Anatomical investigation of the measurements, shape and arterial irrigation of the adrenal gland in New Zealand rabbits / Investigação anatômica das medidas, forma e irrigação arterial da glândula adrenal em coelhos da raça Nova Zelândia

Rabbits have been used as an experimental model in many studies. These studies are important for not only for veterinary clinicians, but also for researchers in different elds. The aim of this research was to describe gross morphological measurement, shape and arterial supply of the adrenal glands in healthy New Zealand rabbits. Dissections were performed in 30 adult rabbits, 15 males and 15 females, without macroscopic adrenal pathology. Adrenal measurements were made with a digital caliper: length, width, and thickness. The origin of the adrenal arteries was also determined. Both adrenal glands were localized cranially to the respective kidneys. The mean of the right adrenal gland was 0.88 cm length, 0.42 cm width and 0.16 cm thickness; the left gland measured 0.72 cm, 0.46 cm, and 0.17 cm, respectively. The right gland was significantly more elongated than the left (p = 0.0003) and the means of the measurements did not differ between sexes. Most of the right adrenal glands had a piriform shape (73.3%), whereas most of the left gland exhibited a bean-shaped aspect (60.0%). The arterial supply was found to arise from different arteries:  lumbar, aorta, renal, caudal mesenteric, and testicular or ovarian. Comparatively, the descriptions of shape, position and arterial irrigation of the adrenal gland in rabbits are similar to those available in rodents. The data from the pres

Coelhos têm sido utilizados como modelo experimental em muitos estudos. Esses estudos são importantes não apenas para médicos veterinários, mas também para pesquisadores de diferentes campos. O objetivo desta pesquisa foi descrever as medidas morfológicas macroscópicas, forma e suprimento arterial das glândulas adrenais em coelhos saudáveis da raça Nova Zelândia. As dissecções foram realizadas em 30 coelhos adultos, 15 machos e 15 fêmeas, sem sinais macroscópicos de patologia adrenal. As medidas adrenais foram realizadas com paquímetro digital: comprimento, largura e espessura. A origem das artérias adrenais também foi determinada. Ambas as glândulas adrenais foram localizadas cranialmente nos respectivos rins. A média da glândula adrenal direita foi de 0,88 cm de comprimento, 0,42 cm de largura e 0,16 cm de espessura; a glândula esquerda mediu 0,72 cm, 0,46 cm e 0,17 cm, respectivamente. A glândula direita foi significativamente mais alongada que a esquerda (p = 0,0003) e as médias das medidas não diferiram entre os sexos. A maioria das glândulas adrenais direitas tinha uma forma piriforme (73,3%), enquanto a maioria da glândula esquerda exibia um aspecto em “forma de feijão” (60,0%). Verificou-se que o suprimento arterial provém de diferentes artérias: lombar, aorta, renal, mesentérica caudal e testicular ou ovariana. Comparativamente, as descrições de forma, posição e irrigação arterial da glândula adrenal em coelhos são semelhantes às disponíveis em roedores. Os dados da presente investigação ajudarão na interpretação de achados patológicos e / ou experimentais em coelhos da raça Nova Zelândia.

Uso racional de corticoides en el paciente con shock séptico / Rational use of corticoids in a patient with septic shock

Introduction: Septic shock (SS) is a significant cause of mortality in NICUs. Objective: Review current knowledge on Hypothalamic-Pituitary-Adrenal Axis (HPA) and the scientific support for the use of gluco-corticoids in the use of this clinical picture. We know that the patient's ability to evolve into improvement or worsening depends upon the ability of the HPA axis to develop and sustain an adequate response to the stress provoked by SS. In some patients, due to many reasons, the prolongation of SS leads to a deficit of cortisol those results in functional acute adrenal insufficiency. Cortisol levels do not respond to ACTH stimulation test. There is no consensus among authors as to what is a normal concentration of cortisol during stress, or even if it is correlated with death among children with SS. The American College of Critical Care Medicine guidelines for SS in Pediatrics and Neonatology have made some recommendations for use of hydrocortisone.

