@article{FeuersteinSirenGoldsteinetal.1989,
  author    = {Feuerstein, G. and Sir{\´e}n, Anna-Leena and Goldstein, DS and Johnson, AK and Zerbe, RL},
  title     = {The effect of morphine on the hemodynamic and neuroendocrine responses to hemorrhagic shock in conscious rats},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49033},
  year      = {1989},
  abstract  = {We have previously reported that analgesic doses of morphine accelerate mortality of rats exposed to hemorrhage (Feuerstein and Siren: Circ Shock 19:293-300, 1986). To study the potential mechanisms involved in this phenomenon, rats were chronically implanted with catheters in the femoral vessels and morphine (1.5 or 5 mg/kg) was administered 30 min or 24 hr after bleeding (8.5 mll300 g over 5 min) while arterial blood pressure and heart rate were continuously monitored. Furthermore, the effect of morphine (5 mg/kg) on cardiac output (CO) response to hemorrhage was studied in rats chronically equipped with a mini thermistor for CO monitoring by a thermodilution technique. In addition, plasma catecholamines (HPLC), plasma renin activity (PRA, RIA), vasopressin (RIA), pH, and blood gases were also determined. Morphine administration 30 min after hemorrhage produced a pressor response and tachycardia which were in marked contrast to its depressor effect in intact rats. Morphine elevated PRA and epinephrine but not vasopressin, while blood pH and gases showed no consistent change as compared to salinetreated hemorrhaged rats. Morphine given after the bleeding resulted in enhanced cardiac depression in response to a second bleed of 2 m1l300 g. Our data suggest that activation of pressor mechanisms by morphine during hypovolemic hypotension might enhance vasoconstriction in essential organs, depress cardiac function, and further reduce effective tissue perfusion.},
  subject      = {Medizin},
  language  = {en}
}
@article{FeuersteinSiren1987,
  author    = {Feuerstein, Giora and Sir{\´e}n, Anna-Leena},
  title     = {The Opioid System in cardiac and vascular regulation of normal and hypertensive states},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47418},
  year      = {1987},
  abstract  = {The endogenous opioid system includes three major families of peptides: 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. Opioid peptides and opioid receptors, of which multiple forms have been defined, are present in the central nervous system and peripheral neural elements. In the central nervous system, opioid peptides and receptors are found in forebrain and hindbrain nuclei involved in baroregulation, sympathoadrenal activation, and several other vital autonomic functions. In the periphery, opioid peptides are found in autonomic ganglia, adrenal gland, heart, and other organs; multiple opioid receptors are also found in vascular tissue, heart, and kidneys. Although little is known to date on the regulatory mechanisms of the opioid system in normal cardiovascular states, it became clear that cardiovascular stress situations substantially modify the activity of the endogenous opioid system. The purpose of this review is to clarify the sites of interaction of the opioid system with all major components of the cardiovascular system and indicate the potential role of this system in the ontogenesis of cardiac malfunction, vascular diseases, and hypertension.},
  subject      = {Medizin},
  language  = {en}
}
@article{FeuersteinSiren1987,
  author    = {Feuerstein, G. and Sir{\´e}n, Anna-Leena},
  title     = {Cardiovascular effects of enkephalins},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49048},
  year      = {1987},
  abstract  = {Enkephalins and their receptors are found in neurons and nerve terminals known to be involved in central cardiovascular control as well as the peripheral sympathetic and parasympathetic systems. Enkephalins and opioid receptors were also iden tified in the heart, kidneys, and blood vessels. The enkephalins interact with several specific receptors, of which p, 0, and K have been best characterized. Enkephalins administered to humans or animals produce cardiovascular effects which depend on the spedes, route of administration, anesthesia, and the selectivity for receptor subtype. While little information exists on the role of enkephalins in normal cardiovascular control, current data suggest that enkephalins might have a role in cardiovascular stress responses such os in shock and trauma.},
  subject      = {Medizin},
  language  = {en}
}
@article{SirenFeuerstein1987,
  author    = {Sir{\´e}n, Anna-Leena and Feuerstein, Giera},
  title     = {Central autonomic pharmacology of thyrotropin releasing hormone},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49051},
  year      = {1987},
  abstract  = {Thyrotropin releasing hormone (TRH, I-pyroglutamyl-l-histidyl-l-prolinamide) was the fIrst hypothalamic releasing SUbstance to be isolated, chemically characterized and synthetized /1/. The studies to date have revealed that the thyrotropin release from the pituitary gland is only one of the numerous actions of TRH. In addition to its endocrine actions (TSH and prolactin release) this tripeptide has central nervous system actions totally unrelated to its effects on the hypothalamo-pituitary axis. This review aims to summarize the studies on the central nervous system' actions of TRH with special emphasis on the autonomic pharmacology of this peptide.},
