Response of host embryonic chicks to grafts of additional adrenal glands

Summary The ultrastructure of the developing adrenal gland of the chick has been studied over the embryonic period 10 to 18 days.Cortical cells occur in double-rowed strands, are loosely attached in early development but more firmly attached later in development. Hypertrophy of mitochondria, endoplasmic reticulum, golgi body, lipid and vacuoles increases with increasing age. Two cell types (designated Dark and Light) were present at 17 days of incubation. Their significance is discussed.Medullary cells occur as single cells at 10 days but more usually in groups by 18 days. Catecholamine-containing granules are a prominent feature of the medullary cells, at all ages. Two cell types could be distinguished in the medulla at 17 days of incubation. These may represent adrenalin and noradrenalin-containing cells.Changes in the ultrastructure of host adrenal glands after exposure to an 18 day adrenal gland, grafted onto the host chorio-allantoic membrane at 8 days, were studied. The chief response within the cortex of the host involved retardation of organelle hypertrophy, so that 17 day hosts resembled 14 day controls. More light cells were seen in the host than in the control cells. The medullary tissue of the host was also retarded in development and the release of catecholamine-containing granules inhibited. The significance of these observations in relation to compensatory hypertrophy within the host is discussed.Supported by National Research Council of Canada Grant No. A 5056, and by a Dalhousie University Research Development Grant. HPH is a Post Doctoral Research Fellow, supported under Grant A 5056.     

Regulation of dopamine beta-hydroxylase in rat adrenal glands.

Rat adrenal gland levels of dopamine beta-hydroxylase are subject to dual control. Activation of the splanchnic nerves to the adrenal medulla by reserpine induces the synthesis of dopamine beta-hydroxylase without altering the rate of enzyme degradation. In contrast, hypophysectomy causes a decline in steady state dopamine beta-hydroxylase levels by first accelerating the rate of degradation, then by slowing the rate of enzyme synthesis as well. Adrenocorticotropic hormone administration partially reversed the effect of hypophysectomy on dopamin beta-hydroxylase degradation. These findings suggest that the trans-synaptic factors controlling dopamine beta-hydroxylase induction act by a different mechanism (enzyme synthesis) than the hormonal controls regulating steady state levels (enzyme degradation). Thus, active inhibition of enzyme degradation may be an important control in maintenance of steady state enzyme levels.     

Operations on the adrenal glands

Various conditions of the adrenal gland are amenable to surgical treatment. Removal of a pheochromocytoma is almost always indicated when the tumor is diagnosed. The results of extirpation have been excellent in cases in which patients were operated upon before the onset of chronic hypertension. Removal of the "nerve cell" tumors of the adrenal is indicated if metastasis cannot be demonstrated. Hypofunction of the adrenal cortex may be partially alleviated by the repeated implantation of pellets of desoxycorticosterone acetate. Hyperfunction of the adrenal cortex causes a variety of clinical manifestations depending upon which of the numerous hormones are affected. Removal of a cortical tumor alleviates these symptoms. These tumors are malignant in more than 50 per cent of cases, and recurrence is frequent. Bilateral hyperplasia of the glands rather than a tumor may be present. In such circumstances, resection of 95 per cent of the adrenal tissue is effective in controlling the symptoms of the disease. Total bilateral excision of the adrenals is, at present, under investigation as a means of treatment for a variety of conditions.     

Localized non-Hodgkin's lymphoma of the adrenal and thyroid glands.

A case of immunoblastic lymphoma, involving only the thyroid and the adrenal glands, is presented. The patient had clinical symptoms and findings of Addison's disease, and computed tomography (CT) demonstrated bilateral adrenal tumoral enlargement. He also had euthyroid diffuse multinodular goiter. The diagnosis of the patient was based on the cytological examination of the aspiration materials from both endocrine glands. The patient received "m-BNCOD" chemotherapy regimen and replacement therapy for Addison's disease. At the end of three courses, a partial response was obtained.     

Response of solitary adrenal gland to surgical stress

Synopsis Available reports on adrenal function following unilateral adrenalectomy mainly concern the gland's activity under basal conditions. Its response to superadded stress has largely escaped attention. The present communication deals with changes in morphology and in the behaviour of acid phosphatase, non-specific esterases and₃-hydroxysteroid dehydrogenase in solitary adrenal glands following operative trauma. Histochemical, electrophoretic and biochemical techniques have been employed in the study.Although the morphological response to identical trauma on both unilaterally adrenalextomized and intact animals is indistinguishable, the enzymological response is strikingly different in the two groups. While in the latter, the enzyme activities exhibit an early rise following trauma, the same is delayed by another 8 hr in the former. In experiments using ACTH, the overall pattern of esterase activity shows little deviation from that observed in untreated cases in both groups of animals.The findings indicate that in unilaterally adrenalectomized animals, superadded operative stimuli fail to evoke the early response characteristic of the normal adrenal glands. Such latency points to the vulnerability of their esisting defence mechanisms. The remarkable similarity of adrenal response with or without exogenous ACTH in these animals suggests that the reason for a delayed response is rooted in the target organ itself, and is not due to an altered plasma ACTH level.     

Identification of dinucleoside polyphosphates in adrenal glands

Dinucleoside polyphosphates have been characterised as extracellular mediators controlling numerous physiological functions like vascular tone or cell proliferation. Here we describe the isolation and identification of dinucleoside polyphosphates Ap(n)A (with n=2-3), Ap(n)G (with n=2-6) as well as Gp(n)G (with n=2-6) from adrenal glands. These dinucleoside polyphosphates are localised in granules of the adrenal glands. The dinucleoside polyphosphates diadenosine diphosphate (Ap(2)A), diadenosine triphosphate (Ap(3)A), adenosine guanosine polyphosphates (Ap(n)G) and diguanosine polyphosphates (Gp(n)G), both with phosphate group (p) numbers (n) ranging from 2 to 6, were identified by fractionating them to homogeneity by preparative size-exclusion- and affinity-chromatography as well as analytical anion-exchange and reversed-phase-chromatography from deproteinised adrenal glands and by analysis of the homogeneous dinucleoside polyphosphates containing fractions with post-source-decay (PSD) matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS). The identity of the dinucleoside polyphosphates was confirmed by retention time comparison with authentic dinucleoside polyphosphates. Enzymatic analysis demonstrated an interconnection of the phosphate groups with the adenosines in the 5(')-positions of the riboses in all dinucleoside polyphosphates purified from adrenal glands. In conclusion, the identification of these dinucleoside polyphosphates in adrenal gland granules emphasises that these dinucleoside polyphosphates can be released from the adrenal glands upon stimulation into the circulation.     

The importance of adrenal glands in the improved adaptation of trained animals to physical exertion.

The importance of adrenal glands in the adaptation of rats to physical exertion was studied. Exercise training, significantly increased the working ability and prevented the water accumulation in myocardial cells during acute exertion. The latter shift was characteristic of untrained animals. However, adrenalectomy abolished the benefical effect of training on working ability and myocardial adaptation to exertion. The results obtained supported the view that the effect of training is partly mediated through the improved adrenocortical function while adrenal hormones, by regulating the heart metabolism and function, significantly influenced the adaptation of rats to physical exertion.