Introducción: El shock séptico (SS) es una de las mayores causas de mortalidad en unidades de cuidados intensivos pediátricas. Objetivo: Revisar qué sabemos hasta ahora del papel que juega el eje hipotálamo-pituitaria-adrenal (HPA) en el SS y si hay evidencia científica que apoye el uso de glucocorticoides en el transcurso de este cuadro. Sabemos que de la habilidad del eje HPA para montar y sostener en el tiempo una adecuada respuesta al stress provocado por un SS dependerá si el paciente evoluciona a la mejoría o se agrava. En algunos pacientes debido a múltiples mecanismos, la prolongación del SS puede llevar a un déficit de cortisol, resultando en una insuficiencia adrenal aguda o funcional, la que se reflejaría en que los niveles de cortisol no responderían con un incremento significativo frente a una prueba de estimulo con ACTH. Entre los diversos reportes revisados, no existe consenso sobre cual sería la concentración "normal" de cortisol durante el stress y más aun no está claro si esto se correlacionaría con la mortalidad en el caso de los niños. Las guías de shock séptico en pediatría y neonatología del American College of Critical Care Medicine recomiendan en que tipo de pacientes con SS se debiera considerar tratamiento con hidrocortisona.

Adrenal insufficiency.

Adrenal insufficiency can be due to disease of the adrenal gland itself (primary adrenal deficiency) or of the hypothalamic or pituitary regulation of the adrenal gland (secondary adrenal insufficiency). This article discusses its causes, clinical features, diagnosis and treatment.

Adrenal hypersecretion.

Hypersecretion from the adrenal glands is associated with hypertension. Causes include Conn syndrome, Cushing syndrome and phaechromocytoma. This article discusses their clinical features, diagnosis and treatment as well as the management of incidentally identified adrenal tumours (incidentaloma).

The adrenal glands and their functions.

The adrenal glands secrete hormones essential for metabolism, regulation of blood pressure, and sodium and glucose homeostasis. Hypo- or hypersecretion of these hormones is life threatening. Understanding the physiological functions of adrenal hormones is a prerequisite to the management of adrenal gland disease.

A connection between extracellular matrix and hormonal signals during the development of the human fetal adrenal gland

The human adrenal cortex, involved in adaptive responses to stress, body homeostasis and secondary sexual characters, emerges from a tightly regulated development of a zone-specific secretion pattern during fetal life. Its development during fetal life is critical for the well being of pregnancy, the initiation of delivery, and even for an adequate adaptation to extra-uterine life. As early as from the sixth week of pregnancy, the fetal adrenal gland is characterized by a highly proliferative zone at the periphery, a concentric migration accompanied by cell differentiation (cortisol secretion) and apoptosis in the central androgen-secreting fetal zone. After birth, a strong reorganization occurs in the adrenal gland so that it better fulfills the newborn's needs, with aldosterone production in the external zona glomerulosa, cortisol secretion in the zona fasciculata and androgens in the central zona reticularis. In addition to the major hormonal stimuli provided by angiotensin II and adrenocorticotropin, we have tested for some years the hypotheses that such plasticity may be under the control of the extracellular matrix. A growing number of data have been harvested during the last years, in particular about extracellular matrix expression and its putative role in the development of the human adrenal cortex. Laminin, collagen and fibronectin have been shown to play important roles not only in the plasticity of the adrenal cortex, but also in cell responsiveness to hormones, thus clarifying some of the unexplained observations that used to feed controversies.

Metallothionein in male reproductive organs of adrenalectomized and hydrocortisone-treated Wistar rats.

Adrenalectomy resulted in an increase in metallothionein (MT) levels in testes, caput and cauda epididymis and prostate of rats but not in seminal vesicles where its levels decreased significantly. Inspite of administration of hydrocortisone, MT in testes, prostate (1.2 mg), caput (0.3 mg days 2, 8; 0.6 mg and 1.2 mg) and seminal vesicles (0.3 mg day 2, 4; 0.6 mg and 1.2 mg) remained increased. Thus adrenal insufficiency/hydrocortisone has no direct influence on MT levels. However, the increased levels of MT can be related to its ability to protect the cells from free radical damage caused by atrophy of reproductive tissues in adrenalectomised rats. Exogenously administered hydrocortisone to ADX rats resulted in return to ADX state as hydrocortisone metabolizes (half-life < 12 hr) and hence MT levels remained increased. The observations could provide a clue for the physiological functioning of the male reproductive tissue in a state of adrenal deprivation and hormonal supplementation.

