 160.9 +/- 6.9, P < 0.05) and DNA synthesis in hepatocytes (H-STPN, 23.1 +/- 2.5% vs H-GTPN, 31.4 +/- 2.9, P < 0.05). The uptake of glutamine by the liver was increased following hepatectomy with GTPN supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
DNA/biossíntese , Glutamina/administração & dosagem , Hepatectomia , Regeneração Hepática , Fígado/metabolismo , Biossíntese de Proteínas , Animais , Peso Corporal , Bromodesoxiuridina/metabolismo , Divisão Celular , Mucosa Intestinal/metabolismo , Fígado/citologia , Masculino , Ratos
7.
J Surg Res ; 57(1): 143-9, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8041129

RESUMO

Supplemental glutamine prevents gut atrophy and enhances muscle protein synthesis in septic rats. This study investigated the effect of glutamine administration and mitomycin C treatment on protein turnover in tumor-bearing rats. AH109A rat ascites hepatoma cells (2 x 10(6)) were subcutaneously implanted in the back of male Donryu rats (n = 32, body weight 150-200 g) on Day 0. The animals were then fed rat chow ad libitum for 10 days. On Day 10, the rats were catheterized for TPN and randomized into four groups according to diet and treatment. The groups were: (i) standard total parenteral nutrition (STPN) + saline; (ii) glutamine-supplemented TPN (GTPN) + saline; (iii) STPN+mitomycin C (MMC); (iv) GTPN+MMC. GTPN was isocaloric (250 kcal/kg/day) and isonitrogenous (1.5 gN/kg/day) with STPN. The animals were maintained on TPN for 5 days and received mitomycin C (0.5 mg/kg) via the catheter every day. On the fifth day of TPN, [1-14C]leucine was given via a 5-hr continuous infusion (2.0 microCi/hr/rat) to determine the fractional synthesis rate of muscle, gut mucosa, liver, and tumor. Also, endogenous leucine production (not equal to whole body protein breakdown rate) was calculated. Body weight loss during TPN was reduced with GTPN. GTPN enhanced muscle FSR in untreated animals (STPN: 10.8 +/- 8.7%/day vs GTPN: 14.7 +/- 0.6%/day, P < 0.05) and in mitomycin C-treated animals (STPN+MMC: 9.6 +/- 0.9%/day, GTPN+MMC: 12.0 +/- 0.8%/day, P < 0.05). The whole body protein breakdown rate was reduced with GTPN. Mitomycin C reduced the mucosal fractional synthesis rate and GTPN did not prevent this reduction.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Antineoplásicos/farmacologia , Carcinoma Hepatocelular/metabolismo , Glutamina/farmacologia , Neoplasias Hepáticas Experimentais/metabolismo , Mitomicina/farmacologia , Proteínas/metabolismo , Animais , Mucosa Intestinal/metabolismo , Leucina/biossíntese , Fígado/metabolismo , Masculino , Músculos/metabolismo , Proteínas de Neoplasias/biossíntese , Nutrição Parenteral Total , Ratos , Ratos Endogâmicos
8.
Nihon Geka Gakkai Zasshi ; 94(10): 1078-84, 1993 Oct.
Artigo em Japonês | MEDLINE | ID: mdl-8232182

RESUMO

The objectives of these experiments were to investigate the effect of Gln supplementation on protein metabolism and immune function in septic rats. (Experiment 1): 73 SD female rats were catheterized for TPN into the jugular vein on day 1. On day 4, the rats were randomized into 4 group: 1) control (C)+Standard TPN (STPN), 2) (C)+Gln TPN (GTPN), 3) sepsis (S)+STPN, 4) S+GTPN. Sepsis was induced by injection of 10(10) C. Coli/kg from the TPN catheter. U-14C-leucine or 15N2-Urea was given before sacrifice on day 5. (Experiment 2): 48 SD male rats were randomized into 3 groups, 1) normal control rat (NC), fed as lib. 2) peritonitis (P)+STPN, 3) P+GTPN. On day 1, 34 rats were catheterized and either STPN or GTPN was begun. On day 3, 6 hours after serum cecum ligation and puncture, resuscitation was done. On day 5, rats were sacrificed. The results were as follows: 1) FSR of ileum, proximal colon, distal colon and muscle were augmented by GTPN, 2) Sepsis caused a significant increase of urea production, but GTPN prevented this increase, 3) lymphocyte blastogenation was decreased with sepsis, but GTPN improved this reduction, 4) Phagocytic index was higher with GTPN than STPN. We concluded that Gln supplementation would prevent from leading the patients with severe infection to the multiple organ failure.


