Effects of thyroxine and exercise on the glandular and plasma levels of corticosterone in the male rat

Summary The results presented here demonstrates that the thyroid gland is essential for normal corticosterone production. They further show that exercise stimulates this production whether the thyroid gland is present or not. The release or metabolism of corticosterone seems dependent upon an intact thyroid gland since plasma levels of corticosterone are decreased during exercise if the thyroid is absent. The administration of thyroxine is not sufficient to renew these levels.     

Have we underestimated the importance of the thymus in man?

Summary Recent immunological research has concentrated on the complex and subtle interactions between T cells, B cells and accessory cells. In these studies, little attention has been given to the adult thymus gland. Modern textbooks of disease and anatomy all stress that the gland undergoes fatty involution with age in man but omit reference to the statements here and there in the literature that the gland is active and produces lymphocytes throughout life. To suggest that the bone marrow, which also builds up fat throughout life, is atrophic and not important to adult man would deny all modern hematological concepts. Yet few people today take a parallel view of the thymus except perhaps those investigating aging and thymic hormones. In both of these areas of research it is obvious that the thymus must be active throughout life for continued good health. This brief review urges that a thorough understanding of the vital importance of the thymus in adult life is now needed. From it could emerge a new philosophy on the treatment of immune diseases in both the young (SCID and AIDS patients) and in the aged (autoimmune conditions and cancers) and it would aid our treatment of patients recovering from illnesses and from many drug treatments.     

Have we underestimated the importance of the thymus in man?

Recent immunological research has concentrated on the complex and subtle interactions between T cells, B cells and accessory cells. In these studies, little attention has been given to the adult thymus gland. Modern textbooks of disease and anatomy all stress that the gland undergoes fatty involution with age in man but omit reference to the statements here and there in the literature that the gland is active and produces lymphocytes throughout life. To suggest that the bone marrow, which also builds up fat throughout life, is atrophic and not important to adult man would deny all modern hematological concepts. Yet few people today take a parallel view of the thymus except perhaps those investigating aging and thymic hormones. In both of these areas of research it is obvious that the thymus must be active throughout life for continued good health. This brief review urges that a thorough understanding of the vital importance of the thymus in adult life is now needed. From it could emerge a new philosophy on the treatment of immune diseases in both the young (SCID and AIDS patients) and in the aged (autoimmune conditions and cancers) and it would aid our treatment of patients recovering from illness and from many drug treatments.     

Increased melatonin levels after hemorrhagic shock in male and female C3H/HeN mice

Although hemorrhagic shock leads to significant alterations of several hormones, e.g. ACTH, corticosterone and -endorphin, it is not known whether plasma melatonin levels are affected under this condition and if so, whether the effects are comparable in males and females. Using a radioimmunoassay, it was found that plasma melatonin levels were significantly increased in male and proestrus female C3H/HeN mice immediately after hemorrhagic shock. However, in male mice, by two hours after hemorrhage and resuscitation, plasma melatonin returned to levels comparable to those seen in control and sham-operated animals. Proestrus female mice, on the other hand, showed significantly increased plasma melatonin levels at two hours after surgery when compared to unoperated control animals. Although the significance and biological role of the transient increased plasma melatonin levels after hemorrhagic shock remain to be determined, it appears that the pineal gland and/or an extrapineal source of melatonin, of both male and proestrus female mice responds to severe hypotension by increased release of melatonin.     

Ultrastructural changes in uterine myometrium of mice with experimentally-induced adenomyosis

Ectopic pituitary transplantation induced a high incidence of adenomyosis in SHN mice. Early signs of the development of adenomyosis were the penetration of stromal connective tissue into myometrium followed by uterine gland invasion. Associated with these changes, the inner layer of myometrium showed the involution of smooth muscle cells and distended intercellular spaces.     

Changes in the sialic acid content of chick thymus and bursa of Fabricius during age-involution.

The sialic acid content of both thymus and bursa of Fabricius during their growth and involution phases in chick has been reported in this study. It is observed that the sialic acid concentration is very high in 1-week-old chickens. The concentration subsequently decreases to a significant level and rises again prior to the onset of involution. In the post-involution period, a more or less minimal and constant level is maintained. The role of sialic acid in cellular activities of thymo-bursal system has been discussed.     

Effects of Freund's complete adjuvant on the dirunal rhythms of neuroendocrine processes and ornithine decarboxylase activity in various tissues of male rats

The aim of this study was to investigate the effects of Freund's complete adjuvant (FCA) on the diurnal rhythms of hormonal parameters in serum and ornithine decarboxylase (ODC) activity in various tissues of male rats. On days 1–2 after FCA, increase of ODC activity (used to evaluate the level of activation) was observed in the hypothalamus, pituitary gland, adrenal medulla, adrenal cortex, liver and lymphoid tissues, while the ODC activity in the kidney was reduced. This was accompanied by an increase in serum corticosterone. On days 3–4 after FCA, ODC activity remained elevated in the pituitary gland, liver and lymphoid tissues, while the ODC activity in the testes and panceas was reduced; kidney ODC activity returned to baseline. This was associated with increased serum levels of prolactin (Prl) and luteinizing hormone, but decreased growth hormone, testosterone and insulin. The increase in ODC activity in the thymus, as well as the reduced ODC activity in the testes and kidney, can be obtained with paraffin. Furthermore, bromocryptine microcapsules (CBLA) reduced the FCA-induced increase of ODC activity in the pituitary gland, liver and lymphoid tissues (days 3–4) but did not affect the changes in other tissues. The increase in ODC activity in the pituitary gland, liver and lymphoid tissues is specific for FCA. A role for Prl in the induction of ODC in liver and lymphoid tissues is suggested by the fact that CBLA suppresses this enhancement.     

