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The vasopressin content in the neurohypophysis under conditions of intracerebroventricular beta-adrenergic blockade in euhydrated and dehydrated rats

100%

Janus J., Guzek J. W.

Acta Physiologica Polonica

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1987

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tom 38

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nr 5

2

Centrally administered galanin modifies vasopressin and oxytocin release from the hypothalamo-neurohypophysial system of euhydrated and dehydrated rats

100%

Ciosek J., Cisowska A.

Journal of Physiology and Pharmacology

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2003

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tom 54

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nr 4

Galanin (Gal) as a neuropeptide with widespread distribution in the central nervous system may be involved in the mechanisms of vasopressin (AVP) and oxytocin (OT) release from the hypothalamo-neurohypophysial system. Vasopressin and oxytocin content in the hypothalamus and neurohypophysis as well as plasma level of both neurohormones were studied after galanin treatment in euhydrated and dehydrated rats. In not dehydrated rats intracerebroventricular (i.c.v.) injections of Gal did not affect the hypothalamic and neurohypophysial OT content, however, distinctly increased plasma OT concentration. In the same animals Gal diminished the hypothalamic AVP content but was without the effect on neurohypophysial AVP storage; plasma AVP level then raised. Galanin, administered i.c.v. to rats deprived of water, distinctly inhibited AVP and OT release from the hypothalamo-neurohypophysial system. Simultaneously, plasma AVP and OT level was significantly diminished after Gal treatment in dehydrated rats. These results suggest that modulatory effect of galanin on vasopressin and oxytocin release depends on the actual state of water metabolism. Gal acts as an inhibitory neuromodulator of AVP and OT secretion under conditions of the dehydration but stimulates this process in the state of equilibrated water metabolism.

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Vasopressin and oxytoxin release as influenced by thyrotropin-releasing hormone in euhydrated and dehydrated rats

80%

Ciosek J.

Journal of Physiology and Pharmacology

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2002

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tom 53

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nr 3

Since the thyrotropin-releasing hormone (TRH) can modulate the processes of vasopressin (AVP) and oxytocin (OT) biosynthesis and release mainly at the hypothalamo-neurohypophysial level, the present experiments were undertaken to estimate whether TRH, administered intravenously in different doses, modifies these mechanisms under conditions of osmotic stimulation, brought about by dehydration. AVP and OT contents in the hypothalamus and neurohypophysis as well as plasma levels of AVP, OT, free thyroxine (FT4) and free triiodothyronine (FT3) were studied after intravenously TRH treatment in euhydrated and dehydrated for two days male rats. Under conditions of equilibrated water metabolism TRH diminished significantly the hypothalamic and neurohypophysial AVP and OT content but was without the effect on plasma oxytocin level; however, TRH in a dose of 100 ng/100 g b.w. raised plasma AVP level. TRH, injected i.v. to dehydrated animals, resulted in a diminution of AVP content in the hypothalamus but did not affect the hypothalamic OT stores. After osmotic stimulation, neurohypophysial AVP and OT release was significantly restricted in TRH-treated rats. Under the same conditions, injections of TRH were followed by a significant decrease of plasma OT level. I.v. injected TRH enhanced somewhat FT3 concentration in blood plasma of euhydrated animals but diminished FT4 plasma level during dehydration. Data from the present study suggest that TRH displays different character of action on vasopressin and oxytocin secretion in relation to the actual state of water metabolism.

Ograniczanie wyników

2 Journal of Physiology and Pharmacology

1 Acta Physiologica Polonica

2 Ciosek J.

1 Cisowska A.

1 Guzek J. W.

1 Janus J.

1 2003

1 2002

1 1987

The vasopressin content in the neurohypophysis under conditions of intracerebroventricular beta-adrenergic blockade in euhydrated and dehydrated rats

Centrally administered galanin modifies vasopressin and oxytocin release from the hypothalamo-neurohypophysial system of euhydrated and dehydrated rats

Vasopressin and oxytoxin release as influenced by thyrotropin-releasing hormone in euhydrated and dehydrated rats