Microscopical study on the age related changes in the adrenal gland of male albino rat

In this work, twenty-four male albino rats were studied at [5-6] months of age [adult group] and at [23-24] months [aged group]. Light microscopic examination of aged animals revealed degenerative changes in some cells of zona fasciculata together with mononuclear cellular infiltration. Areas of necrosis were detected in zona fasciculata of some animals. Dilatation and congestion of sinusoidal capillaries were seen in zona fasciculata. Nodule like structures were detected among the cells of zona fasciculata of some animals. Marked increase in ascorbic acid and lipid contents was detected in inner cortical zone. In adrenal medulla, there was an apparent decrease in the number of norepinephrine secreting cells. Morphometric study revealed a significant increase in the mean thickness of zona fasciculata of the aged animals. Ultrastructural study showed that some cells of zona fasciculata of the aged animals had irregular nuclei. Disruption and loss of inner mitochondrial structure were seen in some zona fasciculata cells. In adrenal medulla, norepinephrine secreting cells showed degenerative change with decrease in the number of secretory granules

Involvement of adrenal and thyroid activity in the annual testicular regression of red headed bunting (Emberiza bruniceps).

Thyroid and adrenal activities are closely associated with reproductive cycle and any alteration in these endocrine functions may cause changes in the pituitary-gonadal axis.To understand this interrelationship during testicular senstive phase (month of April) male birds were injected with metapyrone(corticosterone synthesis blocks 1 microg/bird/day & 10 microg/bird/day) and newmercazol (thyroxine synthesis blocks 10 microg/bird/day) over a period of 12 weeks.During late breeding phase (month of August) two sets of birds having large gonad (photosensitive) and regressed gonad (photorefractory) were injected with metapyrone (10 microg/bird/alternate day). Results indicate that decreased activity of both adrenal and thyroid, extended the breeding phase but rate of regression decreased only in the case of bird receiving higher level of metapyrone.However,in the second group rate of gonadal regression was slow only in those bird where treatment was started during photosensitive phase. It may be suggested that optimum level of activity of adrenal and thyroid function are essential for termination of reproduction and any alteration in these function may alter seasonal pattern of neuroendocrine gonadal axis.

The neuroimmune-endocrine axis: pathophysiological implications for the central nervous system cytokines and hypothalamus-pituitary-adrenal hormone dynamics

Cytokines are molecules that were initially discovered in the immune system as mediators of communication between various types of immune cells. However, it soon became evident that cytokines exert profound effects on key functions of the central nervous system, such as food intake, fever, neuroendocrine regulation, long-term potentiation, and behavior. In the 80's and 90's our group and others discovered that the genes encoding various cytokines and their receptors are expressed in vascular, glial, and neuronal structures of the adult brain. Most cytokines act through cell surface receptors that have one transmembrane domain and which transduce a signal through the JAK/STAT pathway. Of particular physiological and pathophysiological relevance is the fact that cytokines are potent regulators of hypothalamic neuropeptidergic systems that maintain neuroendocrine homeostasis and which regulate the body's response to stress. The mechanisms by which cytokine signaling affects the function of stress-related neuroendocrine systems are reviewed in this article.

Shen (rins) e a supra-renal / Shen (kidneys) and the adrenal gland

Foram relacionados os conceitos científicos da Medicina Ocidental sobre a embriologia e a fisiologia dos rins com as da supra-renal e estes com as concepçöes energéticas do Shen (Rins). Foi deduzido que a supra-renal exerce funçäo de Rim-Yang ativando o Rim-Yin através de vários hormônios secretados pelo córtex supra-renal, principalmente a aldosterona, o cortisol e os androgênios, promovendo ao Shen as funçöes de regularizaçäo do metabolismo da Agua, da termogênese e do desenvolvimento sexual. Por outro lado, a secreçäo da renina-angiotensina ao nível dos rins é um dos responsáveis pela relaçäo Alto/Baixo por meio do estímulo que exerce sobre o hipotálamo e sua conseqüente resposta pela hipófise promovendo a eliminaçäo de ACTH e sua açäo sobre a supra-renal e desta sobre os rins, assim como a influência do hipotálamo sobre a medula supra-renal, por meio do sistema vegetativo simpático, com a liberaçäo das catecolaminas.

