TY  - JOUR
A1  - Vonhof, S.
A1  - Sirén, Anna-Leena
A1  - Feuerstein, Giora
T1  - Volume-dependent spatial distribution of microinjected thyrotropin-releasing hormone (TRH) into the medial preoptic nucleus of the rat
N2  - The present study was performed to qua ntify the distribution of a peptide neurotransmitter after microinjection into the medial preoptic area (POM), using a technique suitable for conscious animal preparations. The results indicate that only 50-ni volumes of injected tracer were sufficiently localized with 77 ± 9% recovery in the POM. Injections of higher volumes resulted in an increasing spread of tracer into distant anatomical regions and structures, including the needle tract and cerebral ventricles. The amount of tracer localized in the POM decreased to 38±4% (200 nl) (P < 0.05) and 41 ±8% (500 nl) (P <0.05), respectively. The data suggest that the volume of injection is critical for intraparenchymal injections into structures of a diameter of I mm or less, such as the POM and should not exceed 50 nl in conscious animal preparations.
KW  - Neurophysiologie
KW  - Neurobiologie
KW  - Autoradiography
KW  - Microinjection
KW  - Hypothalamus
KW  - TRH
KW  - Neuropeptides
KW  - [3H][3Me-His2]-TRH
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47421
ER  - 
TY  - JOUR
A1  - Feuerstein, G.
A1  - Zerbe, R. L.
A1  - Sirén, Anna-Leena
T1  - Supraoptic nuclei in vasopressin and hemodynamic responses to hemorrhage in rats
N2  - CARDIOVASCULAR and vasopressin (A VP) responses to hcmorrhagc wcrc studicd in rats with lesions of the hypothalamic supraoptic nuclei (SONL). Bleeding caused hypotension and increase in heart rate (HR) and A VP. SONL rats failed to fully recover from bleeding as compared to normal rats. Plasma A VP in SONL rats was in the normal in basal conditions, but failed to increase to levels attained in normal rats throughout the post-hemorrhage period. These data suggcst that the supraoptic nuclei are the primary regulatory sitcs for A VP release in rcsponse to hemorrhage and that lack of adequate A VP release significantly retards blood pressure recovery after bleeding.
KW  - Neurobiologie
KW  - Hypothalamus
KW  - Supraoptic nucleus
KW  - Hemorrhage
KW  - Vasopressin
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63057
ER  - 
TY  - JOUR
A1  - Feuerstein, G.
A1  - Sirén, Anna-Leena
T1  - Hypothalamic µ-receptors in the cardiovascular control: a review
N2  - The endogenous opioid system includes three major families of peptides [22): dynorphins (derived from pre-proenkephalin B); endorphins (derived from pre-proopiomelanocortin) and enkephalins (derived from pre-proenkephalin A). Multiple species of opioid peptides are derived from these major precursors and many of them possess potent cardiovascular properties. Multiple forms of opioid receptors have been defined in the central nervous system. Although the relationship of these receptors to the multiple actions of the opioid systems is not weil understood, some predications can be made: in vitro the dynorphin-related peptidesbind preferentially to kappa-opioid receptors; the enkephalins bind preferentially to delta and JL-opioid receptors and while beta-endorphin binds to mu- and delta-, but not to kappa-opioid receptors. While littleis known on the roJe ofthe opioid system in normal cardiovascular regulation, it has become clear that cardiovascular stress situations substantially modify the activity ofthe endogenous opioid system. This review focuses on the mu-opioid system in the hypothalamus with special emphasis on its potential roJe in cardiovascular control of both normal and pathophysiologic states.
KW  - Neurobiologie
KW  - µ opioid receptors
KW  - Hypothalamus
KW  - Cardiovascular system
KW  - Sympathetic nervous system
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63228
ER  -