  subject      = {Medizin},
  language  = {en}
}
@article{FeuersteinSiren1986,
  author    = {Feuerstein, G. and Sir{\´e}n, Anna-Leena},
  title     = {Effect of naloxone and morphine on survival of conscious rats after hemorrhage},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48669},
  year      = {1986},
  abstract  = {The endogenous opioid system has been reported to depress the cardiovascular system during shock states, since naloxone, a potent opiate antagonist, enhances recovery of hemodynamic variables in various shock states. However, the effect of naloxone on long-term survival of experimental animals exposed to hypovolemic hypotension is not clear. The present studies tested the capacity of various doses of naloxone to protect conscious rats from mortality following various bleeding paradigms. In addition, the effect of morphine on survival of rats exposed to hemorrhage was also examined. In the six different experimental protocols tested, naloxone treatments failed to improve short- or long-term survival; in fact, naloxone treatment reduced short-term survival in two of the experimental protocols. Morphine injection, however, enhanced the mortality of rats exposed to hemorrhage in a dose-dependent manner. It is concluded that while opiates administered exogenously decrease survival after acute bleeding, naloxone has no protective action in such states and, like morphine, it may decrease survival in some situations.},
  subject      = {Medizin},
  language  = {en}
}
@article{SirenSvarstroemFraserPaakkari1985,
  author    = {Sir{\´e}n, Anna-Leena and Svarstr{\"o}m-Fraser, M. and Paakkari, I.},
  title     = {Central cardiovascular effects of the endoperoxide analogue U-46619 i.c.v. in rats},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49064},
  year      = {1985},
  abstract  = {Thromboxanes are abundantly present in the rat brain but their possible physiological functions in the brain are not known. The prostaglandin endoperoxide analogue U-46619 is a selective agonist of TxA2 receptors in many peripheral tissues. In the present study the ·central cardiovascular and ventilatory effects of U-46619 were investigated in rats. In conscious spontaneously hypertensive rats (SHR) U-46619 (1-100 nmol/kg i.c.v.) induced a strong dose-related increase in blood pressure but had no significant effect on heart rate. In conscious normotensive rats (NR) neither blood pressure nor heart rate was significantly affected. Furthermore, U-46619 (0.1-100 nmol/kg i.c.v.) had no significant effect on blood pressure, heart rate or ventilation in urethane-anaesthetised NR . The results demonstrate an increased sensitivity of SHR to TxA2.},
  subject      = {Medizin},
  language  = {en}
}
@article{SirenPaakkari1984,
  author    = {Sir{\´e}n, Anna-Leena and Paakkari, I.},
  title     = {Cardiovascular effects of TRH i.c.v. in conscious rats},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49071},
  year      = {1984},
  abstract  = {In addition to the endocrine effects, the thyrotropin releasing hormone (TRH) is known to induce dose-dependent increases in blood pressure and heart rate after intracerebroventricular (i.c.v.) administration in urethane-anaesthetised rats (1, 2). The a~ of the present study was to investigate whether TRH has similar effects in conscious rats of various strains i.e. spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto (WKY) and Wistar (NR) rats.},
  subject      = {Medizin},
  language  = {en}
}
@article{Siren1982,
  author    = {Sir{\´e}n, Anna-Leena},
  title     = {Central cardiovascular and thermal effects of prostaglandin D2 in rats},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48658},
  year      = {1982},
  abstract  = {Prostaglandin D2 (PGD2) is the most common prostaglandin type of tile rat brain. Recently a neurornodulator role for PGD2 has been suggested. In the present work the central cardiovascular and thermal effects of PGDz were studied in urethane-anaesthetised rats. Mlen adrndnistered at the doses of 0.001-10 ~g/rat into the lateral cerebral ventricle(i.c.v.), PGD2 slightly increased the blood pressure, heart rate and body ternpera~ ure. The highest dose caused also an initial hypotensive effect. Upon lntravenous injections PGD2 (0.1-10 ~g/rat) initially decreased and then weakly increased the blood pressure but had only negligible effects on heart rate and body temperature. Central pretreatment with sodium meclofenamate or indomethacin (1 mg/rat i.c.v.) antagonised effectively all the recorded central effects of PGD2. The central cardiovascular and thermal effects of PGD2 were much weaker than those obtained earlier with other prostaglandins, such as PGF2alpha and PGE2.. Therefore, in spite of its abundance in the brain PGD2 may not be very important for the central cardiovascular and thermal regulation in the rat.},
  subject      = {Medizin},
  language  = {en}
}