Acciones óseas de las hormonas de la neurohipófisis / Bone actions of neuro hypophyseal hormones

La oxitocina (OXT) como la arginina-vasopresina (AVP) son dos hormonas primitivas secretadas por la hipófisis posterior. Sus receptores están mucho más ampliamente distribuidos en el organismo de lo que se pensaba originalmente, incluido el hueso. En los estudios preclínicos, la OXT ha mostrado ser anabólica para el hueso, promoviendo la osteogénesis sobre la adipogénesis y favoreciendo la actividad osteoblástica sobre la osteoclástica. Tanto los osteoblastos como los osteoclastos tienen receptores para la OXT, y los efectos de los estrógenos sobre la masa ósea en ratones está mediada por lo menos en parte por la OXT. El mecanismo preciso por el cual la activación de los receptores de oxitocina (OXTR) se traduce en un incremento de la formación ósea permanece poco claro. La AVP también podría afectar el esqueleto en forma directa. Dos de los receptores de la AVP, V1a y V2 están expresados en osteoblastos y osteoclastos. La inyección de AVP en ratones de tipo salvaje aumenta la formación osteoclastos que producen resorción y reduce los osteoblastos formadores de hueso. En forma opuesta, la exposición de precursores osteoblásticos a antagonistas de los receptores V1a o V2, incrementan la osteoblastogénesis, como también lo hace la deleción genética del receptor V1a. (AU)

Both oxytocin (OXT) and argininevasopressin (AVP) are primitive hormones secreted by the posterior pituitary gland. OXT receptors are much more widely distributed in the body than originally thought, including in bone. In preclinical studies, OXT has been shown to be anabolic for bone, promoting osteogenesis over adipogenesis and favoring osteoblastic over osteoclastic activity. Both osteoblasts and osteoclasts have receptors for OXT, and the effects of estrogen on bone mass in mice is mediated at least in part by OXT. The precise mechanism by which the activation of oxytocin receptors (OXTRs) results in an increase in bone formation remains unclear. AVP could also have direct actions on the skeleton. The two AVP receptors, V1a and V2, are expressed in osteoblasts and osteoclasts. Injection of AVP in wild-type mice increases the formation of osteoclasts increasing bone resorption, and reduces bone-forming osteoblasts. On the contrary, the exposure of osteoblastic precursors to V1a and V2 antagonists increase osteoblastogenesis, the same as the genetic deletion of the V1a receptor. (AU)

Treatment of septic shock in children with low dose pituitrin: report of 24 cases / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore the clinical effect of low dose pituitrin in children with septic shock.</p><p><b>METHODS</b>A total of 48 pediatric cases with septic shock, in whom 6 hours, conventional treatment could not reverse shock from January 2008 to December 2010, were selected for this study. The patients were divided into two groups randomly (completely random design) (control group 24, remedial group 24). The conventional treatment included antibiotics/fluid resuscitation/correcting acid-base imbalance, glucocorticoid, organ (heart/lung) support, dopamine 1 - 15 µg/(kg·min) and norepinephrine 0.5 - 2 µg/(kg·min) pumped in continuously in the control group. In initial 6 hours the same treatment was given to the remedial group, while low dose pituitrin (0.01 - 0.03 U/min) was pumped additionally during the rest of time. The therapeutic effect on correcting shock was evaluated in both groups.</p><p><b>RESULTS</b>The total effective rate was 76.2% in the remedial group and 40.0% in the control group; the mortality was 33.3% and 60% respectively. The difference between both groups was significant (P = 0.025).</p><p><b>CONCLUSION</b>Low dose pituitrin could improve the clinical effect significantly in children with septic shock in whom 6 hours conventional treatment failed to correct shock, shorten the total periods of treatment, and decrease mortality.</p>

Molecular analysis of PROP1, PIT1, HESX1, LHX3, and LHX4 shows high frequency of PROP1 mutations in patients with familial forms of combined pituitary hormone deficiency

Combined Pituitary Hormone Deficiency (CPHD) is a prevalent disease in Neuroendocrinology services. The genetic form of CPHD may originate from mutations in pituitary transcription factor (PTF) genes and the pituitary image in these cases may give a clue of what PTF is most probably mutated: defects in LHX4 are usually associated with ectopic posterior pituitary (EPP); defects in LHX3, PIT1, and PROP1, with normally placed posterior pituitary (NPPP); HESX1 mutations are associated with both. OBJECTIVE: To identify mutations in PTF genes in patients with idiopathic hypopituitarism followed in our service, based on the presence or absence of EPP on sellar MRI. METHODS: Forty patients with idiopathic hypopituitarism (36 families, 9 consanguineous), followed in the Neuroendocrinology Outpatient Clinic of UNIFESP, Brazil, were submitted to sequencing analyses of PTF genes as follows: LHX3, HESX1, PIT1, and PROP1 were sequenced in patients with NPPP (26/40) and HESX1 and LHX4 in patients with EPP (14/40). RESULTS: We identified only PROP1 mutations in 9 out of 26 patients with CPHD and NPPP (35 percent). Since eight of them came from 4 consanguineous families, the prevalence of PROP1 mutations was higher when only consanguineous families were considered (44 percent, 4/9). At the end of the study, we decided to sequence PROP1 in patients with EPP, just to confirm that they were not candidates for PROP1 mutations. No patients with EPP had PROP1 or other PTF mutations. CONCLUSIONS: Patients with idiopathic CPHD and NPPP, born from consanguineous parents, are the strong candidates for PROP1 mutations. Other developmental gene(s) may be involved in the genesis of idiopathic hypopituitarism associated with EPP.

