Does acute hyperglycemia alter rat aortic depressor nerve function?
Because it is not known where in the reflex arch, i.e., afference, central nervous system or efferences, hyperglycemia affects baroreflex function, the present study examined the effect of short-term (30 min) hyperglycemia on aortic depressor nerve function measured by a mean arterial pressure vs ao...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Divulgação Científica
2007-11-01
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| Series: | Brazilian Journal of Medical and Biological Research |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001100017 |
| _version_ | 1818064048466427904 |
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| author | D.A. Huber J.M. do Carmo J.A. Castania R. Fazan Jr H.C. Salgado |
| author_facet | D.A. Huber J.M. do Carmo J.A. Castania R. Fazan Jr H.C. Salgado |
| author_sort | D.A. Huber |
| collection | DOAJ |
| description | Because it is not known where in the reflex arch, i.e., afference, central nervous system or efferences, hyperglycemia affects baroreflex function, the present study examined the effect of short-term (30 min) hyperglycemia on aortic depressor nerve function measured by a mean arterial pressure vs aortic depressor nerve activity curve, fitted by sigmoidal regression, or by cross-spectral analysis between mean arterial pressure and aortic depressor nerve activity. Anesthetized male Wistar rats received an intravenous bolus (0.25 mL) injection, followed by 30 min of infusion (1 mL/h) of 30% glucose (N = 14). Control groups received a bolus injection and infusion of 0.9% saline (N = 14), or 30% mannitol (N = 14). Glucose significantly increased both blood glucose and plasma osmolarity (P < 0.05). Mean arterial pressure did not change after glucose, saline or mannitol infusion. Mean arterial pressure vs nerve activity curves were identical before and 10 and 30 min after the beginning of glucose, saline or mannitol infusion. Slow (0.3 Hz) oscillations of arterial pressure were induced by controlled bleeding, and cross-spectral analysis was applied to arterial pressure and aortic nerve activity. Transfer function magnitude (aortic depressor nerve activity/mean arterial pressure ratio in the frequency domain) was calculated as an index of gain of the aortic depressor nerve. Transfer function magnitude was similar in all groups during induced or spontaneous oscillations of arterial pressure. In conclusion, the present study demonstrates, by means of two different approaches for assessing baroreceptor function, that aortic depressor nerve activity was not altered by short-term (30 min) hyperglycemia. |
| first_indexed | 2024-12-10T14:29:48Z |
| format | Article |
| id | doaj.art-cb2721d2b24543719e6524835772c6f6 |
| institution | Directory Open Access Journal |
| issn | 0100-879X 1414-431X |
| language | English |
| last_indexed | 2024-12-10T14:29:48Z |
| publishDate | 2007-11-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-cb2721d2b24543719e6524835772c6f62022-12-22T01:44:59ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X2007-11-0140111567157610.1590/S0100-879X2007001100017Does acute hyperglycemia alter rat aortic depressor nerve function?D.A. HuberJ.M. do CarmoJ.A. CastaniaR. Fazan JrH.C. SalgadoBecause it is not known where in the reflex arch, i.e., afference, central nervous system or efferences, hyperglycemia affects baroreflex function, the present study examined the effect of short-term (30 min) hyperglycemia on aortic depressor nerve function measured by a mean arterial pressure vs aortic depressor nerve activity curve, fitted by sigmoidal regression, or by cross-spectral analysis between mean arterial pressure and aortic depressor nerve activity. Anesthetized male Wistar rats received an intravenous bolus (0.25 mL) injection, followed by 30 min of infusion (1 mL/h) of 30% glucose (N = 14). Control groups received a bolus injection and infusion of 0.9% saline (N = 14), or 30% mannitol (N = 14). Glucose significantly increased both blood glucose and plasma osmolarity (P < 0.05). Mean arterial pressure did not change after glucose, saline or mannitol infusion. Mean arterial pressure vs nerve activity curves were identical before and 10 and 30 min after the beginning of glucose, saline or mannitol infusion. Slow (0.3 Hz) oscillations of arterial pressure were induced by controlled bleeding, and cross-spectral analysis was applied to arterial pressure and aortic nerve activity. Transfer function magnitude (aortic depressor nerve activity/mean arterial pressure ratio in the frequency domain) was calculated as an index of gain of the aortic depressor nerve. Transfer function magnitude was similar in all groups during induced or spontaneous oscillations of arterial pressure. In conclusion, the present study demonstrates, by means of two different approaches for assessing baroreceptor function, that aortic depressor nerve activity was not altered by short-term (30 min) hyperglycemia.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001100017PressoreceptorsHyperglycemiaArterial pressureSpectral analysis |
| spellingShingle | D.A. Huber J.M. do Carmo J.A. Castania R. Fazan Jr H.C. Salgado Does acute hyperglycemia alter rat aortic depressor nerve function? Brazilian Journal of Medical and Biological Research Pressoreceptors Hyperglycemia Arterial pressure Spectral analysis |
| title | Does acute hyperglycemia alter rat aortic depressor nerve function? |
| title_full | Does acute hyperglycemia alter rat aortic depressor nerve function? |
| title_fullStr | Does acute hyperglycemia alter rat aortic depressor nerve function? |
| title_full_unstemmed | Does acute hyperglycemia alter rat aortic depressor nerve function? |
| title_short | Does acute hyperglycemia alter rat aortic depressor nerve function? |
| title_sort | does acute hyperglycemia alter rat aortic depressor nerve function |
| topic | Pressoreceptors Hyperglycemia Arterial pressure Spectral analysis |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007001100017 |
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