Ultrastructural changes in uterine myometrium of mice with experimentally-induced adenomyosis

Summary Ectopic pituitary transplantation induced a high incidence of adenomyosis in SHN mice. Early signs of the development of adenomyosis were the penetration of stromal connective tissue into myometrium followed by uterine gland invasion. Associated with these changes, the inner layer of myometrium showed the involution of smooth muscle cells and distended intercellular spacesThis work was supported in part by Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan     

Influence of the pineal gland on the reproductive system of the male house mouse

Summary Procedures designed to express pineal-mediated antigonadotropic activity were performed upon male house mice. Neither blinding nor blinding plus olfactory bulbectomy of house mice resulted in testicular involution within 12 weeks. The pineal gland appears to be of little significance to reproduction in the house mouse.Supported by NICHHD grant No. HDO 7119-092.Supported by NICHHD grant No. 5P5 OHDO 8338.Supported by NSF grant No. SPI 7922 372.     

延衰合剂对D-半乳糖诱导的亚急性衰老小鼠免疫功能影响的实验研究

目的 研究延衰合剂( yanshuai mixture,YSM)对D-半乳糖所致亚急性衰老小鼠胸腺、脾脏组织结构及白介素2水平的影响.方法 选昆明系小鼠,用D-半乳糖建立衰老模型.应用光镜、电镜技术观察延衰合剂治疗前后衰老小鼠胸腺、脾脏的形态学改变;检测胸腺指数及脾脏指数;酶联免疫分析法检测血清白介素2的变化.结果 衰...     

Zur zellulären Reaktion des Thymus nach Tumorimplantation

Summary As is shown by electron-microscopic examinations of the thymus, the implantation of ascites-tumour cells usually causes degenerative changes of thymus cells in mice with simultaneous involution of the organ. These changes are already perceptible on the second day. After 7 days most of the lymphocytes give evidence of a so-called segregation of karyoplasm, whereas simultaneously a high dissociation of cells is partially observed. Pyknotic cells could not be observed. Obviously, however, the cellular reaction of the separate thymi is different, which is possibly in relation with tumour growth.     

Inhibition by SMS 201-995 of normal mammary gland growth in mice

Twice daily s.c. injection of 5 ng or 50 ng of SMS 201-995 between 25 and 55 days of age induced a significant retardation of normal mammary gland growth in C3H/He virgin mice, associated with the reduced plasma GH level. Meanwhile, plasma prolactin level and the pattern of estrous cycle were affected little by SMS treatments. The results indicate an involvement of GH in normal mammary gland growth in mice.     

Inhibition by SMS 201-995 of normal mammary gland growth in mice

Summary Twice daily s.c. injection of 5 ng or 50 ng of SMS 201-995 between 25 and 55 days of age induced a significant retardation of normal mammary gland growth in C3H/He virgin mice, associated with the reduced plasma GH level. Meanwhile, plasma prolactin level and the pattern of estrous cycle were affected little by SMS treatments. The results indicate an involvement of GH in normal mammary gland growth in mice.     

Changes in the sialic acid content of chick thymus and bursa of Fabricius during age-involution

Summary The sialic acid content of both thymus and bursa of Fabricius during their growth and involution phases in chick has been reported in this study. It is observed that the sialic acid concentration is very high in 1-week-old chickens. The concentration subsequently decreases to a significant level and rises again prior to the onset of involution. In the postinvolution period, a more or less minimal and constant level is maintained. The role of sialic acid in cellular activities of thymo-bursal system has been discussed.Supported by the University Grants Commission, Govt of India under the scheme Support to Research.     

Apoptotic cell death in the lactating mammary gland is enhanced by a folding variant of α-lactalbumin

Apoptosis is essential to eliminate secretory epithelial cells during the involution of the mammary gland. The environmental regulation of this process is however, poorly understood. This study tested the effect of HAMLET (human -lactalbumin made lethal to tumor cells) on mammary cells. Plastic pellets containing HAMLET were implanted into the fourth inguinal mammary gland of lactating mice for 3 days. Exposure of mammary tissue to HAMLET resulted in morphological changes typical for apoptosis and in a stimulation of caspase-3 activity in alveolar epithelial cells near the HAMLET pellets but not more distant to the pellet or in contralateral glands. The effect was specific for HAMLET and no effects were observed when mammary glands were exposed to native a-lactalbumin or fatty acid alone. HAMLET also induced cell death in vitro in a mouse mammary epithelial cell line. The results suggest that HAMLET can mediate apoptotic cell death in mammary gland tissue.Received 30 January 2004; received after revision 5 March 2004; accepted 16 March 2004     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse.

Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse

Summary Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

Neuropeptide Y inhibits corticosterone secretion by isolated rat adrenocortical cells

Summary Studies with isolated rat adrenocortical cells have shown that neuropeptide Y (NPY) inhibits both basal and ACTH-stimulated corticosterone secretion. These results suggest the regulatory role of NPY in corticosterone secretion from the adrenal gland, especially during stress.Supported in part by a grant CPBP 06.03.3.16.     

Eosinophilic granulocyte deficiency in mice mutant in sl and w loci

Homozygous Sl/Sl and Wv/Wv mice were found to have approximately 15% of the normal number of circulating eosinophils. Furthermore, these mice exhibited reduced numbers of eosinophilic granulocytes in the bone marrow, spleen and thymus as compared to littermate control normal mice.     

Neuropeptide Y inhibits corticosterone secretion by isolated rat adrenocortical cells

Studies with isolated rat adrenocortical cells have shown that neuropeptide Y (NPY) inhibits both basal and ACTH-stimulated corticosterone secretion. These results suggest the regulatory role of NPY in corticosterone secretion from the adrenal gland, especially during stress.