Assuntos
Glutamina/farmacologia , Infecções/imunologia , Infecções/metabolismo , Proteínas/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Ativação Linfocitária/efeitos dos fármacos , Masculino , Sistema Fagocitário Mononuclear/efeitos dos fármacos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
9.
Gan To Kagaku Ryoho ; 20(9): 1173-8, 1993 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-8333745

RESUMO

Between 1981 and 1991, we conducted 3 trials of surgical adjuvant therapy for esophageal carcinoma. The first randomized trial was pre- and post-operative radiotherapy, 30 Gray for preoperative therapy and 50 Gray for postoperative therapy. The 2nd trial was performed with postoperative radiotherapy and postoperative chemotherapy, 30 Gray for radiotherapy and cisplatin (CDDP, 50 mg/m2) plus vindesine (VDS, 3 mg/m2) for chemotherapy. The 3rd trial was postoperative chemotherapy (CDDP+VDS) and surgery alone. In the survival rate of the first trial, no significant difference was noted between the 2 groups (n = 20 and n = 16), while in the 2nd trial, the 5-year survival rate in the chemotherapy group (n = 12) was significantly longer (p = 0.017) than that of the radiotherapy group (n = 12). At the present time, the 3rd trial shows no significant difference in survival between patients with (n = 15) and without (n = 15) postoperative chemotherapy. Therefore, we are now performing a new randomized trial with surgery alone and postoperative chemotherapy using a more effective regimen (CDDP 80 mg/m2 + 5-FU 800 mg/m2). In the near future, the most effective therapy will be selected for individual patients with esophageal carcinoma, thanks to developments in clinical oncology, new anticancer drugs, drug delivery systems and molecular biology.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Esofágicas/cirurgia , Quimioterapia Adjuvante , Cisplatino/administração & dosagem , Terapia Combinada , Esquema de Medicação , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/radioterapia , Feminino , Fluoruracila/administração & dosagem , Humanos , Masculino , Dosagem Radioterapêutica , Taxa de Sobrevida , Vindesina/administração & dosagem
10.
Jpn J Clin Oncol ; 22(3): 172-6, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1518165

RESUMO

Thirty-nine patients with advanced measurable squamous cell carcinomas were treated with two or more courses of 70 mg cisplatin/m2 on day 1 and 700 mg infused 5-fluorouracil/m2 on days 1-5 every 21 days. The overall response rate was 35.9 (95% confidence limits, 24.8-55.1%). Responses were seen in primary sites in the esophagus of five patients, in the lung of seven, the liver of one and the mediastinal lymph nodes of one. The average response duration was 3.5 (range 1-12) mo for patients who achieved partial response. The average survival time after the first administration was 9.5 mo for patients who responded to the treatment whereas, for those who did not, it was 5.6 mo. The major form of toxicity was myelosuppression and there were six patients with grade 3 toxicity and one with grade 4. The present study was designed to evaluate the effectiveness of combined cisplatin and 5-fluorouracil for advanced squamous cell carcinoma, and the results showed that it had a reasonable effect and might possibly be used as a postoperative chemotherapy because of its mild side effects.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias Esofágicas/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Escamosas/mortalidade , Quimioterapia Adjuvante , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Avaliação de Medicamentos , Neoplasias Esofágicas/mortalidade , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Taxa de Sobrevida
12.
Endocrinology ; 122(2): 659-64, 1988 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3123202