Deficiência Combinada de Hormônios Hipofisários (DCHH) é uma doença prevalente em todos os serviços de Neuroendocrinologia. A DCHH de origem genética pode resultar de mutações nos genes de fatores de transcrição hipofisários (FTH), e a ressonância magnética (RM) de sela desses pacientes pode indicar qual FTH tem maior probabilidade de estar mutado: mutações no LHX4 estão geralmente associadas a neuro-hipófise ectópica (NHE); mutações no LHX3, PIT1 e PROP1, a neuro-hipófise tópica (NHT); mutações no HESX1 podem estar associadas a NHE e NHT. OBJETIVO: Identificar mutações nos FTH em pacientes acompanhados em nosso serviço, portadores de hipopituitarismo idiopático, selecionando os genes a serem estudados de acordo com a presença ou ausência de NHE à RM sela. MÉTODOS: Os genes dos FTH foram seqüenciados em 40 pacientes com hipopituitarismo idiopático (36 famílias, 9 consangüíneas), acompanhados na unidade de Neuroendocrinologia da UNIFESP, SP, Brasil: LHX3, HESX1, PIT1 e PROP1 foram seqüenciados nos pacientes com NHT (26/40) e HESX1 e LHX4, nos pacientes com NHE (14/40). RESULTADOS: Somente mutações PROP1 foram identificadas em 9 de 26 pacientes (35 por cento) com NHT, 8 deles provenientes de 4 famílias consangüíneas (4/9, 44 por cento). Uma vez que mutações no PROP1 foram tão freqüentes, decidimos, ao final do estudo, seqüenciá-lo também nos pacientes com NHE. Nenhum paciente com NHE apresentou mutações no PROP1 ou em outro FTH. CONCLUSÃO: Mutações no gene PROP1 foram encontradas em 22,5 por cento (9/40) de todos os pacientes, em 35 por cento (9/26) dos pacientes com NHT e em 44 por cento (4/9) se considerarmos somente as famílias consangüíneas. Portanto, pacientes com DCHH idiopática e NHT, provenientes de famílias de pais consangüíneos, são os melhores candidatos a mutações PROP1.

Study on free radical mechanism of guanxin II in antagonizing ischemic myocardial damage / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study comparatively the effect of Guanxin II and its constituents, including Salvia, Red Peony root, Chuanxiong, Safflower and Dalbergia wood, in scavenging active oxygen free radical (OFR) to explore their mechanism in overcoming the experimental acute ischemic myocardial injury and protecting myocardial tissue.</p><p><b>METHODS</b>The experimental acute myocardial ischemic model was established by intraperitoneal injection of pituitrin to rats. OFR level in animal heart tissue was directly measured with low-temperature electron paramagnetic resonance (EPR) spectrometer.</p><p><b>RESULTS</b>The pathological examination of HE stained slide of myocardial tissue and electrocardiography of model animal showed that typical changes of acute myocardial ischemia occurred in myocardial tissue, EPR showed that OFR level in myocardial tissue increased abnormally. The ethanol extract of Guanxin II and its constituents could lower the increased OFR level close to normal, thus to alleviate the myocardial damage.</p><p><b>CONCLUSION</b>Overproduction of OFR could induce damage of heart tissue, its level could be measured directly using low temperature EPR. One of the molecular mechanisms of Guanxin II and its constituents in antagonizing and repairing myocardial damage is to scavenge the abnormal increased active OFR in tissue. This study has provided a basis for further studying the mechanism of Chinese composite recipes and their constituents.</p>

Effect of ginsenoside Rg2 on chemical myocardial ischemia in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the protective effect of Ginsenoside Rg2 on Chemical myocardial ischemia.</p><p><b>METHOD</b>The models of myocardial ischemia were built in rats with isoproterenol, sodium nitrite,pituitrin. Ginsenoside Rg2 (iv 2.5, 5.0, 10.0 mg x kg(-1)) were intravenously administered.</p><p><b>RESULT</b>Ginsenoside Rg2 could improve the abnormal electrocardiogram (ECG), reduce the arca of myocardial ischemia and improve the abnormal zymologic value of myocardial.</p><p><b>CONCLUSION</b>Ginsenoside Rg2 has inhibitory function on myocardialischemia.</p>

Experimental study on effect of sini decoction on myocardial endothelin in myocardial ischemic rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the molecular mechanism of effect of Sini Decoction (SND) on myocardial endothelin (MET) in myocardial ischemic rats.</p><p><b>METHODS</b>Sprague-Dawley rats were randomly divided into 3 groups, the normal control group, the ischemia group and the SND group. Myocardial ischemia was produced by pituitrin in the latter two groups. The content, immunohistochemical assay and gene expression of MET-1 were determined in all the three groups and compared.</p><p><b>RESULTS</b>The content of MET in the SND group was significantly lower than that in the ischemia group (P < 0.01). Immunohistochemical examination showed that MET-1 was mainly located at the cardiac muscle cells and vascular endothelial cells with the grey scale obviously lower in the ischemia group than that in the control group and the SND group (P < 0.01). While RT-PCR showed that the grey scale of PCR product band in the ischemia group was significantly higher than that in the other two groups (P < 0.01).</p><p><b>CONCLUSION</b>SND could significantly lower MET content, it may be related to the effect of SND in inhibiting MET-1 gene expression and protein synthesis.</p>