E Barrett-Connor and D von Muhlen
K.-D. Döhler, A. von zur Mühlen and U. Döhler
Pituitary content and concentration of LH, FSH and prolactin were measured by radioimmunoassay (RIA) at 2-day intervals from birth to puberty in female and male rats. During the first 2 to 3 weeks of life all hormones were low in pituitary content and concentration in both sexes. They all increased in females during the third and fourth week, but decreased sharply during the days before vaginal opening. During the first ovulatory cycle pituitary content and concentration of LH and prolactin increased again, FSH, however, remained low. In males, pituitary LH, FSH and prolactin content reached peak levels during puberty. Our results show a distinct sexual dimorphism for pituitary FSH. Pituitary LH and prolactin content and concentration patterns show similar tendencies in both sexes with a delay of several days in males. The dramatic changes in female pituitary hormone concentrations just before the first ovulation were not detected in males before the first occurrence of mature spermatozoa in the tubuli of the testes.
D. Emrich, M. Albani and A. von zur Mühlen
The five times concentrated gamma globulins of the plasma of 28 hyperthyroid patients were tested by the McKenzie bioassay. Evidence for the presence of LATS was obtained in 22 patients. In order to compare the numerical values of LATS obtained at different times they were corrected, using a laboratory standard, which was tested in each assay, and the mean regression coefficient of three dose response curves of the laboratory standard. The corrected LATS values were then compared with the percentage of 131I T3 in the patients' plasma 24 hours after a therapeutic dose of 131I. There was no difference in the 1311 T3 between the LATS-negative and the LATS-positive subjects, but in the LATS-positive subjects there was a significant positive correlation between the percentage of 1311 T3 and the LATS values (correlation coefficient 0.793; P < 0.001). No correlation could be found between LATS and the relative concentrations of the other labelled iodo-aminoacids in the plasma.
R. D. Hesch, M. Huefner, A. von zur Mühlen and D. Emrich
Serum triiodothyronine (T3) concentrations have been measured in 7 patients with euthyroid endocrine exophthalmos and in 8 patients with hyperthyroidism. These results have been assessed in relation to other tests of thyroid function.
The non-suppressibility of euthyroid endocrine exophthalmos is due to elevated endogenous T3 levels and correlated to a negative response of the pituitary gland to TRH.
In hyperthyroid patients who are euthyroid under antithyroid drug therapy, no general correlation of routine laboratory data with T3 levels, suppressibility and TRH response could be found. There is a gap between normal T3 and T4 levels and the restoration of the normal TRH response. A condition is described in which euthyroid patients show thyrotoxic behaviour of the pituitary receptors.
A. von zur Mühlen, R. D. Hesch, J. Köbberling and D. Emrich
A. von zur Mühlen, J. Köbberling, R. D. Hesch and D. Emrich
A. von zur Mühlen, D. Emrich, R. D. Hesch and J. Köbberling
Plasma concentrations of thyroid stimulating hormone (TSH) were measured radioimmunologically in primary hypothyroid patients after administration of organic iodine (Endojodin®), iodoaminoacids, synthetic corticotrophin (ACTH) and cortisone. During intravenous injections of Endojodin® for 5 days there was a slight but significant decrease of plasma TSH. After oral application of 6 different l-iodoaminoacids in high doses over several days we observed in rough relation to their biologic activity a fall in TSH levels in plasma. D-thyroxine, however, was also active under these conditions. During infusions of synthetic ACTH (β1-24, β1-39) and cortisone in two different doses the TSH levels in primary hypothyroid patients decreased in the same way.
Synthetic thyrotrophin releasing factor (TRF) after intravenous application was followed by an abrupt rise in plasma TSH concentration in euthyroid and primary hypothyroid persons. In secondary hypothyroid and hyperthyroid patients no or only slight effects were observed in the TSH levels. The possible employment of TRF in the diagnosis of thyroidal or hypophyseal disorders is discussed.
H. Wiermann, H. A. Durrer, A. von zur Mühlen, C. Ruppert, R. A. Schmidt and D. Reinwein
K.-D. Döhler, K. Gärtner, A. von zur Mühlen and U. Döhler
Groups of adult male rats were decapitated without anaesthesia 30 seconds or 5, 10, 15 and 60 min after disturbance stress (investigators entering the animal room and moving the cages). The serum concentrations of LH, FSH, TSH, prolactin, triiodothyronine (T3) and thyroxine (T4) were measured by radioimmunoassay and corticosterone by a fluorometric method.
With regard to the hormone levels measured in serum obtained within 30 seconds after induction of disturbance stress to resemble most closely the actual unstressed levels of endogenous hormones in circulation, serum corticosterone levels increased within 5 min. indicating that the procedure was stressful to the animals. In addition the serum prolactin and TSH levels were significantly elevated within 5 min, T3 within 60 min. Whereas corticosterone reached peak levels after 15 min. the serum levels of prolactin, TSH and T3 were still rising after 60 min. The FSH levels remained rather stable during the first 10 min. but started to rise during the following 5 min. At 60 min FSH levels were back to normal. Serum LH and T4 showed only minor fluctuations during the experimental period. These results indicate, that not only is the pituitary-adrenal axis stimulated by emotional stress, but also the pituitary-thyroid axis. It also seems, that emotional stress leads to a general activation of pituitary hormone release. Hence, proper care should be taken with regard to animal keeping, handling and the method of blood collection when dealing with rats as experimental animals.