RESUMO

To investigate the neural mechanism involved in suppression of GH secretion, we examined the effect of electrical stimulation of the midbrain central gray (CG) and several raphe nuclei on human (h) GRF-induced GH secretion in pentobarbital-anesthetized rats. A concentric bipolar stimulating electrode was implanted stereotaxically into each nucleus under pentobarbital anesthesia 1 week before stimulation. Blood samples were taken through a cannula placed in the right atrium via the right external jugular vein. Under pentobarbital anesthesia, 5 micrograms hGRF dissolved in 0.3 ml saline were systemically applied through this cannula. Ten minutes after the infusion, plasma GH was increased from the resting value of 28.5 +/- 7.1 ng/ml (mean +/- SE) to 686.1 +/- 62.0 ng/ml. Biphasic electrical stimulation was delivered for the first 10 min. When the CG was stimulated with a current of 500 microA, hGRF-induced GH secretion was markedly suppressed. However, even when the stimulation site was outside the CG, hGRF-induced GH secretion was suppressed. But with a smaller current (100 microA) the suppressive effect was observed only when the medial portion of the CG was stimulated. This suppression was abolished by prior lesioning of the hypothalamic periventricular nucleus (Pe), in which most of the somatostatin-immunoreactive fibers in the median eminence originate. The stimulation of the dorsal raphe with a current of 500 microA suppressed the GH increment at 10 min, but no suppression occurred with a current of 100 microA. This suppression was abolished by prior lesioning of the Pe. Electrical stimulation of the rest of the raphe nuclei had no effect on hGRF-induced GH secretion. These results suggest that electrical stimulation of the CG suppresses hGRF-induced GH secretion, and the most effective area is the ventromedial portion of the CG. These suppressive actions may be achieved by activation of the somatostatin neurons in the Pe.


Assuntos
Encéfalo/fisiologia , Hormônio Liberador de Hormônio do Crescimento/farmacologia , Hormônio do Crescimento/metabolismo , Núcleos da Rafe/fisiologia , Animais , Estimulação Elétrica , Eletrofisiologia , Hormônio do Crescimento/sangue , Hipotálamo/fisiologia , Masculino , Pentobarbital/farmacologia , Ratos , Valores de Referência
13.
Neuroendocrinology ; 46(4): 312-7, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3118229

RESUMO

Regulation of the pituitary-thyroid axis in rats with hypothalamic knife cuts has been studied. Complete hypothalamic deafferentation, either limited to the median eminence and the arcuate nucleus, or including parts of the dorsomedial nucleus and the whole ventromedial nucleus caused an increase in thyrotropin (TSH)-releasing hormone (TRH)-induced TSH secretion. Using an immunocytochemical procedure, a few TRH-positive fibers were observed within the median eminence of the larger island, while almost no fibers were identified in the smaller island. The exaggerated TSH response to TRH appeared within 3 days after the surgery and lasted for at least 1 week, when blood thyroxine (T4) level was significantly lowered. Exogenously injected T4 could inhibit such responses of TSH in the deafferented rats in a dose-related manner. These results support the hypothesis that the increase in the TSH response to TRH following hypothalamic deafferentation is due, at least in part, to the lowered thyroid hormone level in the blood.


Assuntos
Hipotálamo/fisiologia , Hormônio Liberador de Tireotropina/farmacologia , Tireotropina/sangue , Animais , Masculino , Ratos , Ratos Endogâmicos , Tri-Iodotironina/sangue , Tri-Iodotironina/farmacologia
14.
Acta Endocrinol (Copenh) ; 111(1): 25-9, 1986 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2868601

RESUMO

To delineate the site at which the central noradrenergic (NE) system may exert its stimulatory influence on the thyrotrophin (TSH) secretion, plasma TSH concentrations were measured before and after clonidine (an alpha 2-agonist) administration to the hypothalamus of unanaesthetized, unrestrained rats. When the animals received a simultaneous injection of clonidine (0.2 microgram) and phenoxybenzamine (2.0 micrograms) into the dorsomedial nucleus (DMN)/the paraventricular nucleus (PVN), a significant rise in TSH levels was observed. Injection of the mixture into the anterior hypothalamus, posterior hypothalamus, ventromedial hypothalamus, and arcuate nucleus had no influence on the plasma TSH concentration. Clonidine (10.0 micrograms/100 g body weight) and phenoxybenzamine (100 micrograms/100 g body weight) injected into the jugular vein also caused a prompt increase in the plasma TSH concentration. In rats with an intact small hypothalamic island, the TSH response to the iv injection of the drugs was considerably diminished. These data support the view that NE receptors in the DMN/PVN are of importance in exerting an NE-stimulatory influence on the TSH secretion, probably through the TRH neurons.