Atrial natriuretic peptide and feeding activity patterns in rats

This review presents historical data about atrial natriuretic peptide (ANP) from its discovery as an atrial natriuretic factor (ANF) to its role as an atrial natriuretic hormone (ANH). As a hormone, ANP can interact with the hypothalamic-pituitary-adrenal axis (HPA-A) and is related to feeding activity patterns in the rat. Food restriction proved to be an interesting model to investigate this relationship. The role of ANP must be understood within a context of peripheral and central interactions involving different peptides and pathways.

Consideraciones etiológicas y fisiopatológicas en el síndrome del ovario poliquístico y los mecanismos de anovulación / Etiologic and physiopathology considerations in the policystic ovary syndrome and anovulation mechanism

El síndrome del ovario poliquístico es una entidad que ha causado gran interés por su frecuencia, por la controversia acerca de su origen y por las repercusiones que conlleva. El estado de anovulación crónico es la vía a través de la cual se originan las alteraciones morfológicas y endocrinas del síndrome, produciendo un complejo sintomático muy variable. Dentro de las alteraciones hormonales más importantes están un hiperandrogenismo y un estado estrogénico aumentado y no antagonizado. Nuestro intés estriba en revisar los factores etiológicos y fisicopatológicos de este síndrome, así como los mecanismos de anovulación implicados

Role of adrenal in establishment and development of conceptus in unilaterally ovariectomized mated rats.

The model of unilateral ovariectomy induced ovarian compensatory hypertrophy in mated bilaterally adrenalectomized rats was used to assess the role of adrenal in conceptus development. Replacement dose of dehydroepiandrosterone (DHA) or corticosterone (Comp. B) from day 2-14 post coitum was given with or without ip injections of estrogen (E, on day 2) and progesterone (P, on day 3 or 3-9). Replacement of adrenal hormones failed to support ipsilateral uterine horn (IP) pregnancy. But injections of E2 and P support IH pregnancy in variable percentages (about 38-75%) of rats depending on the type of adrenal steroids and single or multiple doses of P. Contralateral horn (CH) pregnancy developed under any of these conditions. Adrenalectomy induced reduction of fetal weight and pregnancy index (No. of fetus divided by No. of implantation sites), were not significantly improved by adrenal hormone replacement, except pregnancy index of those animals which received Comp. B and P. Adrenalectomy inhibited compensatory increase of contralateral corpus luteum (CL) volume and ovarian delta 5(3)beta-hydroxy steroid dehydrogenase (delta 5(3)beta-HSD) activity. Replacement of DHA or Comp. B induced these compensatory changes. Comp. B and P appears to be a better combination in establishment of IH pregnancy, pregnancy index maintenance and stimulation of ovarian compensatory changes. Results suggest that adrenocorticoids were not obligatory for conceptus development but were important for efficient action of ovarian steroids in establishment and maintenance of pregnancy. Relationship between nutrition or pituitary gonadotropins and adrenal steroids, having relevance to conceptus development has been discussed.

Endocrinología en las grandes alturas / Endocrinology at high altitude

El vivir en las grandes alturas, significa someterse a un medio donde predomina una baja presión de oxígeno. Ante tal situación el organismo responde en diversas formas para obtener una adaptación a este medio hipóxico. Estas respuestas pueden ser diferentes de acuerdo a la magnitud de la hipoxia. El estudio de la fisiología de altura, realizado por destacados científicos peruanos se ha constituido en uno de los más importantes campos de investigación en nuestro país en los últimos cincuenta años. En la presente revisión se ha tratado de resumir los trabajos sobre endocrinología en el nativo de la altura, que han realizado diversos investigadores del país y del extranjero, y se ha tratado de explicar en lo posible, las diferencias observadas con respecto a la endocrinología del nativo del nivel del mar. Los resultados demuestran diferencias endocrinas en el nativo de la altura, que están relacionados principalmente en el metabolismo intermedio, y en la reproducción

