Author/Editor		Žak, Agata; Irman-Florjanc, Tatjana; Biedka, Izabela; Žwirska-Korczala, Krystyna; Jochem, Jerzy
Title		Renal microcirculatory blood flow changes in metoprine-induced reversal of haemorrhagic hypotension in rats
Type		članek
Source		Acta Medica Martiniana
Vol. and No.		Letnik 8, št. 1
Publication year		2008
Volume		str. 3-7
Language		eng
Abstract		Background and aim: The histaminergic system is involved in the central cardiovascular regulation. An increase in central histamine concentration after inhibition of histamine N-methyltransferase (HNMT) activity leads to a long-lasting pressor effect, with an increase in survival rate, in haemorrhage-shocked rats. The study was undertaken to examine renal cortical microcirculatory changes associated with HMNT antagonist metoprine-induced resuscitating effect in rats. Methods: Study was performed in ketamine/xylazine-anaesthetised male Wistar-Kyoto rats subjected to irreversible haemorrhagic shock with mean arterial pressure (MAP) 20-25 mmHg. Animals were treated with metoprine (15 mg/kg; intraperitoneally [ip]) or saline (0.5 ml; ip). Haemodynamic (MAP, heart rate [HR], renal microcirculatory blood flow [RMBF]) and biochemical (renal cortical histamine concentration) parameters were measured. Results: Metoprine given peripherally evoked a long-lasting pressor effect with an increase in HR and RMBF. Renal cortical microcirculatory changes were associated with a lower local histamine concentration. Conclusion: Inhibition of HNMT activity with metoprine administered intraperitoneally in anaesthetised haemorrhage-shocked rats produces a resuscitating effect with an increase in renal microcirculatory blood flow. The effect can be associated not only with central histamine-induced activation of compensatory mechanisms, but also with peripheral histamine-mediated vasodilatation.
Descriptors		SHOCK, HEMORRHAGIC HISTAMINE METHYLTRANSFERASES HYPOTENSION KIDNEY MICROCIRCULATION HEART RATE RATS, WISTAR