Cardiovascular effects of microinjection of ANF and brain natriuretic peptide into ventrolateral medulla
| Autor: | F. R. Calaresu, M. Bergaglio, G. L. Avanzino, Piero Ruggeri, R. Ermirio |
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| Rok vydání: | 1990 |
| Předmět: |
Male
medicine.medical_specialty Mean arterial pressure Baroreceptor Microinjections Physiology Blood Pressure Nerve Tissue Proteins Cardiovascular System Cardiovascular Physiological Phenomena Atrial natriuretic peptide Heart Rate Physiology (medical) Internal medicine Natriuretic Peptide Brain Medicine Animals Microinjection Medulla Medulla Oblongata business.industry Rats Inbred Strains Rostral ventrolateral medulla Brain natriuretic peptide Rats Endocrinology cardiovascular system Medulla oblongata business hormones hormone substitutes and hormone antagonists Atrial Natriuretic Factor |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0002-9513 |
| Popis: | Cardiovascular effects of microinjection of atrial natriuretic factor (ANF) into 77 sites of the ventrolateral medulla (VLM) were investigated in urethan-anesthetized rats. Changes in mean arterial pressure (MAP) and heart rate (HR) in response to injections of glutamate into these sites were used to determine that they contained cardiovascular neurons. ANF (20 nl of 10(-7) M) decreased MAP [-8.9 +/- 1.5 (SE) mmHg] and HR [-9.0 +/- 2.8 (SE) beats/min] in 5 of 36 vasopressor sites identified by glutamate located in the more rostral and lateral aspect of the rostral VLM (RVLM); no effect was elicited in the other 31 RVLM sites. ANF decreased MAP (-10.4 +/- 2.4 mmHg) and HR (-9.8 +/- 3.0 beats/min) in 25 of 41 depressor sites distributed throughout the caudal VLM (CVLM); no response was observed in the other 16 CVLM sites. Brain natriuretic peptide (BNP) was microinjected (20 nl of 10(-7) M) in 21 VLM sites, before or after microinjection of ANF. BNP and ANF elicited similar results in 17 sites, a decline in MAP and HR in 10 sites, and no effect in 7 sites. In the remaining four cases ANF caused a decline in MAP and in HR, whereas BNP had minimal or no effect. Cardiovascular responses to ANF microinjection into the RVLM and CVLM support the hypothesis that ANF is involved in the transmission of baroreceptor information from the nucleus tractus solitarii to these medullary regions. The similarity of the results obtained with BNP and ANF suggests that these peptides may serve similar roles in medullary pathways involved in the control of the cardiovascular system. |
| Databáze: | OpenAIRE |
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