Summary:
Long-lasting problem on the differentiation of adenohypophyseal cell, which prepares them for their specific tasks
(somatotropic, lactotropic ect.), becomes elucidated after recognition of the differentiational effect of transcription
factor Pit-1. Expression of that factor in somatotrops results in STH secretion, contrary to lactotrops producing
prolactin. Subclinical hypothyreosis (increased TSH with normal T3 and T4) endangers vessel not because of
hypercholesterolemia, but because of changes in the dynamics of the blood flow. The idea of cardiotropic effect of
thyroidal hormones is supported by the finding that administration of trijodthyronine to children after the surgical
correction of heart malformations (cardiopulmonary bypass) improves myocardial function - it elevates cardiac
output and decreases requirements on the intensive care. Receptors for hormones in tissues are flexible, they can be
„heterooligomers” for dopamine and somatostatin. Mutations of mineralocorticoid receptor may cause hypertension
in pregnancy and progesterone receptors have several isoforms. Receptors can be also activated by short exposition
to a hormone. Glucocorticoids have probably also membrane receptors. Diabetes mellitus „type I” needn’t to be
immunogenic and DM type II not only results from down-regulation of receptors and subsequent insulin resistance, but
it can be also caused by defects in insulin secretion. Insulin has receptors in the brain and participates in the appetite
regulation. The attempt to use „desensibilisation” by peroraly administered insulin in patients with immunogenic DM
had no effect. Stress affects memory mechanisms, heavy emotional stress during gravidity can bring congenital
malformations. The decrease of mental functions in aged women depends on the level of free estradiol (the fraction,
which is not bound to plasma proteins). Activation of dopaminergic neurons can be achieved by neurotropic growth
factors. Nesiritide is a recombinant brain natriuretic hormone successfully tested in heart failure. The role of leptin in
the appetite regulation in man is still not clear, other signalling molecules may have also an effect, e.g., ghrelin, which
primarily stimulates STH secretion and brings about weight gain. Sildenafil influences nitrergic neurons elsewhere than
in penis, for example it has positive effects in patients with oesophageal achalasia.
Key words:
adenohypophysa, transcription factor Pit-1, thyroxine effects, receptor flexibility, diabetes mellitus,
mental functins, nesiritide, leptin, nitrergic regulations.
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