Assuntos
Agonistas alfa-Adrenérgicos/administração & dosagem , Clonidina/administração & dosagem , Hipotálamo/efeitos dos fármacos , Tireotropina/sangue , Antagonistas Adrenérgicos alfa/administração & dosagem , Animais , Masculino , Microinjeções , Fenoxibenzamina/administração & dosagem , Ratos , Ratos Endogâmicos , Ioimbina/administração & dosagem
15.
Endocrinology ; 116(1): 382-8, 1985 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3917251

RESUMO

The object of the present experiments was to clarify the topography of hypothalamic areas related to the suppression of GH release induced by human pancreatic GH-releasing factor (hpGRF). One week before the experiments, bipolar concentric stimulating electrodes were implanted in the organum vasculosum of the lamina terminalis (OVLT), the periventricular nucleus of the hypothalamus (Pe), the ventromedial nucleus of the hypothalamus (VMH), the lateral hypothalamic area (LHA), or the ventral premammillary nucleus (PMV). At the same time, the jugular vein was cannulated for blood sampling, and lesion of the anterior Pe was performed with a cathodal current. One and one half hours before the first blood sampling the rats were anesthetized with pentobarbital to prevent spontaneous GH bursts. One minute after the first blood sampling, 10 micrograms hpGRF dissolved in 0.3 ml saline was injected iv through the cannula. The blood samples were collected at 10, 20, 30, and 60 min after the zero-time sample. The above mentioned hypothalamic nuclei were electrically stimulated for the first 10 min. Injection of hpGRF increased the plasma GH level from 44.2 +/- 7.3 ng/ml (mean +/- SE) to 981.4 +/- 59.8 ng/ml in 10 min, and the plasma GH level gradually decreased to 50.8 +/- 8.8 ng/ml by 60 min. The hpGRF-induced GH release was most effectively suppressed by the stimulation of the Pe. After the stimulation of the OVLT, the VMH, the LHA, or the PMV, the suppression of hpGRF-induced GH release was weaker than that of the Pe. This stimulation-induced suppression was fully or partly prevented in Pe-lesioned animals. These results indicate that the stimulation of the Pe, the OVLT, the VMH, the LHA, or the PMV exerts an inhibitory effect on GH release. For this inhibitory effect, the Pe was essential. The results are discussed with regard to the topography of immunoreactive SRIF neuronal cell bodies and processes in the hypothalamus.


Assuntos
Hormônio Liberador de Hormônio do Crescimento/farmacologia , Hormônio do Crescimento/metabolismo , Hipotálamo/fisiologia , Animais , Estimulação Elétrica , Cinética , Masculino , Núcleo Hipotalâmico Paraventricular/fisiologia , Ratos , Ratos Endogâmicos , Núcleo Hipotalâmico Ventromedial/fisiologia
16.
Endocrinol Jpn ; 30(3): 397-403, 1983 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6141046

RESUMO

To determine the localization of the clonidine sensitive area responsible for GH release, a minute amount of the alpha 2-agonist (67 ng/0.2 microliter) was injected into the hypothalamus and vicinity of adult male conscious rats. The animals were chronically implanted with double metal cannulae fixed on the skull for clonidine microinjection and with silastic tubing into the right atria for collecting blood samples. Ten hr prior to the microinjection, alpha-methyl-p-tyrosine (250 mg/kg body weight) was intraperitoneally injected to prevent spontaneous pulsatile GH release. Localization of the microinjection was assessed by histological examination after the experiment. Clonidine microinjection into the amygdala nucleus had no effect on GH release, while the injection into the preoptic and anterior hypothalamic area (PO/AH) significantly stimulated GH release by causing it to begin 30 min earlier. However, the paraventricular nucleus, the dorsomedial nucleus, the lateral hypothalamus and the ventromedial hypothalamus areas did not respond to the injection, although the latter nucleus has been shown to be a specific locus sensitive to electrical stimulation of release. In the area from the posterior hypothalamus to the mammillary body, several injections stimulated GH release (6/15), but the stimulatory effect was statistically insignificant when comparison was made with the mean (+/- SE) for all 15 rats. These findings suggest that the alpha 2-agonist acts on the PO/AH to induce an increase in GH release in alpha-methyl-p-tyrosine-pretreated rats, probably mediating the inhibitory input to somatostatinergic neurons which reside in the periventricular nucleus of the PO/AH area.


Assuntos
Clonidina/farmacologia , Hormônio do Crescimento/metabolismo , Hipotálamo/fisiologia , Agonistas alfa-Adrenérgicos/farmacologia , Animais , Clonidina/administração & dosagem , Hipotálamo/efeitos dos fármacos , Hipotálamo Anterior/fisiologia , Masculino , Área Pré-Óptica/fisiologia , Ratos , Ratos Endogâmicos
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