Influence of anterodorsal thalamic nuclei on adrenal function in rats

La estimulación bilateral de lo núcleos anterodorsales talámicos (NADT) produjo una significativa disminución en la concentración de corticosterona plasmática y adrenal. Las ratas con lesión bilateral de NADT mostraran una mayor respuesta de corticosterona plasmática al estrés agudo que las ratas control (falsa lesión). Las ratas controles estresadas presentan valores de cortiscosterona adrenal más altos que las no estresadas mientras que en las lesionadas estresadas los valores fueron significativamente más bajos que en las lesionadas no estresadas. Las concentraciones de catecolaminas adrenalaes, Noradrenalina (NA) y Adrenalina (A), en las ratas control no se modifcan por el estrés. En las ratas lesionadas estresadas las glándulas adrenales contienen cuatro veces más de NA y dos veces más de A que las glándulas adrenales de las lesionadas no estresadas

El concepto actual del sistema renina-angiotensina / Current concept of the renin-angiotensin system

El concepto tradicional del sistema renina-angiotensina (SRA) es el de un sistema andocrino que juega un papel central en el balance de agua y electrólitos y en la homeostasis de la presión arterial. El angiotensinógeno y la renina, secretados por el hígado y el riñón, respectivamente, interactúan para formar angiotensina l, la cual, a su vez, es hidrolizada por la enzima convertidora de angiotensina l para formar el péptido biológicamente activo del sistema, angiotensina II. Debido a que esta última enzima se localizó primero en la vasculatura pulmonar, se pensó que la angiotensina II se producía sólo en ese sitio y que posteriormente llegaba a sus órganos blanco por medio de la circulación. Sin embargo, gracia al desarrollo de nuevas técnicas bioquímicas y de biología molecular se ha podido documentar la presencia de los componentes del SRA, incluyendo sus ácidos ribonucleicos mensajeros (ARNm), en múltiples tejidos como riñón, vasos sanguíneos, corazón, cerebro y glándulas adrenales, entre otros. La presencia de los ARNm sugiere fuertemente que las proteínas del SRA se sintetizan localmente. Esto ha llevado a proponer que el SRA puede tener funciones paracrinas, autocrinas, e incluso intracrinas, además de las endocrinas ya bien conocidad, es decir, que el SRA puede estar involucrado en alguna función específica de cada tejido. Estos datos amplían el concepto tradicional del SRA ya que, además de su amplia distribución, se ha comprobado que solo SRA locales se regulan independientemente del sistema circulante. Por otra parte, estudiando el comportamiento de los SRA circulante y tisular ante diferentes situaciones patológicas como la hipertensión, se ha propuesto que la principal función del SRA circulante es mantener la homeostasis cardiorrenal a corto plazo, y que el control tónico de la resistencia vascular y de la función tisular local(por ejemplo, en adrenal y riñón) está reculada por los SRA locales. Finalmente, estas observaciones demuestran que el SRA tisular tiene un papel muy importante al igual que el SRA circulante.

Studies on testosterone level in female mature rabbits

This work was done to investigate the presence and origin of testosterone [T]T in the plasma of female mature rabbits. T was found to be present in a concentration of 0.129 ng/100 ml plasma. Intravenous [IV] injection of human chorionic gonadotropin [HCG] in a dose of 1000 IU resulted in a significant increase [P < 0.001 and P < 0.05] in plasma T level I and 6 hours after HCG injection. The level returned to the control value 10 hours after the injection. To study the origin of T in female rabbits bilateral ovariectomy was done in one group of rabbits and bilateral adrenalectomy was done in another group. In both groups, plasma T level significantly decreased [P < 0.05 and P < 0.001] 2 and 4 hours respectively after the operation. This indicates that both the ovaries and adrenals are important source for T production in mature female rabbits