TY  - JOUR
A1  - Vonhof, S.
A1  - Sirén, Anna-Leena
A1  - Feuerstein, G.
T1  - Central ventilatory effects of thyrotropin-releasing hormone in the conscious rat
N2  - Thyrotropin-releasing hormonewas shown to exert potent ventilatory effects after centrat administration. These data, however, were derived from studies using anesthetized animal preparations. Since TRH elicits strong arousal reactions, the observed ventilatory effects of TRH under anesthesia may have been due to nonspecific reduction in the anesthetic state of the animals. In order to clarify the extent to which the reversal of anesthesia may change ventilatory parameters after TRH application, we investigated the effect of TRH on Ventilation rate, relative tidal volume, relative respiratory minute volume, CO\(_2\) production CO\(_2\) consumption, and locomotor activity in the conscious, unrestrained rat. Intracerebroventricular application of TRH induced a dose-dependent, sustained increase in ventilation rate, relative tidal volume, and relative respiratory minute volume of maximally 128%, 890%, and 235%, respectively. In addition, CO\(_2\) production and O\(_2\) consumption were elevated by 4.6 and 11.7 fold, whiJe no significant changes in locomotor activity were observed. The results suggest that TRH stimulates ventilation by a mechanism independent of its analeptic properties.
KW  - Neurobiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63075
ER  - 
TY  - JOUR
A1  - Sirén, Anna-Leena
A1  - Vonhof, S.
A1  - Feuerstein, G.
T1  - Hemodynamic defense response to thyrotropin-releasing
hormone injected into medial preoptic nucleus in rats
N2  - No abstract available
KW  - Neurobiologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63099
ER  - 
TY  - JOUR
A1  - Paakkari, P.
A1  - Paakkari, I.
A1  - Vonhof, S.
A1  - Feuerstein, G.
A1  - Sirén, Anna-Leena
T1  - Dermorphin analog Tyr-D-Arg\(^2\)-Phe-sarcosine-induces opioid analgesia and respiratory stimulation - the role of Mu\(_1\)-  receptors?
N2  - Tyr-o-Arg\(^2\)-Phe-sarcosine\(^4\) (TAPS), a mu-selective tetrapeptide analog of dermorphin, induced sustained antinociception and stimulated ventilatory minute volume (MV) at the doses of 3 to 100 pmol i.c.v. The doses of 30 and 100 pmol i.c.v. induced catalepsy. The effect of TAPS on MV was in negative correlation with the dose and the maximal response was achieved by the lowest (3 pmol) dose (+63 ± 23%, P < .05). Morphine, an agonist at both mu\(_1\) and mu\(_2\) sites, at a dose of 150 nmol i.c.v. (equianalgetic to 100 pmol of TAPS decreased the MV by 30%, due to a decrease in ventilatory tidal volume. The antinociceptive effect of TAPS was antagonized by naloxone and the mu, receptor antagonist, naloxonazine. Naloxonazine also attenuated the catalepsy produced by 1 00 pmol of TAPS i.c. v. and the respiratory Stimulation produced by 3 pmol of TAPS i.c.v. Pretreatment with 30 pmol of TAPS antagonized the respiratory depression induced by the mu opioid agonist dermorphin (changes in MV after dermorphin alone at 1 or 3 nmol were -22 ± 1 0% and -60 ± 9% and, after pretreatment with TAPS, +44 ± 11 % and -18 ± 5%, respectively). After combined pretreatment with naloxonazine and TAPS, 1 nmol of dermorphin had no significant effect on ventilation. In contrast, pretreatment with a low respiratory stimulant dose (10 pmol i.c.v.) of dermorphin did not modify the effect of 1 nmol of dermorphin. ln conclusion, the antinociceptive, cataleptic and respiratory stimulant effects of TAPS appear to be a related to its agonist action at the mu, opioid receptors. TAPS did not induce respiratory depression (a mu\(_2\) opioid effect) but antagonized the respiratory depressant effect of another mu agonist. Thus, in vivo TAPS appears to act as a mu\(_2\) receptor antagonist.
KW  - Neurobiologie
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62984
ER  -