Till sidans topp

Sidansvarig: Webbredaktion
Sidan uppdaterades: 2012-09-11 15:12

Tipsa en vän
Utskriftsversion

Effects of TRH and TRH an… - Göteborgs universitet Till startsida
Webbkarta
Till innehåll Läs mer om hur kakor används på gu.se

Effects of TRH and TRH analogues on the central regulation of breathing in the rat.

Artikel i vetenskaplig tidskrift
Författare Jan A Hedner
Thomas Hedner
Per Wessberg
Dag Lundberg
Jan Jonason
Publicerad i Acta physiologica Scandinavica
Volym 117
Nummer/häfte 3
Sidor 427-37
ISSN 0001-6772
Publiceringsår 1983
Publicerad vid Farmakologiska institutionen
Sidor 427-37
Språk en
Länkar dx.doi.org/10.1111/j.1748-1716.1983...
www.ncbi.nlm.nih.gov/entrez/query.f...
Ämnesord Animals, Blood Pressure, drug effects, Brain, drug effects, Carbon Dioxide, blood, pharmacology, Heart Rate, drug effects, Male, Oxygen, blood, Partial Pressure, Pyrrolidonecarboxylic Acid, analogs & derivatives, Rats, Rats, Inbred Strains, Respiration, drug effects, Thyrotropin-Releasing Hormone, analogs & derivatives, pharmacology
Ämneskategorier Farmakologi

Sammanfattning

Respiratory activity was studied in rats during light halothane anesthesia. Thyrotropin releasing hormone (TRH) and two TRH analogues: the desamidated form (TRH-OH) and gamma-butyrolactone-gamma-carbonyl-L-histidyl-L-prolinamide citrate (DN 1417) were administered intracerebroventricularly. TRH 0.5-5 micrograms induced a marked tachypnoea with a rapid onset and a duration of at least 20 min. DN 1417, a potent analogue of TRH with a very low TSH (thyroid stimulating hormone) releasing activity was more effective in stimulating respiratory frequency, while TRH-OH, regarded to have neither TSH releasing nor extra hypothalamic effects, at equimolar doses was unable to induce any changes in the respiratory pattern. When TRH was given into the fourth ventricle the dose response curve was slightly shifted to the left. In experiments employing the occluded breath technique, P0.1 was increased in the same magnitude as the mean inspiratory flow (VT/T1). The results also indicated an increase in the gain of the inflation reflex loop whereas the central bulbopontine setting for T1 and TTOT were not significantly changed. Local injection of TRH into the nucleus tractus solitarii induced a stimulation of respiratory frequency which was slower in onset compared to the response seen after injection into the lateral or fourth ventricles. Concomitantly to the respiratory changes, i.c.v. TRH injection induced a hypocarbia and an alkalosis. No changes in blood pressure or heart rate were seen. The respiratory stimulant effect of TRH could be potentiated by pretreatment with naloxone, methylatropine or a low dose of GABA. Haloperidol or propranolol did not significantly change the respiratory effects of TRH, while reserpine pretreatment seemed to blunt some of the ventilatory effects of TRH. It seems likely that TRH has few direct effects on brain stem neurones involved in the central regulation of respiration, but the main effects seem to be elicited in areas rostral to the brain stem. The respiratory stimulating effect of TRH is unrelated to TSH. Furthermore, other neurotransmitter systems might also be involved in modulation of the respiratory stimulation evoked by TRH.

Sidansvarig: Webbredaktion|Sidan uppdaterades: 2012-09-11
Dela:

På Göteborgs universitet använder vi kakor (cookies) för att webbplatsen ska fungera på ett bra sätt för dig. Genom att surfa vidare godkänner du att vi använder kakor.  Vad är kakor?