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Biomedical subjects

I Hăulică

Publications and source records attributed to I Hăulică.

At least 19 recordsLinked to original sources

Possible hormonal role of the angiotensin-like peptides in mammals' pineal gland.

An isorenin is synthetized in the pineal gland cells. The amount of isorenin as well as the synthesis of angiotensin I and II in the pineal gland depends on the circadian rhythm, osmotic stimuli and stimulation of the cervical sympathetic postganglionar fibres. Pineal angiotensin is released both into the blood and in the cerebrospinal fluid (CFS). The major site of the pineal angiotensin action are the circumventricular organs, the preiventricular receptors of the anterior hypothalamus and the epiphysis cerebri itself. Except its participation in regulating arterial pressure and the hydroelectrolytic metabolism, through its central effects on the brain, pineal angiotensin-like peptides also participate in the pool of circulating angiotensin and it may represent Farrell's pineal glomerulotropic factor.

Angiotensin I↗

A renin-like activity in pineal gland and hypophysis.

Using Boucher micromethod for determining renin activity in the rat pineal gland and hypophysis tissues, before and after NaCl 10% i.v. administration, the normal rats showed an average value of 96.8 +/- 21 ng Ang/g/h at the hypophysis level, and 325 +/- 66 ng Ang/g/h in epiphysis. In rats previously treated with 1--1.5 ml. NaCl 10% i.v., a more reduced renin-like activity was found both in hypophysis and epiphysis, that is 36.5 +/- 13 ng Ang/g/h and 144.5 +/- 38 Ang/g/h, respectively. In keeping with the previous data regarding the drinking and ADH-releasing effects of angiotensin, the obtained results plead for a possible participation of the cerebral glandular tissue renin in the self-regulating of the hydroelectrolytic balance.

Animals↗

[Experimental data on epithelial factors modulating bronchial reactivity].

A tracheobronchial smooth muscle reactivity study on isolated guinea pig tracheal rings was done. The presence of two different factors active on smooth muscle, an inhibiting one, as well as an activating one was identified. Generated on different pathways, the epithelial derived relaxing factor is a cyclooxygenase dependent prostaglandin, while the activating epithelial factor seems to be a thromboxane derivate.

Animals↗

Actual data concerning the brain--immune system interface.

After a brief presentation of the immune system as sensorial and effector organ, which recognizes and defends against cellular aggressions, the main psycho-neuro-endocrine components of immune reaction regulation and modulation will be shown. Both central nervous structures that control the hormonal emissions, the vegetative innervation of the lymphoid organs as well as the afferent neurohumoral pathways involved in the making of the self-regulating and neuromodulating circuits of the humoral and cellular immune responses will be mentioned. An important position will be held by the interrelations between the hypothalamus-pituitary-corticoadrenal gland, the sympathetic-parasympathetic efferent pathways and the chemical messengers (hormones, neurotransmitters, interleukins, neurotrophins) which make possible the bi-directional neuroimmune communication for maintaining the homeostatic balances on this third effector pathway, too. Also will be presented experimental proof concerning the ability of central neurons to secrete neuromodulator cytokines and the presence of specific receptors for the various neuroactive molecules within lymphoid organs and circulating lymphocytes. To close, the psychoemotional components of the neuro-immunomodulator circuits will be mentioned, using as examples the changes induced by stress generally and oxidative stress in particular.

Animals↗