Cardiovascular effects of microinjection of corticoids and antagonists into the rostral ventrolateral medulla in rats. 1995

D N Zhu, and L M Xue, and P Li
Department of Physiology, Shanghai Medical University, China.

Experiments were performed on Wistar or Sprague-Dawley rats of both sexes. Microinjection of corticosterone (10 or 40 ng/0.1 microliter/site) into the rostral ventrolateral medulla (rVLM) caused an increase in systolic blood pressure (SBP), heart rate (HR) and pressor response induced by stimulation of the dorsal periaqueductal grey (dPAG) in the midbrain. Microinjection of aldosterone (10 or 40 ng/0.1 microliter/site) into the rVLM had similar effects showing a higher level and longer period than that of corticosterone. All these effects were dose-dependent. Microinjection of glucocorticoid antagonist RU 38486 (40 ng/0.1 microliter/site) or mineralocorticoid antagonist spironolactone (40 ng/0.1 microliter/site) caused a decrease in SBP, HR and the pressor response induced by stimulation of the dPAG. The inhibitory effects of spironolactone were more apparent. These results suggest that both corticoids could exert central modulatory effects on the resting cardiovascular activities and facilitate the pressor response during a defense reaction, and the rVLM is an essential area for the location of the central modulation. These effects may play an important role in the incidence and development of hypertension induced by stress.

UI MeSH Term Description Entries
D008297 Male Males
D008526 Medulla Oblongata The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities. Accessory Cuneate Nucleus,Ambiguous Nucleus,Arcuate Nucleus of the Medulla,Arcuate Nucleus-1,External Cuneate Nucleus,Lateral Cuneate Nucleus,Nucleus Ambiguus,Ambiguus, Nucleus,Arcuate Nucleus 1,Arcuate Nucleus-1s,Cuneate Nucleus, Accessory,Cuneate Nucleus, External,Cuneate Nucleus, Lateral,Medulla Oblongatas,Nucleus, Accessory Cuneate,Nucleus, Ambiguous,Nucleus, External Cuneate,Nucleus, Lateral Cuneate
D008845 Microinjections The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes. Microinjection
D008901 Mineralocorticoids A group of CORTICOSTEROIDS primarily associated with water and electrolyte balance. This is accomplished through the effect on ION TRANSPORT in renal tubules, resulting in retention of sodium and loss of potassium. Mineralocorticoid secretion is itself regulated by PLASMA VOLUME, serum potassium, and ANGIOTENSIN II. Mineralocorticoid,Mineralocorticoid Effect,Mineralocorticoid Effects,Effect, Mineralocorticoid,Effects, Mineralocorticoid
D010487 Periaqueductal Gray Central gray matter surrounding the CEREBRAL AQUEDUCT in the MESENCEPHALON. Physiologically it is probably involved in RAGE reactions, the LORDOSIS REFLEX; FEEDING responses, bladder tonus, and pain. Mesencephalic Central Gray,Midbrain Central Gray,Central Gray Substance of Midbrain,Central Periaqueductal Gray,Griseum Centrale,Griseum Centrale Mesencephali,Periaqueductal Gray Matter,Substantia Grisea Centralis,Substantia Grisea Centralis Mesencephali,Central Gray, Mesencephalic,Central Gray, Midbrain,Gray Matter, Periaqueductal,Gray, Central Periaqueductal,Griseum Centrale Mesencephalus,Periaqueductal Grays, Central
D001794 Blood Pressure PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS. Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
D002319 Cardiovascular System The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body. Circulatory System,Cardiovascular Systems,Circulatory Systems
D003345 Corticosterone An adrenocortical steroid that has modest but significant activities as a mineralocorticoid and a glucocorticoid. (From Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1437)
D005260 Female Females
D005938 Glucocorticoids A group of CORTICOSTEROIDS that affect carbohydrate metabolism (GLUCONEOGENESIS, liver glycogen deposition, elevation of BLOOD SUGAR), inhibit ADRENOCORTICOTROPIC HORMONE secretion, and possess pronounced anti-inflammatory activity. They also play a role in fat and protein metabolism, maintenance of arterial blood pressure, alteration of the connective tissue response to injury, reduction in the number of circulating lymphocytes, and functioning of the central nervous system. Glucocorticoid,Glucocorticoid Effect,Glucorticoid Effects,Effect, Glucocorticoid,Effects, Glucorticoid

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