Amylase in the thyroid gland

Summary Amylase activity detected in thyroid extracts was significantly higher than that of normal sera. A starch film technique revealed the existence of amylase activity in the follicular lumen and on the follicular epithelia. By electrophoretic analysis of thyroid extracts, 4 bands of amylase activity were observed, one being of the same mobility as parotid and the other 3 more anodic. Amylase extracted from the thyroid appeared in the same position as pancreatic or parotid amylase on Sephadex G75 gel filtration. The possibility is discussed that the thyroid may synthesize amylase of salivary type, which is secreted from the follicular epithelia into the follicular lumen, where it may be transformed into anionic forms.     

Amylase in the thyroid gland

Amylase activity detected in thyroid extracts was significantly higher than that of normal sera. A starch film technique revealed the existence of amylase activity in the follicular lumen and on the follicular epithelia. By electrophoretic analysis of thyroid extracts, 4 bands of amylase activity were observed, one being of the same mobility as parotid and the other 3 more anodic. Amylase extracted from the thyroid appeared in the same position as pancreatic or parotid amylase on Sephadex G75 gel filtration. The possibility is discussed that the thyroid may synthesize amylase of salivary type, which is secreted from the follicular epithelia into the follicular lumen, where it may be transformed into anionic forms.     

Tumor immunity in the mammary gland

Summary Mouse mammary tumor 410, which was derived from a spontaneously arising BALB/cf C3H mammary tumor, grows better in syngeneic BALB/c mice after injection into mammary fatpads than after injection into subcutaneous sites. This finding is consistent with the notion that the fatpad is an imunologically privileged site. However, no evidence that the mammary fatpad was immunologically privileged with respect to tumor transplantation antigens was found. Tumor cells were injected into mammary fatpads or SC. When the tumors became palpable they were surgically removed. One to three weeks later, the mice were challenged on the opposite side by injection of tumor cells either SC or into the mammary fatpad. The mice were immune after temporary growth of tumors either in the fatpad or SC. Regardless of the growth site of the immunizing tumor, the mice rejected the challenge tumor cells whether they were injected SC or into the fatpad.     

Cholinergic nerves in the thyroid gland

Summary The cholinergic innervation of the thyroid gland has been studied in the human. AChE positive nerve fibers are localized in the wall of the thyroid artery, arranged in two plexuses, a superficial (adventitial) and a deep one (medial). The glandular tissue is provided with cholinergic nerve fibers, localized between and around thyroid follicles. The present results suggest that the endocrine activity of the thyroid gland is also under the control of the autonomic nervous system.     

Cre-mediated recombination in the pituitary gland

Organ-specific expression of a cre recombinase transgene allows for the analysis of gene function in a particular tissue or cell type. Using a 4.6 kb promoter from the mouse glycoprotein hormone alpha-subunit (alphaGSU or Cga) gene, we have generated and characterized a line of transgenic mice that express cre recombinase in the anterior and intermediate lobes of the pituitary gland. Utilizing a cre-responsive reporter transgene, alphaGSU-cre transgene expression was detected in the pituitary primordium and in all five cell types of the adult anterior pituitary. alphaGSU-cre transgene activity was also detected in the cardiac and skeletal muscle. Little or no activity was evident in the gonads, adrenal glands, brain, ventromedial hypothalamus, or kidneys. The alphaGSU-cre transgenic mice characterized here will be a valuable tool for examining gene function in the pituitary gland.     

Oxygen consumption in the parotid gland

Carbachol, substance P and epinephrine, but not isoproterenol, transiently stimulated O₂ consumption by 40–50% in rat parotid gland slices. The response to carbachol, but not to substance P, was blocked by atropine. Ouabain (1 mM) did not affect the response to carbachol. Also, the response to carbachol did not require external Ca, and was not significantly diminished by 1.0 mM LaCl₃. Reintroduction of Ca to a low Ca medium increased O₂ consumption only if carbachol was present. Procaine inhibited the increase in O₂ consumption due to carbachol, but not that due to substance P. When both carbachol and substance P were presented to the tissues in series and in the absence of external Ca, the second agonist failed to produce a response. When these results are considered in the light of previous studies on Ca and the responses of the parotid gland, they suggest that the primary stimulus for the O₂ consumption is the release of a limited pool of membrane-bound Ca following receptor activation.     

Information networks in the mammary gland

Unique developmental features during puberty, pregnancy, lactation and post-lactation make the mammary gland a prime object to explore genetic circuits that control the specification, proliferation, differentiation, survival and death of cells. Steroids and simple peptide hormones initiate and carry out complex developmental programmes, and reverse genetics has been used to define the underlying mechanistic connections.     

Enlightening the adrenal gland

The secretion of glucocorticoid hormones is tightly regulated by the circadian clock and by negative humoral feedback loops, both acting on the hypothalamic-pituitary gland-adrenal axis. However, a new study Ishida et al., 2005 [this issue of Cell Metabolism) shows that light can influence the adrenal's glucocorticoid output by a more direct pathway.     

The interaction of the thyroid gland, pineal gland and immune system in chicken

The interaction of immunological system, thyroid and pineal gland was studied in 5-week old males of Gallus domesticus. Several morphometrical parameters in pineal and thyroid glands were measured after bird immunization with human red blood cells and/or treatment with melatonin or seduxen, melatonin receptor blocker. The peak of the thyroid activity was found on Day 7 after immunization. The immune system appears to directly activate the thyroid gland only in the presence of certain level of melatonin. We suggest that the melatonin mechanism of action includes the enhancement of thyroid gland sensitivity to immune factors. Seduxen prevented the stimulatory influence of the immune system on the thyroid gland.     

Immunohistochemical evidence for the presence of melatonin in the pineal gland,the retina and the Harderian gland

Summary The presence of melatonin is demonstrated in the pineal gland, the retina and the Harderian gland in some mammalian and non-mammalian vertebrates, using a specific fluorescence labelled antibody technique. Four different potent antibodies against melatonin have been used and compared. In the pineal gland of hamsters, mice, rats and snakes, specific fluorescence, mostly restricted to the cytoplasm of the cells, is detected in pinealocytes. Fluorescence is also detected in the pineal organ of fishes, tortoises and lizards, but it has not been possible, from cryostat sections of fresh tissue, to assert which kind of cell is reacting (photoreceptor cells or interstitial ependymal cells). In the retina, fluorescence is almost exclusively restricted to the outer nuclear layer. In the Harderian gland of mammals and reptiles, fluorescence is localized in the secretory cells of the alveoli and mostly restricted to the cytoplasm surrounding the nucleus. These results are discussed in relation to the concept of melatonin synthesis at extrapineal sites independent of pineal production.Parts of this work have been presented in the Xth Conference of Comparative Endocrinologists, Sorrento, May 20–25, 1979 (Vivien-Roels and Dubois 1980) and the VIth International Congress of Endocrinology, Melbourne, February 10–16, 1980 (Vivien-Roels et al. 1980)The author wishes to thank Professor Lutz Vollrath who has accepted her in his laboratory for a short period, Doctor George M. Bubenik for his suggestions and critical remarks, Dr. L.J. Grota for producing the melatonin diazobenzoic acid-BSA and Dr. Castro for preparing one of the melatonin derivates